allenai/sciq · Datasets at Hugging Face

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What year did the soho spacecraft first started to operate?	1987	2012	2006	1996	Humans have sent spacecraft up to study our star. The SOHO spacecraft has been in operation since 1996. The craft orbits the Sun in step with Earth but closer to it. SOHO has sent back amazing images. Onboard instruments have also sent back mountains of data. The data is mostly about the Sun's outer layers.
Concentration of what, the substance left behind when ocean water evaporates, is about 3.5 percent?	quartz	hydrogen	sugar	salts	Dissolved mineral salts wash into the ocean. As ocean water evaporates, it leaves the salts behind. This makes the water saltier. Ocean water is about 3.5 percent salts. The main salt is sodium chloride.
What has a distinct front and back end?	imipenem sphere	hydro sphere	heroclix sphere	volvox sphere	The Volvox sphere has a distinct front and back end. The colony of cells can swim in a coordinated fashion. The cells have eyespots, which are more developed in the cells near the front. This enables the colony to swim towards light.
In how many basic was can substances cross the plasma membrane?	four	one	three	two	If a cell were a house, the plasma membrane would be walls with windows and doors. Moving things in and out of the cell is an important role of the plasma membrane. It controls everything that enters and leaves the cell. There are two basic ways that substances can cross the plasma membrane: passive transport and active transport.
What type of cells have chloroplasts?	human cells	simple cells	animal cells	plant cells	Plants are multicellular eukaryotes with cell walls made of cellulose. Plant cells also have chloroplasts. In addition, plants have specialized reproductive organs. These are structures that produce reproductive cells. Male reproductive organs produce sperm, and female reproductive organs produce eggs. Male and female reproductive organs may be on the same or different plants.
What is the term for disease-causing agents, such as bacteria and viruses?	vaccines	spores	parasites	pathogens	The body’s first line of defense consists of different types of barriers that keep most pathogens out of the body. Pathogens are disease-causing agents, such as bacteria and viruses. These and other types of pathogens are described in Figure below . Regardless of the type of pathogen, however, the first line of defense is always the same.
To figure out the height of a wave you measure the distance between the crest and what?	crater	drift	core	trough	The figure above also shows how the size of waves is measured ( Figure above ). The highest point of a wave is the crest . The lowest point is the trough . The vertical distance between a crest and a trough is the wave height . Wave height is also called amplitude . The horizontal distance between two crests is the wavelength . Both amplitude and wavelength are measures of wave size.
Humans possess greater diversity of what type, compared to laboratory animals?	pathogens	lifespans	elements	genetics
What system can be used by scientists to express very small numbers?	certain diffusion	similar notation	scientific diffusion	scientific notation	Very small numbers can also be expressed using scientific notation. The mass of an electron in decimal notation is 0.000000000000000000000000000911 grams. In scientific notation, the mass is expressed as 9.11 × 10 -28 g. Notice that the value of the exponent is chosen so that the coefficient is between 1 and 10.
An unknown genotype can be determined by observing what, the term for characteristics of the resulting offspring?	chromosonal variations	abnormalities	clusters	phenotypes	Consider the following example: Suppose you have a purple and white flower and purple color ( P ) is dominant to white ( p ). The white flower must be homozygous for the recessive allele, but the genotype of the purple flower is unknown. It could be either PP or Pp . A testcross will determine the organism's genotype. The unknown genotype can be determined by observing the phenotypes of the resulting offspring. If crossing the unknown dominant phenotype ( PP or Pp genotype) individual with the recessive phenotype individual produces only dominant phenotypes (no recessive), then the unknown individual is homozygous dominant. If any recessive phenotypic individuals result from the cross, then the unknown individual must carry the recessive allele, and have the heterozygous genotype.
Wind power, solar power, hydropower, and geothermal power are called renewable sources of energy or what other term?	conservative energy	mandatory energy	specific energy	alternative energy	Alternative energy sources include wind power, solar power, hydropower, and geothermal power.
How much electricity is generated by an average car battery?	six volts	ten volts	eight volts	twelve volts	The description given above describes the process that occurs in one cell of a lead-acid battery. Because cars require a battery with a higher voltage than can be obtained with a single cell, car batteries generally consist of several cells connected together to produce the desired voltage output. A typical car battery will generate twelve volts of electricity.
What is the term for a cellular "scaffolding" that crisscrosses the cytoplasm?	collagen	protoskeleton	cellulose	cytoskeleton	The cytoskeleton is a cellular "scaffolding" or "skeleton" that crisscrosses the cytoplasm. All eukaryotic cells have a cytoskeleton, and recent research has shown that prokaryotic cells also have a cytoskeleton. The eukaryotic cytoskeleton is made up of a network of long, thin protein fibers and has many functions. It helps to maintain cell shape. It holds organelles in place, and for some cells, it enables cell movement. The cytoskeleton also plays important roles in both the intracellular movement of substances and in cell division. Certain proteins act like a path that vesicles and organelles move along within the cell. The threadlike proteins that make up the cytoskeleton continually rebuild to adapt to the cell's constantly changing needs. Three main kinds of cytoskeleton fibers are microtubules, intermediate filaments, and microfilaments.
What common code do all known living organisms use?	code of ethics	biochemical	Morse code	genetic	The genetic code is universal. All known living organisms use the same genetic code. This shows that all organisms share a common evolutionary history.
What are 2 common growth patterns of population?	organic and inorganic	migratory and logistic	exponential and economical	exponential and logistic	Populations may show different patterns of growth. The growth pattern depends partly on the conditions under which a population lives. Two common growth patterns are exponential growth and logistic growth. Both are represented in Figure below .
Solutions to schrödinger’s equation involve four special numbers called what?	light numbers	gravity numbers	linear numbers	quantum numbers	Solutions to Schrödinger’s equation involve four special numbers called quantum numbers . (Three of the numbers, , , and , come from Schrödinger’s equation, and the fourth one comes from an extension of the theory). These four numbers completely describe the energy of an electron. Each electron has exactly four quantum numbers, and no two electrons have the same four numbers. The statement that no two electrons can have the same four quantum numbers is known as the Pauli exclusion principle .
What is the only human cell with flagella?	Feces	egg	saliva	sperm	Sperm cells are the only human cell with flagella . This is because of their need to "swim" long distances to reach an egg for fertilization.
What can be described as a tiny male gametophyte enclosed in a tough capsule?	dna	seed	cell	grain of pollen	A grain of pollen is a tiny male gametophyte enclosed in a tough capsule (see Figure below ). It carries sperm to an ovule while preventing it from drying out. Pollen grains can’t swim, but they are very light, so the wind can carry them. Therefore, they can travel through air instead of water.
What is the largest artery in the body called?	radial	ventricular	carotid	aorta	Flaps of tissue called valves separate the heart’s chambers. Valves keep blood flowing in just one direction through the heart. For example, a valve at the bottom of the right atrium opens to let blood flow from the right atrium to the right ventricle. Then the valve closes so the blood can’t flow back into the right atrium.
Fertilization occurs if a sperm enters the egg while it is passing through what tube?	vaginal	ovarian	anterior	fallopian	Fertilization occurs if a sperm enters the egg while it is passing through the fallopian tube. When this happens, the egg finally completes meiosis. This results in two daughter cells that are different in size. The smaller cell is called a polar body . It contains very little cytoplasm. It soon breaks down and disappears. The larger cell is the egg. It contains most of the cytoplasm. This will develop into a child.
When the smooth muscle relaxes, the arterioles dilate, allowing blood to enter the what?	veins	bones	arteries	capillaries
What to tadpoles develop into?	snakes	toads	mosquitos	frogs	Frogs typically lay their eggs in puddles, ponds, or lakes. Their larvae, or tadpoles , have gills, a tail, but no legs, and need to live in water. If fact, they are quite similar to a fish. Tadpoles develop into adult frogs in water ( Figure below ). During this transformation, they develop lungs, lose their tails and form their four legs.
What part of the body do fish use to absorb oxygen?	under belly	dorsal fin	tail fin	gills	In order to absorb oxygen from the water, fish use gills ( Figure below ). Gills take dissolved oxygen from water as the water flows over the surface of the gill.
The electrons in a water molecule are more concentrated around the more highly charged oxygen nucleus than around this?	peroxide nuclei	helium nuclei	carbon nuclei	hydrogen nuclei	We will find in Atomic Physics that the orbits of electrons are more properly viewed as electron clouds with the density of the cloud related to the probability of finding an electron in that location (as opposed to the definite locations and paths of planets in their orbits around the Sun). This cloud is shifted by the Coulomb force so that the atom on average has a separation of charge. Although the atom remains neutral, it can now be the source of a Coulomb force, since a charge brought near the atom will be closer to one type of charge than the other. Some molecules, such as those of water, have an inherent separation of charge and are thus called polar molecules. Figure ⎛ ⎞ 19.19 illustrates the separation of charge in a water molecule, which has two hydrogen atoms and one oxygen atom ⎝H 2 O⎠ . The water molecule is not symmetric—the hydrogen atoms are repelled to one side, giving the molecule a boomerang shape. The electrons in a water molecule are more concentrated around the more highly charged oxygen nucleus than around the hydrogen nuclei. This makes the oxygen end of the molecule slightly negative and leaves the hydrogen ends slightly positive. The inherent separation of charge in polar molecules makes it easier to align them with external fields and charges. Polar molecules therefore exhibit greater polarization effects and have greater dielectric constants. Those who study chemistry will find that the polar nature of water has many effects. For example, water molecules gather ions much more effectively because they have an electric field and a separation of charge to attract charges of both signs. Also, as brought out in the previous chapter, polar water provides a shield or screening of the electric fields in the highly charged molecules of interest in biological systems.
What is the layer of ground below the surface that is always frozen, even in the summer?	upper crust	tundra	bedrock	permafrost	Polar tundra climates occur near the poles. Tundra climates have permafrost. Permafrost is layer of ground below the surface that is always frozen, even in the summer. Only small plants, such as mosses, can grow in this climate.
What is usually the prey of a protist?	proteins	pathogens	algae	bacteria	The protist wraps around its prey, which is usually bacteria.
What concentrates wave energy or disperses it?	wave reflection	wave diffusion	a prism	wave refraction	Wave refraction either concentrates wave energy or disperses it. In quiet water areas, such as bays, wave energy is dispersed. This allows sand to be deposited. Land that sticks out into the water is eroded by the strong wave energy. The wave energy concentrates its power on the wave-cut cliff .
In plants and algae, photosynthesis takes place in which organelles?	cells	stems	fibroblasts	chloroplasts	In plants and algae, photosynthesis takes place in organelles called chloroplasts. Chloroplasts contain stacks of membranes called thylakoids, which contain chlorophyll. Thylakoids are surrounded by a fluid-filled space called stroma.
What produces sound waves that travel outward in all directions in water?	amplifiers	echo chamber	ultrasound machines	echo sounders	During World War II, battleships and submarines carried echo sounders. Their goal was to locate enemy submarines ( Figure below ). Echo sounders produce sound waves that travel outward in all directions. The sound waves bounce off the nearest object and then return to the ship. Scientists know the speed of sound in seawater. They then can calculate the distance to the object that the sound wave hit. Most of these sound waves did not hit submarines. They instead were used to map the ocean floor.
The roots of a plant take in nutrients and what vital substance?	Soil	air	Ash	water
Carbon fixation is the first step of what cycle involving light reactions?	water cycle	sun cycle	life cycle	calvin cycle	As Melvin Calvin discovered, carbon fixation is the first step of a cycle. Like an electron transport chain, the Calvin Cycle, shown in Figure below , transfers energy in small, controlled steps. Each step pushes molecules uphill in terms of energy content. Recall that in the electron transfer chain, excited electrons lose energy to NADPH and ATP. In the Calvin Cycle, NADPH and ATP formed in the light reactions lose their stored chemical energy to build glucose.
What are the attractive forces that occur between polar molecules called?	ion-dipole forces	induced-dipole forces	particle - dipole forces	dipole-dipole forces	Dipole-dipole forces are the attractive forces that occur between polar molecules. A molecule of hydrogen chloride has a partially positive hydrogen atom and a partially negative chlorine atom. In a collection of many hydrogen chloride molecules, they will align themselves so that the oppositely charged regions of neighboring molecules are near each other.
The production of multiple copies of a single gene is called?	gene change	cell cloning	gene variation	gene cloning
Fossil fuels are made out of what two objects?	soil and animals	gases and animals	plants and water	plants and animals	Fossil fuels are made from plants and animals that lived hundreds of millions of years ago. The plants and animals died. Their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels.
Amoebas and paramecia are examples of what?	protists	vertebrates	bacteria	protozoa	Examples of protozoa include amoebas and paramecia.
Name the bacteria that make food through photosynthesis and release oxygen into the air?	algae	fusobacteria	phytoplankton	cyanobacteria	Bacteria called cyanobacteria are very important. They are bluish green in color (see Figure below ) because they contain chlorophyll (but not chloroplasts, of course). They make food through photosynthesis and release oxygen into the air. These bacteria were probably responsible for adding oxygen to the air on early Earth. This changed the planet’s atmosphere. It also changed the direction of evolution. Ancient cyanobacteria also may have evolved into the chloroplasts of plant cells.
What simple machine consists of a bar that rotates around a fixed point called the fulcrum?	catapult	battering ram	rotor	lever	A lever is a simple machine that consists of a bar that rotates around a fixed point called the fulcrum. There are three classes of levers. Depending on its class, a lever may have an ideal mechanical advantage that is less than, equal to, or greater than 1. First-class levers also change the direction of the input force.
Which carbohydrate is produced by photosynthesis?	sugar	protein	insulin	glucose	Glucose is the carbohydrate produced by photosynthesis. Energy-rich glucose is delivered through your blood to each of your cells.
What term is used to describe the line of latitude right in the middle of the planet?	pole	Prime Meridian	orbital	equator	Lines of latitude circle around Earth. The equator is a line of latitude right in the middle of the planet. The equator is an equal distance from both the North and South Pole. If you know your latitude, you know how far you are north or south of the equator.
What is the opening formed between adjacent vertebrae for the exit of a spinal nerve called?	spinous process	inferior vertebral notch	sympathetic ganglion	intervertebral foramen	Figure 7.24 Intervertebral Disc The bodies of adjacent vertebrae are separated and united by an intervertebral disc, which provides padding and allows for movements between adjacent vertebrae. The disc consists of a fibrous outer layer called the anulus fibrosus and a gel-like center called the nucleus pulposus. The intervertebral foramen is the opening formed between adjacent vertebrae for the exit of a spinal nerve.
What two planets is the asteroid belt found between?	saturn and uranus	mars and venus	earth and venus	mars and jupiter	Hundreds of thousands of asteroids have been found in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month! The majority are located in between the orbits of Mars and Jupiter. This region is called the asteroid belt , as shown in Figure below . There are many thousands of asteroids in the asteroid belt. Still, their total mass adds up to only about 4 percent of Earth’s Moon.
Neon is an example of what kind of gas?	natural	ideal	inert	noble	Once we reach neon, a noble gas, all of the 2p orbitals will be completely full. Neon has a configuration of 1s 2 2s 2 2p 6 . Any further electrons will need to go in the next highest energy orbital, which would be the 3s orbital.
Many organisms look very similar to other organisms because they may be from the same what?	parasites	nutrients	area	species
What type of compound is hydrogen chloride?	ionic	polar	metal	covalent	The largest, most complex covalent molecules have thousands of atoms. Examples include proteins and carbohydrates, which are compounds in living things. The smallest, simplest covalent compounds have molecules with just two atoms. An example is hydrogen chloride (HCl). It consists of one hydrogen atom and one chlorine atom, as you can see in the Figure below . You can watch an animation of hydrogen chloride forming at the following URL.
What kind of volcanic eruptions are less deadly?	explosive	non-dormant	serial eruptions	non-explosive	Some volcanic eruptions are non-explosive ( Figure below ). This happens when there is little or no gas. The lava is thin, fluid and runny. It flows over the ground like a river. People generally have a lot of warning before a lava flow like this reaches them, so non-explosive eruptions are much less deadly. They may still be destructive to property, though. Even when we know that a lava flow is approaching, there are few ways of stopping it!.
Where do most ecosystems get their energy from?	water	earth	heat	sun	Most ecosystems get their energy from the Sun. Only producers can use sunlight to make usable energy. Producers convert the sunlight into chemical energy or food. Consumers get some of that energy when they eat producers. They also pass some of the energy on to other consumers when they are eaten. In this way, energy flows from one living thing to another.
When a solute dissolves into a solvent what is that called?	mixing	solubility	viscosity	enthalpy	Enthalpy changes also occur when a solute undergoes the physical process of dissolving into a solvent. Hot packs and cold packs (see Figure below ) use this property. Many hot packs use calcium chloride, which releases heat when it dissolves according to the equation below.
The smallest part of an element that maintains the identity of that element is called what?	neutron	lattice	nucleus	atom	Note Sometimes the word pure is added to substance, but this is not absolutely necessary. By definition, any single substance is pure. The smallest part of an element that maintains the identity of that element is called an atom. Atoms are extremely tiny; to make a line 1 inch long, you would need 217 million iron atoms. The smallest part of a compound that maintains the identity of that compound is called a molecule. Molecules are composed of atoms that are attached together and behave as a unit. Scientists usually work with millions and millions of atoms and molecules at a time. When a scientist is working with large numbers of atoms or molecules at a time, the scientist is studying the macroscopic view of the universe. However, scientists can also describe chemical events on the level of individual atoms or molecules, which is referred to as the microscopic viewpoint. We will see examples of Saylor URL: http://www. saylor. org/books.
Varves form in lakes covered by what?	soot	coral reef	bridges	ice	Varves form in lakes covered by ice. Varves are useful to scientists for understanding climate.
Speed takes distance and what else into account?	energy	gravity	matter	time	Speed just takes distance and time into account. How might direction be considered as well?.
Which division of the autonomic nervous system controls processes like digestion, heartbeat, and breathing?	dopaminergic	endocrine	synaptic	parasympathetic	The parasympathetic division controls internal organs and glands during the rest of the time. It controls processes like digestion, heartbeat, and breathing when there is not an emergency.
What does the ovule develop into after fertilization?	germ	pollen	zygote	seed	An ovule is a female reproductive structure in seed plants. It contains a tiny female gametophyte. The gametophyte produces an egg cell. After the egg is fertilized by sperm, the ovule develops into a seed.
What is a key factor in the growth of populations?	assimilation	legislation	gentrification	immigration	Moving into an area, or immigration, is a key factor in the growth of populations. Shown above is actual vintage luggage left by some of the millions of immigrants who came through Ellis Island and into the United States.
Air is said to reach what point, a term used by meteorologists, when humidity increases or temperature decreases?	freezing point	bubble point	its dip point	its dew point	Air reaches its dew point when humidity increases or temperature decreases.
In neurons, what often involves gated sodium channels?	polarization	fermentation	excitation	depolarization
Line graphs are especially useful for showing changes over what?	velocity	space	energy	time	Line graphs are especially useful for showing changes over time. The line graph in Figure below shows how distance from school changed over time when some students went on a class trip.
After a massive eruption what will a mountain collapsing above an empty chamber create?	valley	crater	cavern	caldera	During a massive eruption all of the material may be ejected from a magma changer. Without support, the mountain above the empty chamber may collapse. This produces a huge caldera . Calderas are generally round, bowl-shaped formations like the picture in Figure below .
The posterior half of the foot is formed by seven tarsal bones. the most superior of these bones is called?	calcareous	metatarsal	patella	talus	Tarsal Bones The posterior half of the foot is formed by seven tarsal bones (Figure 8.19). The most superior bone is the talus. This has a relatively square-shaped, upper surface that articulates with the tibia and fibula to form the ankle joint. Three areas of articulation form the ankle joint: The superomedial surface of the talus bone articulates with the medial malleolus of the tibia, the top of the talus articulates with the distal end of the tibia, and the lateral side of the talus articulates with the lateral malleolus of the fibula. Inferiorly, the talus articulates with the calcaneus (heel bone), the largest bone of the foot, which forms the heel. Body weight is transferred from the tibia to the talus to the calcaneus, which rests on the ground. The medial calcaneus has a prominent bony extension called the sustentaculum tali (“support for the talus”) that supports the medial side of the talus bone.
What helps to regulate consciousness, arousal, and sleep states?	cerebral cortex	hypothalamus	hippocampus	thalamus	Basal Ganglia Interconnected brain areas called the basal ganglia (or basal nuclei), shown in Figure 35.20b, play important roles in movement control and posture. Damage to the basal ganglia, as in Parkinson’s disease, leads to motor impairments like a shuffling gait when walking. The basal ganglia also regulate motivation. For example, when a wasp sting led to bilateral basal ganglia damage in a 25-year-old businessman, he began to spend all his days in bed and showed no interest in anything or anybody. But when he was externally stimulated—as when someone asked to play a card game with him—he was able to function normally. Interestingly, he and other similar patients do not report feeling bored or frustrated by their state. Thalamus The thalamus (Greek for “inner chamber”), illustrated in Figure 35.24, acts as a gateway to and from the cortex. It receives sensory and motor inputs from the body and also receives feedback from the cortex. This feedback mechanism can modulate conscious awareness of sensory and motor inputs depending on the attention and arousal state of the animal. The thalamus helps regulate consciousness, arousal, and sleep states. A rare genetic disorder called fatal familial insomnia causes the degeneration of thalamic neurons and glia. This disorder prevents affected patients from being able to sleep, among other symptoms, and is eventually fatal.
Some fish will be over-fished to the point that their species ceases to exist, which is also known as what?	abundance	endangered	accumulation	extinction	will inevitably make it more difficult and costly to grow food. The world’s growing human population faces significant challenges in the increasing costs and other difficulties associated with producing food. Wild Food Sources In addition to growing crops and raising food animals, humans obtain food resources from wild populations, primarily wild fish populations. For about one billion people, aquatic resources provide the main source of animal protein. But since 1990, production from global fisheries has declined. Despite considerable effort, few fisheries on Earth are managed sustainability. Fishery extinctions rarely lead to complete extinction of the harvested species, but rather to a radical restructuring of the marine ecosystem in which a dominant species is so over-harvested that it becomes a minor player, ecologically. In addition to humans losing the food source, these alterations affect many other species in ways that are difficult or impossible to predict. The collapse of fisheries has dramatic and long-lasting effects on local human populations that work in the fishery. In addition, the loss of an inexpensive protein source to populations that cannot afford to replace it will increase the cost of living and limit societies in other ways. In general, the fish taken from fisheries have shifted to smaller species and the larger species are overfished. The ultimate outcome could clearly be the loss of aquatic systems as food sources.
Not surprisingly, what is the function of the most developed part of a bird's brain?	controlling thought	controlling digestion	controlling breeding	controlling flight	Birds have a large brain relative to the size of their body. Not surprisingly, the part of the brain that controls flight is the most developed part. The large brain size of birds is also reflected by their high level of intelligence and complex behavior. In fact, birds such as crows and ravens may be more intelligent than many mammals. They are smart enough to use objects such as twigs for tools. They also demonstrate planning and cooperation. Most birds have a poor sense of smell, but they make up for it with their excellent sense of sight. Predatory birds have especially good eyesight. Hawks, for example, have vision that is eight times sharper than human vision.
What type of roots enable a plant to grow on another plant?	mites	Sickness	endemic	epiphytic	Epiphytic roots enable a plant to grow on another plant. For example, the epiphytic roots of orchids develop a spongy tissue to absorb moisture. The banyan tree (Ficus sp. ) begins as an epiphyte, germinating in the branches of a host tree; aerial roots develop from the branches and eventually reach the ground, providing additional support (Figure 30.20). In screwpine (Pandanus sp. ), a palm-like tree that grows in sandy tropical soils, aboveground prop roots develop from the nodes to provide additional support.
What is the distance north or south of the equator called?	elevation	longitude	circumference	latitude	Latitude is the distance north or south of the Equator. It is expressed as a number between 0° and 90° north or south.
In response to a cut, mast cells secrete histamines that cause nearby capillaries to do what?	constrict	harden	narrow	dilate	Figure 42.5 In response to a cut, mast cells secrete histamines that cause nearby capillaries to dilate. Neutrophils and monocytes leave the capillaries. Monocytes mature into macrophages. Neutrophils, dendritic cells and macrophages release chemicals to stimulate the inflammatory response. Neutrophils and macrophages also consume invading bacteria by phagocytosis.
What is the term for an ionic compound that produces positive hydrogen ions when dissolved in water?	base	hydrocarbon	sulfur	acid	An acid is an ionic compound that produces positive hydrogen ions when dissolved in water. Acids taste sour and turn blue litmus paper red.
The stems of all vascular plants get longer through primary growth. this occurs in primary meristem at the tips and ______ of the stems.	layers	edges	bottoms	nodes	The stems of all vascular plants get longer through primary growth. This occurs in primary meristem at the tips and nodes of the stems. Most stems also grow in thickness through secondary growth. This occurs in secondary meristem, which is located in and around the vascular tissues. Secondary growth forms secondary vascular tissues and bark. In many trees, the yearly growth of new vascular tissues results in an annual growth ring like the one in Figure below . When a tree is cut down, the rings in the trunk can be counted to estimate the tree’s age.
What kind of waves are electromagnetic waves?	inverse	amplitude	curved	transverse	In this lesson, you learned that electromagnetic waves are transverse waves. Like other transverse waves, electromagnetic waves have certain properties.
What process is involved in the formation of a waterfall, when a stream flows from an area of harder to softer rock?	evaporation	calcification	migration	erosion	Mountain streams may erode waterfalls. A waterfall forms where a stream flows from an area of harder to softer rock ( Figure below ). The water erodes the softer rock faster than the harder rock. This causes the stream bed to drop down, like a step. This creates a waterfall. As erosion continues, the waterfall gradually moves upstream.
Meissner’s corpuscles are not as plentiful in the palms as they are in the what other part of the hand?	cuticles	bones	fingernails	fingertips	Which of the following statements about mechanoreceptors is false? a. Pacini corpuscles are found in both glabrous and hairy skin. Merkel’s disks are abundant on the fingertips and lips. Ruffini endings are encapsulated mechanoreceptors. Meissner’s corpuscles extend into the lower dermis. Meissner’s corpuscles, (shown in Figure 36.6) also known as tactile corpuscles, are found in the upper dermis, but they project into the epidermis. They, too, are found primarily in the glabrous skin on the fingertips and eyelids. They respond to fine touch and pressure, but they also respond to low-frequency vibration or flutter. They are rapidly adapting, fluid-filled, encapsulated neurons with small, well-defined borders and are responsive to fine details. Like Merkel’s disks, Meissner’s corpuscles are not as plentiful in the palms as they are in the fingertips.
What are the two types of earth crust?	amorphous and continental	reflective and continental	micro and continental	oceanic and continental	The crust is less than 1% of Earth by mass. The two types are oceanic crust and continental crust.
What is determined by the energy of the disturbance that causes the wave?	frequency	wavelength	Ohm	wave amplitude	Wave amplitude is determined by the energy of the disturbance that causes the wave. A wave caused by a disturbance with more energy has greater amplitude.
What is made from the minerals in rocks known as bauxite?	coins	glass	titanium	aluminum	Aluminum is made from the minerals in rocks known as bauxite.
What is a defining feature of deformed sedimentary rocks?	not magnetic	not solid	only horizontal	not horizontal	Sedimentary rocks that are not horizontal have been deformed.
Resemblance to other species can serve as protection to what category of species?	consumer	producer	predator	prey
What type of cells make up the epidermis of a leaf?	mesophyll	chloroplasts	endothermic cells	dermal cells	The epidermis of the leaf consists of a single layer of tightly-packed dermal cells. They secrete waxy cuticle to prevent evaporation of water from the leaf. The epidermis has tiny pores called stomata (singular, stoma) that control transpiration and gas exchange with the air. For photosynthesis, stomata must control the transpiration of water vapor and the exchange of carbon dioxide and oxygen. Stomata are flanked by guard cells that swell or shrink by taking in or losing water through osmosis . When they do, they open or close the stomata (see Figure below ).
What carries warm or cold water throughout the world’s oceans?	earth rotation	gravity	pipes	ocean currents	Ocean currents carry warm or cold water throughout the world’s oceans. They help to even out the temperatures in the oceans. This also affects the temperature of the atmosphere and the climate around the world. Currents that are near shore have a direct impact on climate. They may make the climate much colder or warmer. You can see examples of this in Figure below .
What type of resource cannot be replaced as easily as it is consumed?	untapped	biological	renewable	nonrenewable	A nonrenewable resource is one that cannot be replaced as easily as it is consumed. Fossil fuels are an example of nonrenewable resources. They take millions of years to form naturally, and so they cannot be replaced as fast as they are consumed. To take the place of fossil fuel use, alternative energy resources are being developed. These alternative energy sources often utilize renewable resources. The following are examples of sustainable alternative energy resources:.
What substances are involved in most of the chemical reactions that take place in organisms, including digestion?	vitamins	proteins	hormones	enzymes	Enzymes are involved in most of the chemical reactions that take place in organisms. About 4,000 such reactions are known to be catalyzed by enzymes, but the number may be even higher. In animals, an important function of enzymes is to help digest food. Digestive enzymes speed up reactions that break down large molecules of carbohydrates, proteins, and fats into smaller molecules the body can use. Without digestive enzymes, animals would not be able to break down food molecules quickly enough to provide the energy and nutrients they need to survive.
What occurs when the immune system is not working properly?	anemia	allergy	cancer	immunodeficiency	Immunodeficiency occurs when the immune system is not working properly. As a result, it cannot fight off pathogens that a normal immune system would be able to resist. Rarely, the problem is caused by a defective gene. More often, it is acquired during a person’s lifetime. Immunodeficiency may occur for a variety of reasons:.
The force that a magnet exerts on certain materials is called what?	centripetal force	stellar force	velocity force	magnetic force	The force that a magnet exerts on certain materials, including other magnets, is called magnetic force . The force is exerted over a distance and includes forces of attraction and repulsion. North and south poles of two magnets attract each other, while two north poles or two south poles repel each other. A magnet can exert force over a distance because the magnet is surrounded by a magnetic field . In the Figure below , you can see the magnetic field surrounding a bar magnet. Tiny bits of iron, called iron filings, were placed under a sheet of glass. When the magnet was placed on the glass, it attracted the iron filings. The pattern of the iron filings shows the lines of force that make up the magnetic field of the magnet. The concentration of iron filings near the poles indicates that these areas exert the strongest force. You can also see how the magnetic field affects the compasses placed above the magnet. To see an animated magnetic field of a bar magnet, go to this URL: http://micro. magnet. fsu. edu/electromag/java/magneticlines/.
What is applied to a rock to make it bend and flow?	acid	phosphorus	weathering	stress	The amount of stress on a rock may be greater than the rock’s strength. In that case, the rock will change and deform ( Figure below ). Deep within the Earth, the pressure is very great. A rock behaves like a stretched rubber band. When the stress stops, the rock goes back to its original shape. If more stress is applied to the rock, it bends and flows. It does not return to its original shape. Near the surface, if the stress continues, the rock will fracture and break.
What is the function of chloroplasts that are found in plant and algal cells?	glycolysis	mitosis	spermatogenesis	photosynthesis	Actually, almost all organisms obtain their energy from photosynthetic organisms. For example, if a bird eats a caterpillar, then the bird gets the energy that the caterpillar gets from the plants it eats. So the bird indirectly gets energy that began with the glucose formed through photosynthesis. Therefore, the process of photosynthesis is central to sustaining life on Earth. In eukaryotic organisms, photosynthesis occurs in chloroplasts . Only cells with chloroplasts—plant cells and algal (protist) cells—can perform photosynthesis. Animal cells and fungal cells do not have chloroplasts and, therefore, cannot photosynthesize. That is why these organisms, as well as the non-photosynthetic protists, rely on other organisms to obtain their energy. These organisms are heterotrophs.
What passes through the prostate gland immediately inferior to the bladder before passing below the pubic symphysis?	cerebellum	rectum	vagina	urethra	Male Urethra The male urethra passes through the prostate gland immediately inferior to the bladder before passing below the pubic symphysis (see Figure 25.3b). The length of the male urethra varies between men but averages 20 cm in length. It is divided into four regions: the preprostatic urethra, the prostatic urethra, the membranous urethra, and the spongy or penile urethra. The preprostatic urethra is very short and incorporated into the bladder wall. The prostatic urethra passes through the prostate gland. During sexual intercourse, it receives sperm via the ejaculatory ducts and secretions from the seminal vesicles. Paired Cowper’s glands (bulbourethral glands) produce and secrete mucus into the urethra to buffer urethral pH during sexual stimulation. The mucus neutralizes the usually acidic environment and lubricates the urethra, decreasing the resistance to ejaculation. The membranous urethra passes through the deep muscles of the perineum, where it is invested by the overlying urethral sphincters. The spongy urethra exits at the tip (external urethral orifice) of the penis after passing through the corpus spongiosum. Mucous glands are found along much of the length of the urethra and protect the urethra from extremes of urine pH. Innervation is the same in both males and females.
Terrestrial animals lose water by evaporation from their skin and which surfaces?	pulmonary	anaerobic	digestive	respiratory
What color are leukocytes blood cells?	red	blue	black	white	The chemicals that trigger an inflammatory response attract leukocytes to the site of injury or infection. Leukocytes are white blood cells. Their role is to fight infections and get rid of debris. Leukocytes may respond with either a nonspecific or a specific defense.
What is something that all machines must overcome?	temperature	stress	work	friction	The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat greater than the actual mechanical advantage of the machine as it is used in the real world.
The conservation of momentum principle can be applied to systems as different as a comet striking earth and a gas containing huge numbers of atoms and these?	protons	particles	ions	molecules	The conservation of momentum principle can be applied to systems as different as a comet striking Earth and a gas containing huge numbers of atoms and molecules. Conservation of momentum is violated only when the net external force is not zero. But another larger system can always be considered in which momentum is conserved by simply including the source of the external force. For example, in the collision of two cars considered above, the two-car system conserves momentum while each one-car system does not. Making Connections: Take-Home Investigation—Drop of Tennis Ball and a Basketball Hold a tennis ball side by side and in contact with a basketball. Drop the balls together. (Be careful!) What happens? Explain your observations. Now hold the tennis ball above and in contact with the basketball. What happened? Explain your observations. What do you think will happen if the basketball ball is held above and in contact with the tennis ball?.
What are the small units that comprise nucleic acids?	chromosomes	genes	filaments	nucleotides	DNA and RNA are nucleic acids. Nucleic acids are built of small units called nucleotides.
Minerals that are not pure elements are made of what?	metalloids	isotopes	noble gases	chemical compounds	Minerals that are not pure elements are made of chemical compounds. For example, the mineral quartz is made of the compound silicon dioxide, or SiO 2 . This compound has one atom of the element silicon for every two atoms of the element oxygen.
What can be classified as monoprotic or polyprotic based on the number of acidic hydrogens they contain?	salts	ions	cations	acids	Acids can be classified as monoprotic or polyprotic based on the number of acidic hydrogens they contain.
What is the top part of water able to receive enough sunlight for photosynthesis called?	fantasmic zone	thymic zone	synthesis zone	photic zone	Only the top 200 meters or so of water receive enough sunlight for photosynthesis. This part of the water is called the photic zone. Below 200 meters, there is too little sunlight for photosynthesis to take place. This part of the water is called the aphotic zone. In this zone, food must come from other sources. It may be made by chemosynthesis, in which microorganisms use energy in chemicals instead of sunlight to make food. Or, food may drift down from the water above.
Different media affect what property of light?	temperature	density	color	speed	The speed of light is different in different media.
Signals from rods and cones can follow several different pathways in what structure of the eye?	lens	aperture	aqueous humor	retina
What is the term for getting used to something after being consistently exposed to it?	acceptance	modification	dissociation	habituation	One of the simplest ways of learning that occurs in just about all animals is habituation. Habituation means learning to get used to something after being exposed to it repeatedly. It usually involves getting used to something that is frightening or annoying but not dangerous.
What element do nuclear power plants use in fuel rods?	magnesium	plutonium	boron	uranium	Nuclear power plants use uranium in fuel rods. The fuel rods become nuclear waste. Nuclear waste can be dangerous for hundreds of thousands of years.
Where on earth do bacteria live?	blood	skin	water	all environments	Prokaryotes include Bacteria and Archaea. An individual prokaryote consists of a single cell without a nucleus. Bacteria live in virtually all environments on Earth. Archaea live everywhere on Earth, including extreme environments.
What type of waves radiate energy out from an earthquake's focus?	volcanic	Microwaves	abnormal	seismic	Geologists study earthquake waves to “see” Earth's interior. Waves of energy radiate out from an earthquake’s focus. These are called seismic waves ( Figure below ). Seismic waves change speed as they move through different materials. This causes them to bend. Some seismic waves do not travel through liquids or gases. Scientists use all of this information to understand what makes up the Earth’s interior.
What is a popular treatment for kidney failure?	electrolysis	psychotherapy	metastasis	dialysis	Uncontrolled diabetes may damage capillaries of nephrons. As a result, the kidneys lose much of their ability to filter blood. This is called kidney failure . The only cure for kidney failure is a kidney transplant, but it can be treated with dialysis. Dialysis is a medical procedure in which blood is filtered through a machine (see Figure below ).
What is critical for the formation of hemoglobin?	platelets	salts	proteins	iron ions	Minerals Minerals in food are inorganic compounds that work with other nutrients to ensure the body functions properly. Minerals cannot be made in the body; they come from the diet. The amount of minerals in the body is small—only 4 percent of the total body mass—and most of that consists of the minerals that the body requires in moderate quantities: potassium, sodium, calcium, phosphorus, magnesium, and chloride. The most common minerals in the body are calcium and phosphorous, both of which are stored in the skeleton and necessary for the hardening of bones. Most minerals are ionized, and their ionic forms are used in physiological processes throughout the body. Sodium and chloride ions are electrolytes in the blood and extracellular tissues, and iron ions are critical to the formation of hemoglobin. There are additional trace minerals that are still important to the body’s functions, but their required quantities are much lower. Like vitamins, minerals can be consumed in toxic quantities (although it is rare). A healthy diet includes most of the minerals your body requires, so supplements and processed foods can add potentially toxic levels of minerals. Table 24.5 and Table 24.6 provide a summary of minerals and their function in the body.
Which hormones work together to control the level of glucose in the blood?	testosterone and insulin	insulin and estrogen	serotonin and glucagon	insulin and glucagon	The pancreas is located near the stomach. Its hormones include insulin and glucagon. These two hormones work together to control the level of glucose in the blood. Insulin causes excess blood glucose to be taken up by the liver, which stores the glucose as glycogen. Glucagon stimulates the liver to break down glycogen into glucose and release it back into the blood. The pancreas also secretes digestive enzymes into the digestive tract.

What year did the soho spacecraft first started to operate?

1987

2012

2006

1996

Humans have sent spacecraft up to study our star. The SOHO spacecraft has been in operation since 1996. The craft orbits the Sun in step with Earth but closer to it. SOHO has sent back amazing images. Onboard instruments have also sent back mountains of data. The data is mostly about the Sun's outer layers.

Concentration of what, the substance left behind when ocean water evaporates, is about 3.5 percent?

quartz

hydrogen

sugar

salts

Dissolved mineral salts wash into the ocean. As ocean water evaporates, it leaves the salts behind. This makes the water saltier. Ocean water is about 3.5 percent salts. The main salt is sodium chloride.

What has a distinct front and back end?

imipenem sphere

hydro sphere

heroclix sphere

volvox sphere

The Volvox sphere has a distinct front and back end. The colony of cells can swim in a coordinated fashion. The cells have eyespots, which are more developed in the cells near the front. This enables the colony to swim towards light.

In how many basic was can substances cross the plasma membrane?

four

one

three

two

If a cell were a house, the plasma membrane would be walls with windows and doors. Moving things in and out of the cell is an important role of the plasma membrane. It controls everything that enters and leaves the cell. There are two basic ways that substances can cross the plasma membrane: passive transport and active transport.

What type of cells have chloroplasts?

human cells

simple cells

animal cells

plant cells

Plants are multicellular eukaryotes with cell walls made of cellulose. Plant cells also have chloroplasts. In addition, plants have specialized reproductive organs. These are structures that produce reproductive cells. Male reproductive organs produce sperm, and female reproductive organs produce eggs. Male and female reproductive organs may be on the same or different plants.

What is the term for disease-causing agents, such as bacteria and viruses?

vaccines

spores

parasites

pathogens

The body’s first line of defense consists of different types of barriers that keep most pathogens out of the body. Pathogens are disease-causing agents, such as bacteria and viruses. These and other types of pathogens are described in Figure below . Regardless of the type of pathogen, however, the first line of defense is always the same.

To figure out the height of a wave you measure the distance between the crest and what?

crater

drift

core

trough

The figure above also shows how the size of waves is measured ( Figure above ). The highest point of a wave is the crest . The lowest point is the trough . The vertical distance between a crest and a trough is the wave height . Wave height is also called amplitude . The horizontal distance between two crests is the wavelength . Both amplitude and wavelength are measures of wave size.

Humans possess greater diversity of what type, compared to laboratory animals?

pathogens

lifespans

elements

genetics

What system can be used by scientists to express very small numbers?

certain diffusion

similar notation

scientific diffusion

scientific notation

Very small numbers can also be expressed using scientific notation. The mass of an electron in decimal notation is 0.000000000000000000000000000911 grams. In scientific notation, the mass is expressed as 9.11 × 10 -28 g. Notice that the value of the exponent is chosen so that the coefficient is between 1 and 10.

An unknown genotype can be determined by observing what, the term for characteristics of the resulting offspring?

chromosonal variations

abnormalities

clusters

phenotypes

Consider the following example: Suppose you have a purple and white flower and purple color ( P ) is dominant to white ( p ). The white flower must be homozygous for the recessive allele, but the genotype of the purple flower is unknown. It could be either PP or Pp . A testcross will determine the organism's genotype. The unknown genotype can be determined by observing the phenotypes of the resulting offspring. If crossing the unknown dominant phenotype ( PP or Pp genotype) individual with the recessive phenotype individual produces only dominant phenotypes (no recessive), then the unknown individual is homozygous dominant. If any recessive phenotypic individuals result from the cross, then the unknown individual must carry the recessive allele, and have the heterozygous genotype.

Wind power, solar power, hydropower, and geothermal power are called renewable sources of energy or what other term?

conservative energy

mandatory energy

specific energy

alternative energy

Alternative energy sources include wind power, solar power, hydropower, and geothermal power.

How much electricity is generated by an average car battery?

six volts

ten volts

eight volts

twelve volts

The description given above describes the process that occurs in one cell of a lead-acid battery. Because cars require a battery with a higher voltage than can be obtained with a single cell, car batteries generally consist of several cells connected together to produce the desired voltage output. A typical car battery will generate twelve volts of electricity.

What is the term for a cellular "scaffolding" that crisscrosses the cytoplasm?

collagen

protoskeleton

cellulose

cytoskeleton

The cytoskeleton is a cellular "scaffolding" or "skeleton" that crisscrosses the cytoplasm. All eukaryotic cells have a cytoskeleton, and recent research has shown that prokaryotic cells also have a cytoskeleton. The eukaryotic cytoskeleton is made up of a network of long, thin protein fibers and has many functions. It helps to maintain cell shape. It holds organelles in place, and for some cells, it enables cell movement. The cytoskeleton also plays important roles in both the intracellular movement of substances and in cell division. Certain proteins act like a path that vesicles and organelles move along within the cell. The threadlike proteins that make up the cytoskeleton continually rebuild to adapt to the cell's constantly changing needs. Three main kinds of cytoskeleton fibers are microtubules, intermediate filaments, and microfilaments.

What common code do all known living organisms use?

code of ethics

biochemical

Morse code

genetic

The genetic code is universal. All known living organisms use the same genetic code. This shows that all organisms share a common evolutionary history.

What are 2 common growth patterns of population?

organic and inorganic

migratory and logistic

exponential and economical

exponential and logistic

Populations may show different patterns of growth. The growth pattern depends partly on the conditions under which a population lives. Two common growth patterns are exponential growth and logistic growth. Both are represented in Figure below .

Solutions to schrödinger’s equation involve four special numbers called what?

light numbers

gravity numbers

linear numbers

quantum numbers

Solutions to Schrödinger’s equation involve four special numbers called quantum numbers . (Three of the numbers, , , and , come from Schrödinger’s equation, and the fourth one comes from an extension of the theory). These four numbers completely describe the energy of an electron. Each electron has exactly four quantum numbers, and no two electrons have the same four numbers. The statement that no two electrons can have the same four quantum numbers is known as the Pauli exclusion principle .

What is the only human cell with flagella?

Feces

egg

saliva

sperm

Sperm cells are the only human cell with flagella . This is because of their need to "swim" long distances to reach an egg for fertilization.

What can be described as a tiny male gametophyte enclosed in a tough capsule?

dna

seed

cell

grain of pollen

A grain of pollen is a tiny male gametophyte enclosed in a tough capsule (see Figure below ). It carries sperm to an ovule while preventing it from drying out. Pollen grains can’t swim, but they are very light, so the wind can carry them. Therefore, they can travel through air instead of water.

What is the largest artery in the body called?

radial

ventricular

carotid

aorta

Flaps of tissue called valves separate the heart’s chambers. Valves keep blood flowing in just one direction through the heart. For example, a valve at the bottom of the right atrium opens to let blood flow from the right atrium to the right ventricle. Then the valve closes so the blood can’t flow back into the right atrium.

Fertilization occurs if a sperm enters the egg while it is passing through what tube?

vaginal

ovarian

Fertilization occurs if a sperm enters the egg while it is passing through the fallopian tube. When this happens, the egg finally completes meiosis. This results in two daughter cells that are different in size. The smaller cell is called a polar body . It contains very little cytoplasm. It soon breaks down and disappears. The larger cell is the egg. It contains most of the cytoplasm. This will develop into a child.

When the smooth muscle relaxes, the arterioles dilate, allowing blood to enter the what?

veins

bones

arteries

capillaries

What to tadpoles develop into?

snakes

toads

mosquitos

frogs

Frogs typically lay their eggs in puddles, ponds, or lakes. Their larvae, or tadpoles , have gills, a tail, but no legs, and need to live in water. If fact, they are quite similar to a fish. Tadpoles develop into adult frogs in water ( Figure below ). During this transformation, they develop lungs, lose their tails and form their four legs.

What part of the body do fish use to absorb oxygen?

under belly

dorsal fin

tail fin

gills

In order to absorb oxygen from the water, fish use gills ( Figure below ). Gills take dissolved oxygen from water as the water flows over the surface of the gill.

The electrons in a water molecule are more concentrated around the more highly charged oxygen nucleus than around this?

peroxide nuclei

helium nuclei

carbon nuclei

hydrogen nuclei

We will find in Atomic Physics that the orbits of electrons are more properly viewed as electron clouds with the density of the cloud related to the probability of finding an electron in that location (as opposed to the definite locations and paths of planets in their orbits around the Sun). This cloud is shifted by the Coulomb force so that the atom on average has a separation of charge. Although the atom remains neutral, it can now be the source of a Coulomb force, since a charge brought near the atom will be closer to one type of charge than the other. Some molecules, such as those of water, have an inherent separation of charge and are thus called polar molecules. Figure ⎛ ⎞ 19.19 illustrates the separation of charge in a water molecule, which has two hydrogen atoms and one oxygen atom ⎝H 2 O⎠ . The water molecule is not symmetric—the hydrogen atoms are repelled to one side, giving the molecule a boomerang shape. The electrons in a water molecule are more concentrated around the more highly charged oxygen nucleus than around the hydrogen nuclei. This makes the oxygen end of the molecule slightly negative and leaves the hydrogen ends slightly positive. The inherent separation of charge in polar molecules makes it easier to align them with external fields and charges. Polar molecules therefore exhibit greater polarization effects and have greater dielectric constants. Those who study chemistry will find that the polar nature of water has many effects. For example, water molecules gather ions much more effectively because they have an electric field and a separation of charge to attract charges of both signs. Also, as brought out in the previous chapter, polar water provides a shield or screening of the electric fields in the highly charged molecules of interest in biological systems.

What is the layer of ground below the surface that is always frozen, even in the summer?

upper crust

tundra

bedrock

permafrost

Polar tundra climates occur near the poles. Tundra climates have permafrost. Permafrost is layer of ground below the surface that is always frozen, even in the summer. Only small plants, such as mosses, can grow in this climate.

What is usually the prey of a protist?

proteins

pathogens

algae

bacteria

The protist wraps around its prey, which is usually bacteria.

What concentrates wave energy or disperses it?

wave reflection

wave diffusion

a prism

wave refraction

Wave refraction either concentrates wave energy or disperses it. In quiet water areas, such as bays, wave energy is dispersed. This allows sand to be deposited. Land that sticks out into the water is eroded by the strong wave energy. The wave energy concentrates its power on the wave-cut cliff .

In plants and algae, photosynthesis takes place in which organelles?

cells

stems

fibroblasts

chloroplasts

In plants and algae, photosynthesis takes place in organelles called chloroplasts. Chloroplasts contain stacks of membranes called thylakoids, which contain chlorophyll. Thylakoids are surrounded by a fluid-filled space called stroma.

What produces sound waves that travel outward in all directions in water?

amplifiers

echo chamber

ultrasound machines

echo sounders

During World War II, battleships and submarines carried echo sounders. Their goal was to locate enemy submarines ( Figure below ). Echo sounders produce sound waves that travel outward in all directions. The sound waves bounce off the nearest object and then return to the ship. Scientists know the speed of sound in seawater. They then can calculate the distance to the object that the sound wave hit. Most of these sound waves did not hit submarines. They instead were used to map the ocean floor.

The roots of a plant take in nutrients and what vital substance?

Soil

air

Ash

water

Carbon fixation is the first step of what cycle involving light reactions?

water cycle

sun cycle

life cycle

calvin cycle

As Melvin Calvin discovered, carbon fixation is the first step of a cycle. Like an electron transport chain, the Calvin Cycle, shown in Figure below , transfers energy in small, controlled steps. Each step pushes molecules uphill in terms of energy content. Recall that in the electron transfer chain, excited electrons lose energy to NADPH and ATP. In the Calvin Cycle, NADPH and ATP formed in the light reactions lose their stored chemical energy to build glucose.

What are the attractive forces that occur between polar molecules called?

ion-dipole forces

induced-dipole forces

particle - dipole forces

dipole-dipole forces

Dipole-dipole forces are the attractive forces that occur between polar molecules. A molecule of hydrogen chloride has a partially positive hydrogen atom and a partially negative chlorine atom. In a collection of many hydrogen chloride molecules, they will align themselves so that the oppositely charged regions of neighboring molecules are near each other.

The production of multiple copies of a single gene is called?

gene change

cell cloning

gene variation

gene cloning

Fossil fuels are made out of what two objects?

soil and animals

gases and animals

plants and water

plants and animals

Fossil fuels are made from plants and animals that lived hundreds of millions of years ago. The plants and animals died. Their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels.

Amoebas and paramecia are examples of what?

protists

vertebrates

bacteria

protozoa

Examples of protozoa include amoebas and paramecia.

Name the bacteria that make food through photosynthesis and release oxygen into the air?

algae

fusobacteria

phytoplankton

cyanobacteria

Bacteria called cyanobacteria are very important. They are bluish green in color (see Figure below ) because they contain chlorophyll (but not chloroplasts, of course). They make food through photosynthesis and release oxygen into the air. These bacteria were probably responsible for adding oxygen to the air on early Earth. This changed the planet’s atmosphere. It also changed the direction of evolution. Ancient cyanobacteria also may have evolved into the chloroplasts of plant cells.

What simple machine consists of a bar that rotates around a fixed point called the fulcrum?

catapult

battering ram

rotor

lever

A lever is a simple machine that consists of a bar that rotates around a fixed point called the fulcrum. There are three classes of levers. Depending on its class, a lever may have an ideal mechanical advantage that is less than, equal to, or greater than 1. First-class levers also change the direction of the input force.

Which carbohydrate is produced by photosynthesis?

sugar

protein

insulin

glucose

Glucose is the carbohydrate produced by photosynthesis. Energy-rich glucose is delivered through your blood to each of your cells.

What term is used to describe the line of latitude right in the middle of the planet?

pole

Prime Meridian

orbital

equator

Lines of latitude circle around Earth. The equator is a line of latitude right in the middle of the planet. The equator is an equal distance from both the North and South Pole. If you know your latitude, you know how far you are north or south of the equator.

What is the opening formed between adjacent vertebrae for the exit of a spinal nerve called?

spinous process

inferior vertebral notch

sympathetic ganglion

intervertebral foramen

Figure 7.24 Intervertebral Disc The bodies of adjacent vertebrae are separated and united by an intervertebral disc, which provides padding and allows for movements between adjacent vertebrae. The disc consists of a fibrous outer layer called the anulus fibrosus and a gel-like center called the nucleus pulposus. The intervertebral foramen is the opening formed between adjacent vertebrae for the exit of a spinal nerve.

What two planets is the asteroid belt found between?

saturn and uranus

mars and venus

earth and venus

mars and jupiter

Hundreds of thousands of asteroids have been found in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month! The majority are located in between the orbits of Mars and Jupiter. This region is called the asteroid belt , as shown in Figure below . There are many thousands of asteroids in the asteroid belt. Still, their total mass adds up to only about 4 percent of Earth’s Moon.

Neon is an example of what kind of gas?

natural

ideal

inert

noble

Once we reach neon, a noble gas, all of the 2p orbitals will be completely full. Neon has a configuration of 1s 2 2s 2 2p 6 . Any further electrons will need to go in the next highest energy orbital, which would be the 3s orbital.

Many organisms look very similar to other organisms because they may be from the same what?

parasites

nutrients

area

species

What type of compound is hydrogen chloride?

ionic

polar

metal

covalent

The largest, most complex covalent molecules have thousands of atoms. Examples include proteins and carbohydrates, which are compounds in living things. The smallest, simplest covalent compounds have molecules with just two atoms. An example is hydrogen chloride (HCl). It consists of one hydrogen atom and one chlorine atom, as you can see in the Figure below . You can watch an animation of hydrogen chloride forming at the following URL.

What kind of volcanic eruptions are less deadly?

explosive

non-dormant

serial eruptions

non-explosive

Some volcanic eruptions are non-explosive ( Figure below ). This happens when there is little or no gas. The lava is thin, fluid and runny. It flows over the ground like a river. People generally have a lot of warning before a lava flow like this reaches them, so non-explosive eruptions are much less deadly. They may still be destructive to property, though. Even when we know that a lava flow is approaching, there are few ways of stopping it!.

Where do most ecosystems get their energy from?

water

earth

heat

sun

Most ecosystems get their energy from the Sun. Only producers can use sunlight to make usable energy. Producers convert the sunlight into chemical energy or food. Consumers get some of that energy when they eat producers. They also pass some of the energy on to other consumers when they are eaten. In this way, energy flows from one living thing to another.

When a solute dissolves into a solvent what is that called?

mixing

solubility

viscosity

enthalpy

Enthalpy changes also occur when a solute undergoes the physical process of dissolving into a solvent. Hot packs and cold packs (see Figure below ) use this property. Many hot packs use calcium chloride, which releases heat when it dissolves according to the equation below.

The smallest part of an element that maintains the identity of that element is called what?

neutron

lattice

nucleus

atom

Note Sometimes the word pure is added to substance, but this is not absolutely necessary. By definition, any single substance is pure. The smallest part of an element that maintains the identity of that element is called an atom. Atoms are extremely tiny; to make a line 1 inch long, you would need 217 million iron atoms. The smallest part of a compound that maintains the identity of that compound is called a molecule. Molecules are composed of atoms that are attached together and behave as a unit. Scientists usually work with millions and millions of atoms and molecules at a time. When a scientist is working with large numbers of atoms or molecules at a time, the scientist is studying the macroscopic view of the universe. However, scientists can also describe chemical events on the level of individual atoms or molecules, which is referred to as the microscopic viewpoint. We will see examples of Saylor URL: http://www. saylor. org/books.

Varves form in lakes covered by what?

soot

coral reef

bridges

ice

Varves form in lakes covered by ice. Varves are useful to scientists for understanding climate.

Speed takes distance and what else into account?

energy

gravity

matter

time

Speed just takes distance and time into account. How might direction be considered as well?.

Which division of the autonomic nervous system controls processes like digestion, heartbeat, and breathing?

dopaminergic

endocrine

synaptic

parasympathetic

The parasympathetic division controls internal organs and glands during the rest of the time. It controls processes like digestion, heartbeat, and breathing when there is not an emergency.

What does the ovule develop into after fertilization?

germ

pollen

zygote

seed

An ovule is a female reproductive structure in seed plants. It contains a tiny female gametophyte. The gametophyte produces an egg cell. After the egg is fertilized by sperm, the ovule develops into a seed.

What is a key factor in the growth of populations?

assimilation

legislation

gentrification

immigration

Moving into an area, or immigration, is a key factor in the growth of populations. Shown above is actual vintage luggage left by some of the millions of immigrants who came through Ellis Island and into the United States.

Air is said to reach what point, a term used by meteorologists, when humidity increases or temperature decreases?

freezing point

bubble point

its dip point

its dew point

Air reaches its dew point when humidity increases or temperature decreases.

In neurons, what often involves gated sodium channels?

polarization

fermentation

excitation

depolarization

Line graphs are especially useful for showing changes over what?

velocity

space

energy

time

Line graphs are especially useful for showing changes over time. The line graph in Figure below shows how distance from school changed over time when some students went on a class trip.

After a massive eruption what will a mountain collapsing above an empty chamber create?

valley

crater

cavern

caldera

During a massive eruption all of the material may be ejected from a magma changer. Without support, the mountain above the empty chamber may collapse. This produces a huge caldera . Calderas are generally round, bowl-shaped formations like the picture in Figure below .

The posterior half of the foot is formed by seven tarsal bones. the most superior of these bones is called?

calcareous

metatarsal

patella

talus

Tarsal Bones The posterior half of the foot is formed by seven tarsal bones (Figure 8.19). The most superior bone is the talus. This has a relatively square-shaped, upper surface that articulates with the tibia and fibula to form the ankle joint. Three areas of articulation form the ankle joint: The superomedial surface of the talus bone articulates with the medial malleolus of the tibia, the top of the talus articulates with the distal end of the tibia, and the lateral side of the talus articulates with the lateral malleolus of the fibula. Inferiorly, the talus articulates with the calcaneus (heel bone), the largest bone of the foot, which forms the heel. Body weight is transferred from the tibia to the talus to the calcaneus, which rests on the ground. The medial calcaneus has a prominent bony extension called the sustentaculum tali (“support for the talus”) that supports the medial side of the talus bone.

What helps to regulate consciousness, arousal, and sleep states?

cerebral cortex

hypothalamus

hippocampus

thalamus

Basal Ganglia Interconnected brain areas called the basal ganglia (or basal nuclei), shown in Figure 35.20b, play important roles in movement control and posture. Damage to the basal ganglia, as in Parkinson’s disease, leads to motor impairments like a shuffling gait when walking. The basal ganglia also regulate motivation. For example, when a wasp sting led to bilateral basal ganglia damage in a 25-year-old businessman, he began to spend all his days in bed and showed no interest in anything or anybody. But when he was externally stimulated—as when someone asked to play a card game with him—he was able to function normally. Interestingly, he and other similar patients do not report feeling bored or frustrated by their state. Thalamus The thalamus (Greek for “inner chamber”), illustrated in Figure 35.24, acts as a gateway to and from the cortex. It receives sensory and motor inputs from the body and also receives feedback from the cortex. This feedback mechanism can modulate conscious awareness of sensory and motor inputs depending on the attention and arousal state of the animal. The thalamus helps regulate consciousness, arousal, and sleep states. A rare genetic disorder called fatal familial insomnia causes the degeneration of thalamic neurons and glia. This disorder prevents affected patients from being able to sleep, among other symptoms, and is eventually fatal.

Some fish will be over-fished to the point that their species ceases to exist, which is also known as what?

abundance

endangered

accumulation

extinction

will inevitably make it more difficult and costly to grow food. The world’s growing human population faces significant challenges in the increasing costs and other difficulties associated with producing food. Wild Food Sources In addition to growing crops and raising food animals, humans obtain food resources from wild populations, primarily wild fish populations. For about one billion people, aquatic resources provide the main source of animal protein. But since 1990, production from global fisheries has declined. Despite considerable effort, few fisheries on Earth are managed sustainability. Fishery extinctions rarely lead to complete extinction of the harvested species, but rather to a radical restructuring of the marine ecosystem in which a dominant species is so over-harvested that it becomes a minor player, ecologically. In addition to humans losing the food source, these alterations affect many other species in ways that are difficult or impossible to predict. The collapse of fisheries has dramatic and long-lasting effects on local human populations that work in the fishery. In addition, the loss of an inexpensive protein source to populations that cannot afford to replace it will increase the cost of living and limit societies in other ways. In general, the fish taken from fisheries have shifted to smaller species and the larger species are overfished. The ultimate outcome could clearly be the loss of aquatic systems as food sources.

Not surprisingly, what is the function of the most developed part of a bird's brain?

controlling thought

controlling digestion

controlling breeding

controlling flight

Birds have a large brain relative to the size of their body. Not surprisingly, the part of the brain that controls flight is the most developed part. The large brain size of birds is also reflected by their high level of intelligence and complex behavior. In fact, birds such as crows and ravens may be more intelligent than many mammals. They are smart enough to use objects such as twigs for tools. They also demonstrate planning and cooperation. Most birds have a poor sense of smell, but they make up for it with their excellent sense of sight. Predatory birds have especially good eyesight. Hawks, for example, have vision that is eight times sharper than human vision.

What type of roots enable a plant to grow on another plant?

mites

Sickness

endemic

epiphytic

Epiphytic roots enable a plant to grow on another plant. For example, the epiphytic roots of orchids develop a spongy tissue to absorb moisture. The banyan tree (Ficus sp. ) begins as an epiphyte, germinating in the branches of a host tree; aerial roots develop from the branches and eventually reach the ground, providing additional support (Figure 30.20). In screwpine (Pandanus sp. ), a palm-like tree that grows in sandy tropical soils, aboveground prop roots develop from the nodes to provide additional support.

What is the distance north or south of the equator called?

elevation

longitude

circumference

latitude

Latitude is the distance north or south of the Equator. It is expressed as a number between 0° and 90° north or south.

In response to a cut, mast cells secrete histamines that cause nearby capillaries to do what?

constrict

harden

narrow

dilate

Figure 42.5 In response to a cut, mast cells secrete histamines that cause nearby capillaries to dilate. Neutrophils and monocytes leave the capillaries. Monocytes mature into macrophages. Neutrophils, dendritic cells and macrophages release chemicals to stimulate the inflammatory response. Neutrophils and macrophages also consume invading bacteria by phagocytosis.

What is the term for an ionic compound that produces positive hydrogen ions when dissolved in water?

base

hydrocarbon

sulfur

acid

An acid is an ionic compound that produces positive hydrogen ions when dissolved in water. Acids taste sour and turn blue litmus paper red.

The stems of all vascular plants get longer through primary growth. this occurs in primary meristem at the tips and ______ of the stems.

layers

edges

bottoms

nodes

The stems of all vascular plants get longer through primary growth. This occurs in primary meristem at the tips and nodes of the stems. Most stems also grow in thickness through secondary growth. This occurs in secondary meristem, which is located in and around the vascular tissues. Secondary growth forms secondary vascular tissues and bark. In many trees, the yearly growth of new vascular tissues results in an annual growth ring like the one in Figure below . When a tree is cut down, the rings in the trunk can be counted to estimate the tree’s age.

What kind of waves are electromagnetic waves?

inverse

amplitude

curved

transverse

In this lesson, you learned that electromagnetic waves are transverse waves. Like other transverse waves, electromagnetic waves have certain properties.

What process is involved in the formation of a waterfall, when a stream flows from an area of harder to softer rock?

evaporation

calcification

migration

erosion

Mountain streams may erode waterfalls. A waterfall forms where a stream flows from an area of harder to softer rock ( Figure below ). The water erodes the softer rock faster than the harder rock. This causes the stream bed to drop down, like a step. This creates a waterfall. As erosion continues, the waterfall gradually moves upstream.

Meissner’s corpuscles are not as plentiful in the palms as they are in the what other part of the hand?

cuticles

bones

fingernails

fingertips

Which of the following statements about mechanoreceptors is false? a. Pacini corpuscles are found in both glabrous and hairy skin. Merkel’s disks are abundant on the fingertips and lips. Ruffini endings are encapsulated mechanoreceptors. Meissner’s corpuscles extend into the lower dermis. Meissner’s corpuscles, (shown in Figure 36.6) also known as tactile corpuscles, are found in the upper dermis, but they project into the epidermis. They, too, are found primarily in the glabrous skin on the fingertips and eyelids. They respond to fine touch and pressure, but they also respond to low-frequency vibration or flutter. They are rapidly adapting, fluid-filled, encapsulated neurons with small, well-defined borders and are responsive to fine details. Like Merkel’s disks, Meissner’s corpuscles are not as plentiful in the palms as they are in the fingertips.

What are the two types of earth crust?

amorphous and continental

reflective and continental

micro and continental

oceanic and continental

The crust is less than 1% of Earth by mass. The two types are oceanic crust and continental crust.

What is determined by the energy of the disturbance that causes the wave?

frequency

wavelength

Ohm

wave amplitude

Wave amplitude is determined by the energy of the disturbance that causes the wave. A wave caused by a disturbance with more energy has greater amplitude.

What is made from the minerals in rocks known as bauxite?

coins

glass

titanium

aluminum

Aluminum is made from the minerals in rocks known as bauxite.

What is a defining feature of deformed sedimentary rocks?

not magnetic

not solid

only horizontal

not horizontal

Sedimentary rocks that are not horizontal have been deformed.

Resemblance to other species can serve as protection to what category of species?

consumer

producer

predator

prey

What type of cells make up the epidermis of a leaf?

mesophyll

chloroplasts

endothermic cells

dermal cells

The epidermis of the leaf consists of a single layer of tightly-packed dermal cells. They secrete waxy cuticle to prevent evaporation of water from the leaf. The epidermis has tiny pores called stomata (singular, stoma) that control transpiration and gas exchange with the air. For photosynthesis, stomata must control the transpiration of water vapor and the exchange of carbon dioxide and oxygen. Stomata are flanked by guard cells that swell or shrink by taking in or losing water through osmosis . When they do, they open or close the stomata (see Figure below ).

What carries warm or cold water throughout the world’s oceans?

earth rotation

gravity

pipes

ocean currents

Ocean currents carry warm or cold water throughout the world’s oceans. They help to even out the temperatures in the oceans. This also affects the temperature of the atmosphere and the climate around the world. Currents that are near shore have a direct impact on climate. They may make the climate much colder or warmer. You can see examples of this in Figure below .

What type of resource cannot be replaced as easily as it is consumed?

untapped

biological

renewable

nonrenewable

A nonrenewable resource is one that cannot be replaced as easily as it is consumed. Fossil fuels are an example of nonrenewable resources. They take millions of years to form naturally, and so they cannot be replaced as fast as they are consumed. To take the place of fossil fuel use, alternative energy resources are being developed. These alternative energy sources often utilize renewable resources. The following are examples of sustainable alternative energy resources:.

What substances are involved in most of the chemical reactions that take place in organisms, including digestion?

vitamins

proteins

hormones

enzymes

Enzymes are involved in most of the chemical reactions that take place in organisms. About 4,000 such reactions are known to be catalyzed by enzymes, but the number may be even higher. In animals, an important function of enzymes is to help digest food. Digestive enzymes speed up reactions that break down large molecules of carbohydrates, proteins, and fats into smaller molecules the body can use. Without digestive enzymes, animals would not be able to break down food molecules quickly enough to provide the energy and nutrients they need to survive.

What occurs when the immune system is not working properly?

anemia

allergy

cancer

immunodeficiency

Immunodeficiency occurs when the immune system is not working properly. As a result, it cannot fight off pathogens that a normal immune system would be able to resist. Rarely, the problem is caused by a defective gene. More often, it is acquired during a person’s lifetime. Immunodeficiency may occur for a variety of reasons:.

The force that a magnet exerts on certain materials is called what?

centripetal force

stellar force

velocity force

magnetic force

The force that a magnet exerts on certain materials, including other magnets, is called magnetic force . The force is exerted over a distance and includes forces of attraction and repulsion. North and south poles of two magnets attract each other, while two north poles or two south poles repel each other. A magnet can exert force over a distance because the magnet is surrounded by a magnetic field . In the Figure below , you can see the magnetic field surrounding a bar magnet. Tiny bits of iron, called iron filings, were placed under a sheet of glass. When the magnet was placed on the glass, it attracted the iron filings. The pattern of the iron filings shows the lines of force that make up the magnetic field of the magnet. The concentration of iron filings near the poles indicates that these areas exert the strongest force. You can also see how the magnetic field affects the compasses placed above the magnet. To see an animated magnetic field of a bar magnet, go to this URL: http://micro. magnet. fsu. edu/electromag/java/magneticlines/.

What is applied to a rock to make it bend and flow?

acid

phosphorus

weathering

stress

The amount of stress on a rock may be greater than the rock’s strength. In that case, the rock will change and deform ( Figure below ). Deep within the Earth, the pressure is very great. A rock behaves like a stretched rubber band. When the stress stops, the rock goes back to its original shape. If more stress is applied to the rock, it bends and flows. It does not return to its original shape. Near the surface, if the stress continues, the rock will fracture and break.

What is the function of chloroplasts that are found in plant and algal cells?

glycolysis

mitosis

spermatogenesis

photosynthesis

Actually, almost all organisms obtain their energy from photosynthetic organisms. For example, if a bird eats a caterpillar, then the bird gets the energy that the caterpillar gets from the plants it eats. So the bird indirectly gets energy that began with the glucose formed through photosynthesis. Therefore, the process of photosynthesis is central to sustaining life on Earth. In eukaryotic organisms, photosynthesis occurs in chloroplasts . Only cells with chloroplasts—plant cells and algal (protist) cells—can perform photosynthesis. Animal cells and fungal cells do not have chloroplasts and, therefore, cannot photosynthesize. That is why these organisms, as well as the non-photosynthetic protists, rely on other organisms to obtain their energy. These organisms are heterotrophs.

What passes through the prostate gland immediately inferior to the bladder before passing below the pubic symphysis?

cerebellum

rectum

vagina

urethra

Male Urethra The male urethra passes through the prostate gland immediately inferior to the bladder before passing below the pubic symphysis (see Figure 25.3b). The length of the male urethra varies between men but averages 20 cm in length. It is divided into four regions: the preprostatic urethra, the prostatic urethra, the membranous urethra, and the spongy or penile urethra. The preprostatic urethra is very short and incorporated into the bladder wall. The prostatic urethra passes through the prostate gland. During sexual intercourse, it receives sperm via the ejaculatory ducts and secretions from the seminal vesicles. Paired Cowper’s glands (bulbourethral glands) produce and secrete mucus into the urethra to buffer urethral pH during sexual stimulation. The mucus neutralizes the usually acidic environment and lubricates the urethra, decreasing the resistance to ejaculation. The membranous urethra passes through the deep muscles of the perineum, where it is invested by the overlying urethral sphincters. The spongy urethra exits at the tip (external urethral orifice) of the penis after passing through the corpus spongiosum. Mucous glands are found along much of the length of the urethra and protect the urethra from extremes of urine pH. Innervation is the same in both males and females.

Terrestrial animals lose water by evaporation from their skin and which surfaces?

pulmonary

anaerobic

digestive

respiratory

What color are leukocytes blood cells?

red

blue

black

white

The chemicals that trigger an inflammatory response attract leukocytes to the site of injury or infection. Leukocytes are white blood cells. Their role is to fight infections and get rid of debris. Leukocytes may respond with either a nonspecific or a specific defense.

What is something that all machines must overcome?

temperature

stress

work

friction

The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat greater than the actual mechanical advantage of the machine as it is used in the real world.

The conservation of momentum principle can be applied to systems as different as a comet striking earth and a gas containing huge numbers of atoms and these?

protons

particles

ions

molecules

The conservation of momentum principle can be applied to systems as different as a comet striking Earth and a gas containing huge numbers of atoms and molecules. Conservation of momentum is violated only when the net external force is not zero. But another larger system can always be considered in which momentum is conserved by simply including the source of the external force. For example, in the collision of two cars considered above, the two-car system conserves momentum while each one-car system does not. Making Connections: Take-Home Investigation—Drop of Tennis Ball and a Basketball Hold a tennis ball side by side and in contact with a basketball. Drop the balls together. (Be careful!) What happens? Explain your observations. Now hold the tennis ball above and in contact with the basketball. What happened? Explain your observations. What do you think will happen if the basketball ball is held above and in contact with the tennis ball?.

What are the small units that comprise nucleic acids?

chromosomes

genes

filaments

nucleotides

DNA and RNA are nucleic acids. Nucleic acids are built of small units called nucleotides.

Minerals that are not pure elements are made of what?

metalloids

isotopes

noble gases

chemical compounds

Minerals that are not pure elements are made of chemical compounds. For example, the mineral quartz is made of the compound silicon dioxide, or SiO 2 . This compound has one atom of the element silicon for every two atoms of the element oxygen.

What can be classified as monoprotic or polyprotic based on the number of acidic hydrogens they contain?

salts

ions

cations

acids

Acids can be classified as monoprotic or polyprotic based on the number of acidic hydrogens they contain.

What is the top part of water able to receive enough sunlight for photosynthesis called?

fantasmic zone

thymic zone

synthesis zone

photic zone

Only the top 200 meters or so of water receive enough sunlight for photosynthesis. This part of the water is called the photic zone. Below 200 meters, there is too little sunlight for photosynthesis to take place. This part of the water is called the aphotic zone. In this zone, food must come from other sources. It may be made by chemosynthesis, in which microorganisms use energy in chemicals instead of sunlight to make food. Or, food may drift down from the water above.

Different media affect what property of light?

temperature

density

color

speed

The speed of light is different in different media.

Signals from rods and cones can follow several different pathways in what structure of the eye?

lens

aperture

aqueous humor

retina

What is the term for getting used to something after being consistently exposed to it?

acceptance

modification

dissociation

habituation

One of the simplest ways of learning that occurs in just about all animals is habituation. Habituation means learning to get used to something after being exposed to it repeatedly. It usually involves getting used to something that is frightening or annoying but not dangerous.

What element do nuclear power plants use in fuel rods?

magnesium

plutonium

boron

uranium

Nuclear power plants use uranium in fuel rods. The fuel rods become nuclear waste. Nuclear waste can be dangerous for hundreds of thousands of years.

Where on earth do bacteria live?

blood

skin

water

all environments

Prokaryotes include Bacteria and Archaea. An individual prokaryote consists of a single cell without a nucleus. Bacteria live in virtually all environments on Earth. Archaea live everywhere on Earth, including extreme environments.

What type of waves radiate energy out from an earthquake's focus?

volcanic

Microwaves

abnormal

seismic

Geologists study earthquake waves to “see” Earth's interior. Waves of energy radiate out from an earthquake’s focus. These are called seismic waves ( Figure below ). Seismic waves change speed as they move through different materials. This causes them to bend. Some seismic waves do not travel through liquids or gases. Scientists use all of this information to understand what makes up the Earth’s interior.

What is a popular treatment for kidney failure?

electrolysis

psychotherapy

metastasis

dialysis

Uncontrolled diabetes may damage capillaries of nephrons. As a result, the kidneys lose much of their ability to filter blood. This is called kidney failure . The only cure for kidney failure is a kidney transplant, but it can be treated with dialysis. Dialysis is a medical procedure in which blood is filtered through a machine (see Figure below ).

What is critical for the formation of hemoglobin?

platelets

salts

proteins

iron ions

Minerals Minerals in food are inorganic compounds that work with other nutrients to ensure the body functions properly. Minerals cannot be made in the body; they come from the diet. The amount of minerals in the body is small—only 4 percent of the total body mass—and most of that consists of the minerals that the body requires in moderate quantities: potassium, sodium, calcium, phosphorus, magnesium, and chloride. The most common minerals in the body are calcium and phosphorous, both of which are stored in the skeleton and necessary for the hardening of bones. Most minerals are ionized, and their ionic forms are used in physiological processes throughout the body. Sodium and chloride ions are electrolytes in the blood and extracellular tissues, and iron ions are critical to the formation of hemoglobin. There are additional trace minerals that are still important to the body’s functions, but their required quantities are much lower. Like vitamins, minerals can be consumed in toxic quantities (although it is rare). A healthy diet includes most of the minerals your body requires, so supplements and processed foods can add potentially toxic levels of minerals. Table 24.5 and Table 24.6 provide a summary of minerals and their function in the body.

Which hormones work together to control the level of glucose in the blood?

testosterone and insulin

insulin and estrogen

serotonin and glucagon

insulin and glucagon

The pancreas is located near the stomach. Its hormones include insulin and glucagon. These two hormones work together to control the level of glucose in the blood. Insulin causes excess blood glucose to be taken up by the liver, which stores the glucose as glycogen. Glucagon stimulates the liver to break down glycogen into glucose and release it back into the blood. The pancreas also secretes digestive enzymes into the digestive tract.