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When your body digests food, it breaks down the molecules of nutrients and releases what? | calories | waste materials | gas | energy | Carbohydrates, proteins, and lipids contain energy. When your body digests food, it breaks down the molecules of these nutrients. This releases the energy so your body can use it. |
The first period of the paleozoic era was called what? | ordovician | carboniferous | permian | cambrian | The first period of the Paleozoic Era was the Cambrian. By the beginning of the Paleozoic, organisms evolved shells. Shells could hold their soft tissues together. Shells could protect them from predators and from drying out. Some organisms evolved external skeletons. These are called exoskeletons . Organisms with hard parts also make good fossils. Fossils from the Cambrian are much more abundant than fossils from the Precambrian. |
What is a molecule with two fatty acids and a modified phosphate group attached to a glycerol backbone? | amino acid | carbohydrate | polymer | phospholipid | Figure 3.19 A phospholipid is a molecule with two fatty acids and a modified phosphate group attached to a glycerol backbone. The phosphate may be modified by the addition of charged or polar chemical groups. Two chemical groups that may modify the phosphate, choline and serine, are shown here. Both choline and serine attach to the phosphate group at the position labeled R via the hydroxyl group indicated in green. |
Some women experience cramping and pain before and during what monthly cycle? | deformation | inflammation | reproduction | menstruation | Some women experience cramping and pain before and during menstruation. |
What is the attraction of oppositely charged ions caused by electron transfer called? | solvent bond | covalent bond | velocity bond | ionic bond | The attraction of oppositely charged ions caused by electron transfer is called an ionic bond. |
What process converts the sun's hydrogen nuclei into helium? | combustion | solar fission | nuclear fission | nuclear fusion | Figure 32.19 Nuclear fusion in the Sun converts hydrogen nuclei into helium; fusion occurs primarily at the boundary of the helium core, where temperature is highest and sufficient hydrogen remains. Energy released diffuses slowly to the surface, with the exception of neutrinos, which escape immediately. Energy production remains stable because of negative feedback effects. |
Both solids and liquids hold a definite what? | shape | mass | size | volume | You encounter solids and liquids in many forms in your everyday life. Solids, unlike liquids, hold a definite shape. Both solids and liquids hold a definite volume. However, on a molecular level, these two states of matter are quite different. In this lesson we will introduce some of the properties of liquids and solids that affect your interactions with the substances all around you. |
Because the fields that make up an electromagnetic wave are at right angles to each other and to the direction that the wave travels, an electromagnetic wave is considered what? | stimulation wave | insverse wave | transverse wave | transverse wave | As you can see in Figure above , the electric and magnetic fields that make up an electromagnetic wave occur are at right angles to each other. Both fields are also at right angles to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. |
Which measure indicates the number of electrons in a given sublevel? | coefficients | subscripts | mole | superscripts | There are no forces of attraction or repulsion between gas particles . Attractive forces are responsible for particles of a real gas condensing together to form a liquid. It is assumed that the particles of an ideal gas have no such attractive forces. The motion of each particle is completely independent of the motion of all other particles. |
Because force and electric field are what, they have direction as well as their value? | mass | sensors | neurons | vectors | Force and electric field are vectors and thus have direction as well as their value. |
Acceleration is a vector, and thus has a both a magnitude and what else? | wavelength | temperature | pressure | direction | Acceleration is a vector, and thus has a both a magnitude and direction. Acceleration can be caused by either a change in the magnitude or the direction of the velocity. Instantaneous acceleration a is the acceleration at a specific instant in time. Deceleration is an acceleration with a direction opposite to that of the velocity. |
What is it called when individual organisms work together with one another? | dualism | continuation | competition | cooperation | Bees and other social animals must cooperate to live together successfully. Cooperation means working together with others. Members of the group may cooperate by dividing up tasks, defending each other, and sharing food. The ants in Figure below are sharing food. One ant is transferring food directly from its mouth to the mouth of another colony member. |
How thick is the earth's continental crust, on average? | 25 kilometers | 60 kilometers | 15 kilometers | 35 kilometers | Continental crust is much thicker than oceanic crust. It is 35 kilometers (22 miles) thick on average, but it varies a lot. Continental crust is made up of many different rocks. All three major rock types — igneous, metamorphic, and sedimentary — are found in the crust. On average, continental crust is much less dense (2.7 g/cm3) than oceanic crust. Since it is less dense, it rises higher above the mantle than oceanic crust. |
Which organ has a thick mucus lining that protects the underlying tissue from the action of the digestive juices? | spleen | liver | colon | stomach | functionality of pepsin. Second, the stomach has a thick mucus lining that protects the underlying tissue from the action of the digestive juices. When this mucus lining is ruptured, ulcers can form in the stomach. Ulcers are open wounds in or on an organ caused by bacteria (Helicobacter pylori) when the mucus lining is ruptured and fails to reform. Small Intestine Chyme moves from the stomach to the small intestine. The small intestine is the organ where the digestion of protein, fats, and carbohydrates is completed. The small intestine is a long tube-like organ with a highly folded surface containing fingerlike projections called the villi. The apical surface of each villus has many microscopic projections called microvilli. These structures, illustrated in Figure 34.12, are lined with epithelial cells on the luminal side and allow for the nutrients to be absorbed from the digested food and absorbed into the blood stream on the other side. The villi and microvilli, with their many folds, increase the surface area of the intestine and increase absorption efficiency of the nutrients. Absorbed nutrients in the blood are carried into the hepatic portal vein, which leads to the liver. There, the liver regulates the distribution of nutrients to the rest of the body and removes toxic substances, including drugs, alcohol, and some pathogens. |
What historical event taught people that soil could be lost by plowing and growing crops and encouraged new methods to prevent erosion? | the land bowl | the debris bowl | the flow bowl | the dust bowl | The Dust Bowl taught people that soil could be lost by plowing and growing crops. This led to the development of new ways of farming that help protect the soil. Some of the methods are described in Figure below . |
In what phase is the moon brightly illuminated? | blue moon | crescent | new moon | full moon | The Earth, Moon and Sun are linked together in space. Monthly or daily cycles continually remind us of these links. Every month, you can see the Moon change. This is due to where it is relative to the Sun and Earth. In one phase, the Moon is brightly illuminated - a full moon. In the opposite phase it is completely dark - a new moon. In between, it is partially lit up. When the Moon is in just the right position, it causes an eclipse. The daily tides are another reminder of the Moon and Sun. They are caused by the pull of the Moon and the Sun on the Earth. Tides were discussed in the Oceans chapter. |
What do vectors possess that scalars do not? | magnitude and weight | height and polarity | direction and texture | magnitude and direction | In physics, a quantity, such as mass, length, or speed that is completely specified by its magnitude and has no direction is called a scalar . A vector , on the other hand, is a quantity possessing both magnitude and direction. A vector quantity is typically represented by an arrow-tipped line segment. The length of the line, drawn to scale, represents the magnitude of the quantity. The direction of the arrow indicates the direction of the vector. Not only can vectors be represented graphically, but they can also be added graphically. |
What are the food making factories of plants? | roots | stems | fruits | leaves | |
What does a pollinator pick from its body and carry directly to another plant of the same species? | egg | spore | pathogen | pollen | Wind-blown pollen might land anywhere and be wasted. Another adaptation solved this problem. Plants evolved traits that attract specific animal pollinators . Like the bee in Figure below , a pollinator picks up pollen on its body and carries it directly to another plant of the same species. This greatly increases the chance that fertilization will occur. |
Melting ice cubes and freezing water are examples of change of what? | role | volume | role | state | A: The paper is being cut into smaller pieces, which is changing its size and shape. The ice cubes are turning into a puddle of liquid water because they are melting. This is a change of state. The tablet is disappearing in the glass of water because it is dissolving into particles that are too small to see. The lighthouse is becoming coated with ice as ocean spray freezes on its surface. This is another change of state. |
What is the term for heterotrophs that eat only or mainly animals? | omnivores | parasites | predators | carnivores | All reptiles are heterotrophs, and the majority eats other animals. Heterotrophs that eat only or mainly animals are called carnivores. Large carnivorous reptiles such as crocodilians are the top predators in their ecosystems. They prey on large birds, fish, deer, turtles, and sometimes farm livestock. Their powerful jaws are strong enough to crush bones and turtle shells. Smaller carnivorous reptiles—including tuataras, snakes, and many lizards—are lower-level predators. They prey on small animals such as insects, frogs, birds, and mice. |
How much work is done when a force is applied in a different direction than the direction of movement? | half | full | minimum | none | Laura Guerin. Work is not done when a force is applied in a different direction than the direction of movement . CC BY-NC 3.0. |
The mercury or alcohol in a common glass what changes its volume as the temperature changes? | barometer | calculator | compass | thermometer | Conversion of Temperature Units We use the word temperature to refer to the hotness or coldness of a substance. One way we measure a change in temperature is to use the fact that most substances expand when their temperature increases and contract when their temperature decreases. The mercury or alcohol in a common glass thermometer changes its volume as the temperature changes. Because the volume of the liquid changes more than the volume of the glass, we can see the liquid expand when it gets warmer and contract when it gets cooler. To mark a scale on a thermometer, we need a set of reference values: Two of the most commonly used are the freezing and boiling temperatures of water at a specified atmospheric pressure. On the Celsius scale, 0 °C is defined as the freezing temperature of water and 100 °C as the boiling temperature of water. The space between the two temperatures is divided into 100 equal intervals, which we call degrees. On the Fahrenheit scale, the freezing point of water is defined as 32 °F and the boiling temperature as 212 °F. The space between these two points on a Fahrenheit thermometer is divided into 180 equal parts (degrees). Defining the Celsius and Fahrenheit temperature scales as described in the previous paragraph results in a slightly more complex relationship between temperature values on these two scales than for different units of measure for other properties. Most measurement units for a given property are directly proportional to one another (y = mx). Using familiar length units as one example: ⎞ ⎛ length in feet = ⎝ 1 ft ⎠ × length in inches 12 in. |
What are commonly used to control insect pests, but can have harmful effects on the environment? | Herbicides | toxins | fertilizers | insecticides | Insecticides are commonly used to control insect pests, but they can have harmful effects on the environment. |
The components of what keep their own identity when they combine and can usually be easily separated? | compound | alloy | solution | mixture | The components of a mixture keep their own identity when they combine. Therefore, they usually can be easily separated again. Their different physical properties are used to separate them. For example, oil is less dense than water, so a mixture of oil and water can be separated by letting it stand until the oil floats to the top. Other ways of separating mixtures are shown in Figure below and in the videos below. |
What type of light can mosquitoes see? | spicule | trichina | neon | infared | A: Some animals can see light in the infrared or ultraviolet range of wavelengths. For example, mosquitoes can see infrared light, which is emitted by warm objects. By seeing infrared light, mosquitoes can tell where the warmest, blood-rich areas of the body are located. |
What subject is a way of learning about the natural world that is based on evidence and logic? | geology | evolution | geography | science | Science is a way of learning about the natural world that is based on evidence and logic. |
Chloroplasts are present only in cells of eukaryotes capable of what process? | sexual reproduction | hydrolysis | digestion | photosynthesis | |
Shielding should be used when receiving x-rays to limit exposure to what potentially harmful form of energy? | evaporation | pollution | convection | radiation | To physically limit radiation doses, we use shielding, increase the distance from a source, and limit the time of exposure. Figure 32.10 illustrates how these are used to protect both the patient and the dental technician when an x-ray is taken. Shielding absorbs radiation and can be provided by any material, including sufficient air. The greater the distance from the source, the more the radiation spreads out. The less time a person is exposed to a given source, the smaller is the dose received by the person. Doses from most medical diagnostics have decreased in recent years due to faster films that require less exposure time. |
What is the way animals act either alone or with other animals called? | animal point | animal way | animal lifestyle | animal behavior | Barking, purring, and playing are just some of the ways in which dogs and cats behave. These are examples of animal behaviors. Animal behavior is any way that animals act, either alone or with other animals. |
What three primary colors of light can be distinguished by the human eye? | red, green, yellow | blue, red, orange | yellow, green, blue | red, green, blue | The human eye can distinguish only red, green, and blue light. These three colors are the primary colors of light. All other colors of light can be created by combining the primary colors. Secondary colors of light—cyan, yellow, and magenta—form when two primary colors combine equally. |
Which body system releases hormones that act on target cells to regulate development, growth, energy metabolism, reproduction, and many behaviors? | exocrine system | pituitary | lymphatic | endocrine system | 37.5 | Endocrine Glands By the end of this section, you will be able to: • Describe the role of different glands in the endocrine system • Explain how the different glands work together to maintain homeostasis Both the endocrine and nervous systems use chemical signals to communicate and regulate the body's physiology. The endocrine system releases hormones that act on target cells to regulate development, growth, energy metabolism, reproduction, and many behaviors. The nervous system releases neurotransmitters or neurohormones that regulate neurons, muscle cells, and endocrine cells. Because the neurons can regulate the release of hormones, the nervous and endocrine systems work in a coordinated manner to regulate the body's physiology. |
What is the main difference between eukaryotic and prokaryotic cells? | eukaryotic cells have a cell wall | prokaryotic cells have a nucleus | eukaryotic cells have a flagella | eukaryotic cells have a nucleus | There are two basic types of cells, prokaryotic cells and eukaryotic cells . The main difference between eukaryotic and prokaryotic cells is that eukaryotic cells have a nucleus . The nucleus is where cells store their DNA , which is the genetic material. The nucleus is surrounded by a membrane. Prokaryotic cells do not have a nucleus. Instead, their DNA floats around inside the cell. Organisms with prokaryotic cells are called prokaryotes . All prokaryotes are single-celled (unicellular) organisms. Bacteria and Archaea are the only prokaryotes. Organisms with eukaryotic cells are called eukaryotes . Animals, plants, fungi, and protists are eukaryotes. All multicellular organisms are eukaryotes. Eukaryotes may also be single-celled. |
What forms when cells start to grow out of control? | inflammation | fat | moles | tumor | Cancer of the testes is most common in males aged 15 to 35. It occurs when cells in the testes grow out of control and form a tumor. If found early, cancer of the testes usually can be cured with surgery. |
Organs, vessels, and lymph make up what system? | nervous | digestive | circulatory | lymphatic | The lymphatic system consists of organs, vessels, and lymph. |
Like the marketplace, the metabolic economy is regulated by what basic principle? | industrial and demand | jobs and demand | price and demand | supply and demand | |
As roots grow longer they will always do what? | get thicker | change direction | get larger | grow downward | Roots have primary and secondary meristems for growth in length and width. As roots grow longer, they always grow down into the ground. Even if you turn a plant upside down, its roots will try to grow downward. How do roots “know” which way to grow? How can they tell down from up? Specialized cells in root caps are able to detect gravity. The cells direct meristem in the tips of roots to grow downward toward the center of Earth. This is generally adaptive for land plants. Can you explain why?. |
Which virus causes cold sores? | stilts virus | flu virus | microbes virus | herpes virus | Cold sores are caused by a herpes virus. |
Duplicated chromosomes are composed of two sister what? | nucleotides | karyotypes | eukaryotes | chromatids | Duplicated chromosomes are composed of two sister chromatids. Chromosomes are compacted using a variety of mechanisms during certain stages of the cell cycle. Several classes of protein are involved in the organization and packing of the chromosomal DNA into a highly condensed structure. The condensing complex compacts chromosomes, and the resulting condensed structure is necessary for chromosomal segregation during mitosis. |
What is the name of anything that has mass and takes up space? | depth | solid | carbon | matter | |
The units of time, day and year are based on what? | moon phases | motions of the sun | gravitational waves | motions of earth | |
What is the term for an amount of force pushing against a given area? | resistance | mass | force | pressure | Gas particles are constantly moving and bumping into things, and this creates force. The amount of force pushing against a given area is called pressure. |
What is the region called where an electron is most likely to be found? | the ellipse | the shell | the nucleus | the orbital | Negative electrons are attracted to the positive nucleus. This force of attraction keeps electrons constantly moving around the nucleus. The region where an electron is most likely to be found is called an orbital. |
Many glasses eventually crystallize, rendering them brittle and this? | molten | powdered | soft | opaque | Many glasses eventually crystallize, rendering them brittle and opaque. Modifying agents such as TiO 2 are frequently added to molten glass to reduce their tendency to crystallize. Why does the addition of small amounts of TiO2 stabilize the amorphous structure of glass?. |
What is magnetism produced by an electrical current? | exomagnetism | strong magnetism | hydromagnetism | electromagnetism | Electromagnetism is magnetism produced by an electric current. Current flowing through a wire creates a magnetic field that surrounds the wire in concentric circles. |
A weak and temporary dipole that influences nearby atoms through electrostatic attraction and repulsion is known as what? | an debased dipole | a fused dipole | an incomplete dipole | an instantaneous dipole | The electron cloud of a helium atom contains two electrons, which can normally be expected to be equally distributed spatially around the nucleus. However, at any given moment the electron distribution may be uneven, resulting in an instantaneous dipole. This weak and temporary dipole subsequently influences neighboring helium atoms through electrostatic attraction and repulsion. It induces a dipole on nearby helium atoms (see Figure below ). |
The motion of molecules in a gas is random in magnitude and direction for individual molecules, but a gas of many molecules has a predictable distribution of what, which is called the maxwell-boltzmann distribution? | molecular shape | molecular size | molecular rate | molecular speeds | Distribution of Molecular Speeds The motion of molecules in a gas is random in magnitude and direction for individual molecules, but a gas of many molecules has a predictable distribution of molecular speeds. This distribution is called the Maxwell-Boltzmann distribution, after its originators, who calculated it based on kinetic theory, and has since been confirmed experimentally. (See Figure 13.23. ) The distribution has a long tail, because a few molecules may go several times the rms speed. The most probable speed v p is less than the rms speed. |
What helps the cell continually renew itself? | lymphocytes | vacuole | centrosome | lysosomes | |
One of the fundamental laws of chemistry deals with the fact that we cannot create or destroy what? | stars | time | protein | matter | One of the fundamental laws of chemistry deals with the fact that we cannot (using chemical means) create or destroy matter. When a reaction is run, the number of atoms of each specific type must be the same on both sides of the equation. For some materials, it turns out that one element can combine with a second element in more than one ratio. Carrying out mass ratio calculations helped establish the law of multiple proportions. |
What are the tiny, tube-shaped structures found inside a kidney called? | dendrites | neurons | jejunum | nephrons | There are many blood vessels in the kidneys ( Figure above ). The kidneys remove urea and other wastes from the blood through tiny filtering units called nephrons. Nephrons ( Figure below ) are tiny, tube-shaped structures found inside each kidney. Each kidney has up to a million nephrons. Each nephron collects a small amount of fluid and waste from a small group of capillaries. |
How many sperm does it take to fertilize an egg? | two | ten | five | one | 85 million sperm per day are produced. per testicle. That's 170,000,000 every day. This means that a single male may produce more than a quadrillion (1,000,000,000,000) sperm cells in his lifetime! But it only takes one to fertilize an egg. |
What type of climate is found mostly near the equator? | cool tropical | warm subtropical | hot dessert | warm tropical | Climate is found in zones around the planet. Warm tropical climates are mostly found near the Equator. Glaciers are mostly found nearer the poles. Wegener assumed that these things were true in the ancient past. |
Metabolism is the collection of what that occur in an organism? | mineral reactions | mechanical reactions | growth reactions | chemical reactions | |
What is the arrangement of a t-tubule with the membranes of sr on either side called? | acid | aracnid | orchid | triad | As the membrane depolarizes, another set of ion channels called voltage-gated sodium channels are triggered to open. Sodium ions enter the muscle fiber, and an action potential rapidly spreads (or “fires”) along the entire membrane to initiate excitation-contraction coupling. Things happen very quickly in the world of excitable membranes (just think about how quickly you can snap your fingers as soon as you decide to do it). Immediately following depolarization of the membrane, it repolarizes, re-establishing the negative membrane potential. Meanwhile, the ACh in the synaptic cleft is degraded by the enzyme acetylcholinesterase (AChE) so that the ACh cannot rebind to a receptor and reopen its channel, which would cause unwanted extended muscle excitation and contraction. Propagation of an action potential along the sarcolemma is the excitation portion of excitation-contraction coupling. Recall that this excitation actually triggers the release of calcium ions (Ca++) from its storage in the cell’s SR. For the action potential to reach the membrane of the SR, there are periodic invaginations in the sarcolemma, called T-tubules (“T” stands for “transverse”). You will recall that the diameter of a muscle fiber can be up to 100 μm, so these T-tubules ensure that the membrane can get close to the SR in the sarcoplasm. The arrangement of a T-tubule with the membranes of SR on either side is called a triad (Figure 10.7). The triad surrounds the cylindrical structure called a myofibril, which contains actin and myosin. |
What is the name of the order that salamanders belong to? | platyhelminth | oronthalic | aneuploid | urodela | Salamanders belong to a group of approximately 500 species of amphibians. The order Urodela, containing salamanders and newts, is divided into three suborders:. |
What is the tough tissue that contains collagen? | fiber | membrane | muscle | cartilage | Another distinguishing feature of vertebrates is an endoskeleton made of bone or cartilage. Cartilage is a tough tissue that contains a protein called collagen. Bone is a hard tissue that consists of a collagen matrix, or framework, filled in with minerals such as calcium. Bone is less flexible than cartilage but stronger. An endoskeleton made of bone rather than cartilage allows animals to grow larger and heavier. Bone also provides more protection for soft tissues and internal organs. |
What common ailment is typically caused by tense muscles in the shoulders, head and neck? | pollution | disturbances | fever | headache | A headache is a very common nervous system problem. Headaches may be a symptom of serious diseases, but they are more commonly due to muscle tension. A tension headache occurs when muscles in the shoulders, neck, and head become too tense. This often happens when people are “stressed out. ” Just trying to relax may help relieve this type of headache. Mild pain relievers such as ibuprofen may also help. |
How many watts equals a horse power? | 375 | 695 | 904 | 745 | Sometimes power is measured in a unit called the horsepower. For example, the power of car engines is usually expressed in horsepowers. One horsepower is the amount of work a horse can do in 1 minute. It equals 745 watts of power. Compare the horsepowers in the Figure below to the other Figure below . |
Some microorganisms can digest cellulose, breaking it down into what? | fructose monomers | gluclose polymers | fructose polymers | glucose monomers | |
Where does most geological activity take place? | plate medians | plate buildings | plate waves | plate boundaries | Most geological activity takes place at plate boundaries. This activity includes volcanoes, earthquakes, and mountain building. The activity occurs as plates interact. Giant slabs of lithosphere moving around can create a lot of activity! The features seen at a plate boundary are determined by the direction of plate motion and by the type of crust found at the boundary. |
What can be used to mechanically separate the two elements by attracting the iron filings out of the mixture and leaving the sulfur behind? | graduated cylinder | centrifuge | laser | magnet | When iron filings and sulfur powder are mixed together in any ratio, they form a mixture. No chemical reaction occurs, and both elements retain their individual properties. A magnet can be used to mechanically separate the two elements by attracting the iron filings out of the mixture and leaving the sulfur behind. |
What forms when a solute dissolves in a solvent? | liquid | chemical | gas | solution | A solution forms when a solute dissolves in a solvent. The rate of dissolving is faster with stirring, a higher temperature, or greater surface area. Many solutes are soluble in water because water is polar. |
The enteric nervous system provides intrinsic innervation, and the autonomic nervous system provides this? | autonomic innervation | arise innervation | complex innervation | extrinsic innervation | layers: mucosa, submucosa, muscularis, and serosa. The enteric nervous system provides intrinsic innervation, and the autonomic nervous system provides extrinsic innervation. |
Virtually all aquatic organisms depend directly or indirectly on what for food? | ground beef | prokaryotes | growths | protists | Figure 23.30 Virtually all aquatic organisms depend directly or indirectly on protists for food. (credit “mollusks”: modification of work by Craig Stihler, USFWS; credit “crab”: modification of work by David Berkowitz; credit “dolphin”: modification of work by Mike Baird; credit “fish”: modification of work by Tim Sheerman-Chase; credit “penguin”: modification of work by Aaron Logan). |
Saltwater is a homogeneous mixture, another term for what? | lipid | structure | element | solution | Solution 1. Saltwater acts as if it were a single substance even though it contains two substances—salt and water. Saltwater is a homogeneous mixture, or a solution. Soil is composed of small pieces of a variety of materials, so it is a heterogeneous mixture. Water is a substance; more specifically, because water is composed of hydrogen and oxygen, it is a compound. Oxygen, a substance, is an element. |
What connects the two hemispheres of the brain? | disruption callosum | The brain stem | holy callosum | corpus callosum | The Brain The brain is the part of the central nervous system that is contained in the cranial cavity of the skull. It includes the cerebral cortex, limbic system, basal ganglia, thalamus, hypothalamus, cerebellum, brainstem, and retinas. The outermost part of the brain is a thick piece of nervous system tissue called the cerebral cortex. The cerebral cortex, limbic system, and basal ganglia make up the two cerebral hemispheres. A thick fiber bundle called the corpus callosum (corpus = “body”; callosum = “tough”) connects the two hemispheres. Although there are some brain functions that are localized more to one hemisphere than the other, the functions of the two hemispheres are largely redundant. In fact, sometimes (very rarely) an entire hemisphere is removed to treat severe epilepsy. While patients do suffer some deficits following the surgery, they can have surprisingly few problems, especially when the surgery is performed on children who have very immature nervous systems. In other surgeries to treat severe epilepsy, the corpus callosum is cut instead of removing an entire hemisphere. This causes a condition called split-brain, which gives insights into unique functions of the two hemispheres. For example, when an. |
Cells like a prokaryotic cell, a eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes, but a eukaryotic cell is typically larger than a prokaryotic cell, has a true nucleus (meaning its dna is surrounded by a membrane), and has other membrane-bound organelles that allow for what? | replicating of functions | misuse of functions | scrobipalpa of functions | compartmentalization of functions | 4.3 Eukaryotic Cells Like a prokaryotic cell, a eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes, but a eukaryotic cell is typically larger than a prokaryotic cell, has a true nucleus (meaning its DNA is surrounded by a membrane), and has other membrane-bound organelles that allow for compartmentalization of functions. The plasma membrane is a phospholipid bilayer embedded with proteins. The nucleus’s nucleolus is the site of ribosome assembly. Ribosomes are either found in the cytoplasm or attached to the cytoplasmic side of the plasma membrane or endoplasmic reticulum. They perform protein synthesis. Mitochondria participate in cellular respiration; they are responsible for the majority of ATP produced in the cell. Peroxisomes hydrolyze fatty acids, amino acids, and some toxins. Vesicles and vacuoles are storage and transport compartments. In plant cells, vacuoles also help break down macromolecules. Animal cells also have a centrosome and lysosomes. The centrosome has two bodies perpendicular to each other, the centrioles, and has an unknown purpose in cell division. Lysosomes are the digestive organelles of animal cells. Plant cells and plant-like cells each have a cell wall, chloroplasts, and a central vacuole. The plant cell wall, whose primary component is cellulose, protects the cell, provides structural support, and gives shape to the cell. Photosynthesis takes place in chloroplasts. The central vacuole can expand without having to produce more cytoplasm. |
Colonial organisms were probably one of the first evolutionary steps towards which type of organisms? | fetus | double cellular | mutated | multicellular | Colonial organisms were probably one of the first evolutionary steps towards multicellular organisms. Algae of the genus Volvox are an example of the bridge between colonial organisms and multicellular organisms. Each Volvox , shown in Figure above , is a colonial organism. It is made of up to 50,000 photosynthetic flagellate algae that are grouped together into a hollow sphere. Volvox live in a variety of freshwater habitats, and were first reported by Antonie van Leeuwenhoek in 1700. |
What do you call accumulation of excess water in the tissues? | diuretic | gout | asthma | edema | Fluid Balance: Edema Edema is the accumulation of excess water in the tissues. It is most common in the soft tissues of the extremities. The physiological causes of edema include water leakage from blood capillaries. Edema is almost always caused by an underlying medical condition, by the use of certain therapeutic drugs, by pregnancy, by localized injury, or by an allergic reaction. In the limbs, the symptoms of edema include swelling of the subcutaneous tissues, an increase in the normal size of the limb, and stretched, tight skin. One quick way to check for subcutaneous edema localized in a limb is to press a finger into the suspected area. Edema is likely if the depression persists for several seconds after the finger is removed (which is called “pitting”). Pulmonary edema is excess fluid in the air sacs of the lungs, a common symptom of heart and/or kidney failure. People with pulmonary edema likely will experience difficulty breathing, and they may experience chest pain. Pulmonary edema can be life threatening, because it compromises gas exchange in the lungs, and anyone having symptoms should immediately seek medical care. In pulmonary edema resulting from heart failure, excessive leakage of water occurs because fluids get “backed up” in the pulmonary capillaries of the lungs, when the left ventricle of the heart is unable to pump sufficient blood into the systemic circulation. Because the left side of the heart is unable to pump out its normal volume of blood, the blood in the pulmonary circulation gets “backed up,” starting with the left atrium, then into the pulmonary veins, and then into pulmonary capillaries. The resulting increased hydrostatic pressure within pulmonary capillaries, as blood is still coming in from the pulmonary arteries, causes fluid to be pushed out of them and into lung tissues. Other causes of edema include damage to blood vessels and/or lymphatic vessels, or a decrease in osmotic pressure in chronic and severe liver disease, where the liver is unable to manufacture plasma proteins (Figure 26.9). A decrease in the normal levels of plasma proteins results in a decrease of colloid osmotic pressure (which counterbalances the hydrostatic pressure) in the capillaries. This process causes loss of water from the blood to the surrounding tissues, resulting in edema. |
Transport epithelia that function in maintaining water balance also often function in disposal of what? | organisms wastes | bacteria | absorption wastes | metabolic wastes | |
What is magnetism produced by electricity called? | excitation | electrical attraction | momentum | electromagnetism | Electricity can be used to produce a magnetic field. Magnetism produced by electricity is called electromagnetism. |
What is an area that is saturated with water or covered by water for at least one season of the year? | a valley | a bog | a peat | a wetland | A wetland is an area that is saturated with water or covered by water for at least one season of the year. The water may be freshwater or salt water. Wetlands are extremely important biomes for several reasons:. |
How are bacteria identified and classified? | by there cell count | by there movement | by their color | by their shape | Bacteria are so small that they can only be seen with a microscope. When viewed under the microscope, they have three distinct shapes ( Figure below ). Bacteria can be identified and classified by their shape:. |
What do we call forces that act on the system from outside? | static | material | internal | external | External forces are forces that act on the system from outside. In our previous example, external forces include the force of gravity acting on both cars (because the other part of the force pair, the pull of gravity the Earth experiences coming from the cars, is not included in the system) and the forces of friction between the tires and the road. |
Prostaglandins also help regulate the aggregation of platelets, one step in the formation of what? | cysts | bloats | acne | blood clots | |
Deceleration is the opposite of what? | vibration | stopping | stimulation | acceleration | Discussion The minus sign indicates that acceleration is to the left. This sign is reasonable because the train initially has a positive velocity in this problem, and a negative acceleration would oppose the motion. Again, acceleration is in the same direction as the change in velocity, which is negative here. This acceleration can be called a deceleration because it has a direction opposite to the velocity. |
Each cell and every living thing requires what? | salt | potassium | calcium | energy | All living things need energy. You can often see energy at work in living things. Look at the hummingbird and jellyfish in Figure below . Both of them are obviously using energy. Living things constantly use energy in less obvious ways as well. Inside every cell, all living things need energy to carry out life processes. Life runs on chemical energy. Where does this chemical energy come from?. |
In the human body, what do you call the intersection where the paths for air and food cross.? | esophagus | cloaca | larynx | pharynx | |
Air conditioning systems can incubate certain bacteria and what else? | root | Cancer | wood | mold | Air conditioning systems that can incubate certain bacteria and mold. |
The toothlessness of modern birds, which serves to trim the weight of the head, is an example of what? | variety | mutation | genetic drift | adaptation | |
What are the active transport mechanisms by which molecules enter and leave the cell inside vesicles? | dielectric and exocytosis | endocytosis and oxidation | oxidation and exocytosis | endocytosis and exocytosis | Endocytosis and exocytosis are active transport mechanisms in which large molecules enter and leave the cell inside vesicles. |
Fractures, rickets, and osteoarthritis all affect what part(s) of the body? | animals | fossils | Heart | bones | Despite their hardness and strength, bones can suffer from injury and disease. Bone problems include fractures, osteoarthritis, and rickets. |
Name the closest living relatives of tetrapods? | lumpfishes | shrimp | spinefishes | lungfishes | |
What type of air may get stuck on the windward side of a mountain range? | steady air | brisk air | live air | maritime air | Maritime air may become stuck on the windward side of a mountain range. For this reason it is unable to bring cooler air farther inland. |
Most protists are aquatic organisms and need what kind of environment to survive? | cold | dry | warm | moist | Most protists are aquatic organisms. They need a moist environment to survive. They are found mainly in damp soil, marshes, puddles, lakes, and the ocean. Some protists are free-living organisms. Others are involved in symbiotic relationships. They live in or on other organisms, including humans. |
The help with diffusion comes from special proteins in the membrane known as what? | installation proteins | lazy proteins | navigation proteins | transport proteins | Water and many other substances cannot simply diffuse across a membrane. Hydrophilic molecules, charged ions, and relatively large molecules such as glucose all need help with diffusion. The help comes from special proteins in the membrane known as transport proteins . Diffusion with the help of transport proteins is called facilitated diffusion . There are several types of transport proteins, including channel proteins and carrier proteins. Both are shown in Figure below . |
The extracellular matrix of most animal cells contains abundant amounts of what protein, which helps hold things together? | keratin | actin | elastin | collagen | Extracellular Matrix of Animal Cells Most animal cells release materials into the extracellular space. The primary components of these materials are proteins, and the most abundant protein is collagen. Collagen fibers are interwoven with carbohydrate-containing protein molecules called proteoglycans. Collectively, these materials are called the extracellular matrix (Figure 4.27). Not only does the extracellular matrix hold the cells together to form a tissue, but it also allows the cells within the tissue to communicate with each other. How can this happen?. |
What are two types of lobe finned fish? | moles and lungfish | sharks and piranha | piranha and pike | coelacanths and lungfish | Lobe-fined fish are currently far fewer in number than ray-finned fish. Their fins, like the one shown in Figure above , contain a stump-like appendage of bone and muscle. There are two groups of lobe-finned fish still alive today: coelacanths and lungfish. |
What is the rate of change of velocity called? | speed | transmission | vibration | acceleration | Acceleration is the rate of change of velocity. So in other words, acceleration tells you how quickly the velocity is increasing or decreasing. An acceleration of indicates that the velocity is increasing by in the positive direction every second. |
What is the main organ required for respiration in mammals? | the brain | the diaphragm | the heart | the lungs | Respiration is the process in which gases are exchanged between the body and the outside air. |
Molecules are represented by symbols that all who agree on? | physics | astrologists | geologists | chemists | This passage from a Bach cello suite could be played by any trained musician from any country, because there is agreement as to what the symbols on the page mean. In the same way, molecules are represented using symbols that all chemists agree upon. |
What is the smallest unit of time commonly based on? | minute | hour | millimeter | second | |
Atoms cannot be subdivided, created, or what? | observed | contained | contaminated | destroyed | Atoms cannot be subdivided, created, or destroyed. |
What process changes a liquid to a gas without boiling? | bubbling | absorption | melting | evaporation | Vaporization is easily confused with evaporation, but the two processes are not the same. Evaporation also changes a liquid to a gas, but it doesn’t involve boiling. Instead, evaporation occurs when particles at the surface of a liquid gain enough energy to escape into the air. This happens without the liquid becoming hot enough to boil. |
Every peripheral nerve is connected directly or indirectly to what? | the optimal cord | the functional cord | the umbilical chord | the spinal cord | The blue lines in this drawing represent nerves of the peripheral nervous system. Every peripheral nerve is connected directly or indirectly to the spinal cord. Notice the thick sciatic nerve. It is the longest (and thickest) nerve in the body, running from the lower region of the spinal cord to just above the knee. |
The four phases of mitosis are prophase, metaphase, anaphase and what? | trichina | spirogyra | postphase | telophase | Mitosis occurs in four phases, called prophase, metaphase, anaphase, and telophase. |
Pathogenic prokaryotes usually cause illness by producing what? | organisms | ions | insects | poisons | |
Once cells _______, they can no longer divide | mature | propagate | migrate | differentiate | Most plants continue to grow throughout their lives. Like other multicellular organisms, plants grow through a combination of cell growth and cell division. Cell growth increases cell size, while cell division (mitosis) increases the number of cells. As plant cells grow, they also become specialized into different cell types through cellular differentiation. Once cells differentiate, they can no longer divide. How do plants grow or replace damaged cells after that?. |
Phase labels - and even special conditions - are sometimes included for the substances that are part of what? | carbon equations | solid equations | toxic equations | chemical equations | Many chemical equations also include phase labels for the substances: (s) for solid, (ℓ) for liquid, (g) for gas, and (aq) for aqueous (i. , dissolved in water). Special conditions, such as temperature, may also be listed above the arrow. For example, 2NaHCO. |
Body waves travel through the earth and arrive at seismograms before what? | function waves | sound waves | velocity waves | surface waves | Body waves travel through the Earth and arrive at seismograms before surface waves. |
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