allenai/sciq · Datasets at Hugging Face

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The barrier defenses are not a response to infections, but they are continuously working to protect against a broad range of what?	ecosystems	mates	nutrients	pathogens	environment of the body’s soft tissues. Barrier defenses are part of the body’s most basic defense mechanisms. The barrier defenses are not a response to infections, but they are continuously working to protect against a broad range of pathogens. The different modes of barrier defenses are associated with the external surfaces of the body, where pathogens may try to enter (Table 21.2). The primary barrier to the entrance of microorganisms into the body is the skin. Not only is the skin covered with a layer of dead, keratinized epithelium that is too dry for bacteria in which to grow, but as these cells are continuously sloughed off from the skin, they carry bacteria and other pathogens with them. Additionally, sweat and other skin secretions may lower pH, contain toxic lipids, and physically wash microbes away.
A minority of people on earth use up most of the planet's what, including energy?	water	air	sand	resources	Of course not. A minority of people use most of the world’s energy and other resources. Not only are their needs met, but they have many luxuries. Many other people lack resources. Many don’t have enough to eat or live, with the threat of hunger. Many also do not have safe, clean water. Some people live in crowded, run-down housing. Some people live in mansions.
Groundwater dissolves minerals and carries the ions in a what?	jet stream	mixture	transition	solution	Groundwater dissolves minerals and carries the ions in solution.
What is the area of our universe that isn't stars and galaxies called?	galaxies	nebula	solar systems	dark matter	We see many objects out in space that emit light. We see other objects that emit other types of electromagnetic radiation. The matter we can see is contained in stars. The stars are contained in galaxies. Scientists think that stars and galaxies make up only a small part of the matter in the Universe. The rest of the matter is called dark matter .
What neurotransmitter is associated with the fight-or-flight response?	endorphins	stomach acid	bile	adrenaline	Adrenaline, or epinephrine, is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages, and participates in the fight-or-flight response of the sympathetic nervous system. Adrenaline is produced in the adrenal medulla of the adrenal gland. So how does it effect processes all over the body?.
What do scientists think are the oldest eukaryotes?	prokaryotes	arthropods	fungi	protists	Scientists think that protists are the oldest eukaryotes.
Geologists found that the youngest rocks on the seafloor were where?	seabed floor	early - ocean ridges	late - ocean ridges	mid - ocean ridges	Different seafloor magnetic stripes equal different ages. By using geologic dating techniques, scientists could figure out what these ages are. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest. Scientists were surprised to find that the oldest seafloor is less than 180 million years old. This may seem old, but the oldest continental crust is around 4 billion years old.
The stability of an ecosystem depends on the actions of what, exemplified by mushrooms on a decaying log and bacteria in soil?	aphids	whitefly	fluxes	decomposers	The stability of an ecosystem depends on the actions of the decomposers. Examples of decomposers include mushrooms on a decaying log. Bacteria in the soil are also decomposers. Imagine what would happen if there were no decomposers. Wastes and the remains of dead organisms would pile up and the nutrients within the waste and dead organisms would not be released back into the ecosystem. Producers would not have enough nutrients. The carbon and nitrogen necessary to build organic compounds, and then cells, allowing an organism to grow, would be insufficient. Other nutrients necessary for an organism to function properly would also not be sufficient. Essentially, many organisms could not exist.
Anabolic steroids, a form of the male sex hormone testosterone, are one of the most widely known performance-enhancing drugs. steroids are used to help build what?	brain tissue	bone mass	nervous tissue	muscle mass	Some athletes attempt to boost their performance by using artificial hormones that enhance muscle performance. Anabolic steroids, a form of the male sex hormone testosterone, are one of the most widely known performance-enhancing drugs. Steroids are used to help build muscle mass. Other hormones that are used to enhance athletic performance include erythropoietin, which triggers the production of red blood cells, and human growth hormone, which can help in building muscle mass. Most performance enhancing drugs are illegal for non-medical purposes. They are also banned by national and international governing bodies including the International Olympic Committee, the U. Olympic Committee, the National Collegiate Athletic Association, the Major League Baseball, and the National Football League. The side effects of synthetic hormones are often significant and non-reversible, and in some cases, fatal. Androgens produce several complications such as liver dysfunctions and liver tumors, prostate gland enlargement, difficulty urinating, premature closure of epiphyseal cartilages, testicular atrophy, infertility, and immune system depression. The physiological strain caused by these substances is often greater than what the body can handle, leading to unpredictable and dangerous effects and linking their use to heart attacks, strokes, and impaired cardiac function. Regulation of the Female Reproductive System In females, FSH stimulates development of egg cells, called ova, which develop in structures called follicles. Follicle cells produce the hormone inhibin, which inhibits FSH production. LH also plays a role in the development of ova, induction of ovulation, and stimulation of estradiol and progesterone production by the ovaries, as illustrated in Figure 37.9. Estradiol and progesterone are steroid hormones that prepare the body for pregnancy. Estradiol produces secondary sex characteristics in females, while both estradiol and progesterone regulate the menstrual cycle.
What is the only planet that is known to support life?	Saturn	Venus	Mars	earth	Mars is a lot like Earth. Mars is rocky and has an atmosphere. Mars even has water! But Mars (and Mercury, Venus, the Moon, Jupiter, Saturn, Uranus and Neptune) does not have any evidence of life. Life is what makes Earth unique. It is also part of Earth's dynamic nature. Life is part of many Earth processes. Life is also dynamic in itself. Constantly adapting and evolving, life forms are always changing. Except those that are so well adapted to their environment, they haven't changed in hundreds of millions of years.
Where is food stored?	The esophagus	The gall bladder	The liver	the stomach
The vertebrae are divided into the cervical region, the thoracic region, and which other region?	pelvic region	cylindrical region	central region	lumbar region	7.3 The Vertebral Column The vertebral column forms the neck and back. The vertebral column originally develops as 33 vertebrae, but is eventually reduced to 24 vertebrae, plus the sacrum and coccyx. The vertebrae are divided into the cervical region (C1–C7 vertebrae), the thoracic region (T1–T12 vertebrae), and the lumbar region (L1–L5 vertebrae). The sacrum arises from the fusion of five sacral vertebrae and the coccyx from the fusion of four small coccygeal vertebrae. The vertebral column has four curvatures, the cervical, thoracic, lumbar, and sacrococcygeal curves. The thoracic and sacrococcygeal curves are primary curves retained from the original fetal curvature. The cervical and lumbar curves develop after birth and thus are secondary curves. The cervical curve develops as the infant begins to hold up the head, and the lumbar curve appears with standing and walking. A typical vertebra consists of an enlarged anterior portion called the body, which provides weight-bearing support. Attached posteriorly to the body is a vertebral arch, which surrounds and defines the vertebral foramen for passage of the spinal cord. The vertebral arch consists of the pedicles, which attach to the vertebral body, and the laminae, which come together to form the roof of the arch. Arising from the vertebral arch are the laterally projecting transverse processes and the posteriorly oriented spinous process. The superior articular processes project upward, where they articulate with the downward projecting inferior articular processes of the next higher vertebrae. A typical cervical vertebra has a small body, a bifid (Y-shaped) spinous process, and U-shaped transverse processes with a transverse foramen. In addition to these characteristics, the axis (C2 vertebra) also has the dens projecting upward from.
What was used to measure the distance between the earth and the moon?	ultrasound	telescope	yardstick	laser beam	The development of modern lasers has opened many doors to both research and applications. A laser beam was used to measure the distance from the Earth to the moon. Lasers are important components of CD players. As the image above illustrates, lasers can provide precise focusing of beams to selectively destroy cancer cells in patients. The ability of a laser to focus precisely is due to high-quality crystals that help give rise to the laser beam. A variety of techniques are used to manufacture pure crystals for use in lasers.
Upon entering the vestibular canal, the pressure waves push down on what duct?	the bile	the regrowth	the implant	the cochlear
Water is formed from oxygen and what other element?	lead	calcium	helium	hydrogen	When hydrogen gas is reacted with oxygen gas, water is formed as the product.
What is the period from earth's origin to the beginning of the phanerozoic eon?	anatolian	Paleolithic	Cenozoic	precambrian	For the first 4 billion years of Earth history there is only a little evidence of life. Organisms were tiny and soft and did not fossilize well. But scientists use a variety of ways to figure out what this early life was like. Note that the period from Earth's origin to the beginning of the Phanerozoic is called the Precambrian.
In a displacement graph, the slope of the line is the average what?	time	direction	speed	velocity	Example 2.17 Determining Average Velocity from a Graph of Displacement versus Time: Jet Car Find the average velocity of the car whose position is graphed in Figure 2.47. Strategy The slope of a graph of x vs. t is average velocity, since slope equals rise over run. In this case, rise = change in displacement and run = change in time, so that.
What is the process by which producers use the energy in sunlight to make food?	Leukemogenesis	Embryogenesis	glycolysis	photosynthesis	By far the most common producers use the energy in sunlight to make food. This is called photosynthesis . Producers that photosynthesize include plants and algae. These organisms must live where there is plenty of sunlight.
What is the term for something that limits the growth or development of an organism, population, or process?	variable	controlling factor	stumbling block	limiting factor	In the predator-prey example, one factor limits the growth of the other factor. As the prey population deceases, the predator population is begins to decrease as well. The prey population is a limiting factor. A limiting factor limits the growth or development of an organism, population, or process.
Where is glucose carried in the human body?	the heart	the liver	the brain	the blood	Chemical energy that organisms need comes from food. The nearly universal food for life is the sugar glucose. Glucose is a simple carbohydrate with the chemical formula C 6 H 12 O 6 . The glucose molecule stores chemical energy in a concentrated, stable form. In your body, glucose is the form of energy that is carried in your blood and taken up by each of your trillions of cells.
What are large glaciers that cover a larger area than just a valley?	ice floes	icebergs	glacial continents	ice caps	Ice caps are large glaciers that cover a larger area than just a valley. An ice cap can bury an entire mountain range or region ( Figure below ). Glaciers come off of ice caps into valleys.
What type of reproduction do fungi engage in?	microscopic	sexual	ephemeral	asexual	Through asexual reproduction , new organisms are produced that are genetically identical to the parent. That is, they have exactly the same DNA. Fungi reproduce asexually through three methods:.
What system transports minerals and water in a plant?	flowers	leaves	stamen	roots	Roots absorb water and minerals and transport them to stems. They also anchor and support a plant, and store food. A root system consists of primary and secondary roots. Each root is made of dermal, ground, and vascular tissues. Roots grow in length and width from primary and secondary meristem.
What is the exchange of energy from one part of the universe to another called?	humidity	cold	temperature	heat	Heat is the exchange of energy from one part of the universe to another. Heat and energy have the same units.
If environmental conditions deteriorate, many species can form protective what?	shells	fibers	proteins	cysts
In what subgroup are oligochaetes classified?	reptiles	mammals	insects	polychaetes
The crocodilia order, which includes crocodiles, alligators, caimans, and gharils, is part of what class of animals?	parasites	aquatic	mammals	reptiles	Crocodilia Reptiles in the Crocodilia Order are called crocodilians. They include crocodiles, alligators, caimans, and gharils. They have four sprawling legs that allow them to run surprisingly fast. They have strong jaws and replace their teeth throughout life. Crocodilians have relatively complex brains and greater intelligence than other reptiles. crocodile.
What fluid is most prevalent in your body?	Coolant	cold	liquid	water	Reporting Scientific Work Whether scientific research is basic science or applied science, scientists must share their findings for other researchers to expand and build upon their discoveries. Communication and collaboration within and between sub disciplines of science are key to the advancement of knowledge in science. For this reason, an important aspect of a scientist’s work is disseminating results and communicating with peers. Scientists can share results by presenting them at a scientific meeting or conference, but this approach can reach only the limited few who are present. Instead, most scientists present their results in peer-reviewed articles that are published in scientific journals. Peer-reviewed articles are scientific papers that are reviewed, usually anonymously by a scientist’s colleagues, or peers. These colleagues are qualified individuals, often experts in the same research area, who judge whether or not the scientist’s work is suitable for publication. The process of peer review helps to ensure that the research described in a scientific paper or grant proposal is original, significant, logical, and thorough. Grant proposals, which are requests for research funding, are also subject to peer review. Scientists publish their work so other scientists can reproduce their experiments under similar or different conditions to expand on the findings. The experimental results must be consistent with the findings of other scientists. There are many journals and the popular press that do not use a peer-review system. A large number of online openaccess journals, journals with articles available without cost, are now available many of which use rigorous peer-review systems, but some of which do not. Results of any studies published in these forums without peer review are not reliable and should not form the basis for other scientific work. In one exception, journals may allow a researcher to cite a personal communication from another researcher about unpublished results with the cited author’s permission.
What are negative electrons attracted to?	neutral electrons	hormones	ions	positive protons	Negative electrons are attracted to positive protons, and this electric force keeps electrons moving about the nucleus. The force of attraction between protons and neutrons, called the strong force, holds the nucleus together.
The largest phylum in the animal kingdom, arthropod, is primarily comprised of what?	amphibians	reptiles	mammals	insects	Arthropods are the largest phylum in the animal kingdom. Most arthropods are insects. The phylum also includes spiders, centipedes, and crustaceans. The arthropod body consists of three segments with a hard exoskeleton and jointed appendages. Terrestrial arthropods have adaptations for life on land, such as trachea or book lungs for breathing air. The earliest arthropods were trilobites. The earliest land arthropods were millipedes.
Which country is formed by a hotspot along the mid-atlantic ridge?	Switzerland	finland	norway	iceland	Hotspots may also be active at plate boundaries. This is especially common at mid-ocean ridges. Iceland is formed by a hotspot along the Mid-Atlantic Ridge.
What is an atom or group of bonded atoms that has a positive or negative charge?	a neutron	an photon	an electron	an ion	An ion is an atom or group of bonded atoms that has a positive or negative charge. Ions are formed when an atom gains or loses electrons from its valence shell ( Figure below ). This process causes an imbalance between the number of positively charged protons and negatively charged electrons, so the overall ion will carry a net positive or negative charge.
What type of reproduction produces offspring from a single parent that share the exact same genetic material as the parent?	sexual reproduction	mutation	microscopic reproduction	asexual reproduction	When humans reproduce, there are two parents involved. DNA must be passed from both the mother and father to the child. Humans cannot reproduce with just one parent; humans can only reproduce sexually. But having just one parent is possible in other eukaryotic organisms, including some insects, fish, and reptiles. These organisms can reproduce asexually, meaning the offspring ("children") have a single parent and share the exact same genetic material as the parent. This is very different from reproduction in humans. Bacteria, being a prokaryotic, single-celled organism, must reproduce asexually.
Invertebrates make up what percentage of all animal species?	30 percent	90 percent	50 percent	95 percent	Invertebrates are animals that lack a vertebral column, or backbone. All the phyla in Table above , except the Phylum Chordata, consist only of invertebrates. Even the Phylum Chordata includes some invertebrate taxa. Invertebrates make up about 95 percent of all animal species.
What do monotremes lack though they have hair and produce milk?	tail	nerves	skin	nipples
What is muscle tissue that is attached to the bone called?	epithelial tissue	ligament	cartilage	skeletal tisse	Muscle tissue that is attached to bone is skeletal muscle . Whether you are blinking your eyes or running a marathon, you are using skeletal muscle. Contractions of skeletal muscle are voluntary, or under conscious control. Skeletal muscle is the most common type of muscle in the human body, so it is described in more detail below.
What results from the evaporation of sea water?	oxygen	carbon-di-oxide	reef	salt	In many parts of the world, table salt is obtained from the evaporation of sea water. The heat for the process comes from the sun.
The human body regulates the use and storage of what simple sugar, a major cellular fuel?	secretion	carbohydrate	insulin	glucose
What planet did the voyager 1 spacecraft visit in 1980?	jupiter	venus	mars	saturn	The Voyager 1 spacecraft visited Saturn in 1980. Voyager 2 followed in 1981. These probes sent back detailed pictures of Saturn, its rings, and some of its moons ( Figure below ). From the Voyager data, we learned what Saturn’s rings are made of. They are particles of water and ice with a little bit of dust. There are several gaps in the rings. These gaps were cleared out by moons within the rings. Gravity attracts dust and gas to the moon from the ring. This leaves a gap in the rings. Other gaps in the rings are caused by the competing forces of Saturn and its moons outside the rings.
What is the shortest phase of the sexual response cycle?	resolution phase	sexual stimulation	plateau phase	the orgasm
What is the name of the process by which plants use energy from sunlight to synthesize carbohydrates?	pollination	osmosis	cellular respiration	photosynthesis	Photosynthesis is the process by which plants use energy from sunlight to synthesize carbohydrates.
Animals need plants for food and?	shelter	fuel	reproduction	energy
The product of a wave's wavelength and its frequency is what?	amplitude	trough	velocity	speed	The product of a wave's wavelength (λ) and its frequency (ν), λν, is the speed of the wave. Thus, for electromagnetic radiation in a vacuum: c = 2.998 × 10 8 ms −1 = λν Wavelength and frequency are inversely proportional: As the wavelength increases, the frequency decreases. The inverse proportionality is illustrated in Figure 6.3. This figure also shows the electromagnetic spectrum, the range of all types of electromagnetic radiation. Each of the various colors of visible light has specific frequencies and wavelengths associated with them, and you can see that visible light makes up only a small portion of the electromagnetic spectrum. Because the technologies developed to work in various parts of the electromagnetic spectrum are different, for reasons of convenience and historical legacies, different units are typically used for different parts of the spectrum. For example, radio waves are usually specified as frequencies (typically in units of MHz), while the visible region is usually specified in wavelengths (typically in units of nm or angstroms).
How did lamarck believe species change over time?	ecological of acquired characteristics	became larger	lose of acquired traits	inheritance of acquired characteristics	Jean Baptiste Lamarck (1744–1829) was an important French naturalist. He was one of the first scientists to propose that species change over time. However, Lamarck was wrong about how species change. His idea of the inheritance of acquired characteristics is incorrect. Traits an organism develops during its own life time cannot be passed on to offspring, as Lamarck believed.
Which is larger: the human sperm or the human egg?	human sperm	same size	zygote	human egg	A human sperm is a tiny cell with a tail. A human egg is much larger. Both cells are mature haploid gametes that are capable of fertilization. What process is shown in this photograph?.
What kind of reaction is a reaction in which two or more substances combine to form a single new substance?	chemical reaction	power reaction	compounding reaction	combination reaction	A combination reaction is a reaction in which two or more substances combine to form a single new substance. Combination reactions can also be called synthesis reactions. The general form of a combination reaction is:.
What is beyond the atmosphere?	vacuum	object	air	space	The chapter focuses on the atmosphere. Beyond the atmosphere is space. The next chapter introduces the study of space.
What structure does methane have?	three dimensional oxyhedra	two dimensional oxyhedra	two dimensional tetrahedra	three dimensional tetrahedra	Methane has a three-dimensional, tetrahedral structure.
What is the blastocyst called after implantation?	an produce	trophoblast	an nucleus	an embryo	After implantation occurs, the blastocyst is called an embryo . The embryonic stage lasts through the eighth week following fertilization. During this time, the embryo grows in size and becomes more complex. It develops specialized cells and tissues and starts to form most organs. For an interactive animation of embryonic development, go to this link: http://health. howstuffworks. com/adam-200129. htm .
What rate is generally higher for endotherms than for ectotherms?	reproduction	mortality	respiration	metabolic
What phylum includes snails, squids and clams?	porifera	protozoa	cnidaria	mollusca	Mollusks are mainly aquatic invertebrates in Phylum Mollusca. They include snails, squids, and clams. Mollusks have a coelom and several organ systems. Most also have a shell, head, foot, and radula, which is a feeding organ. Mollusks are either free-living heterotrophs or parasites.
What is the change in a species over time?	transformation	variation	phenomenon	evolution	Scientists do the same thing when they classify , or put into categories, living things. Scientists classify organisms not only by their physical features, but also by how closely related they are. Lions and tigers look like each other more than they look like bears, but are lions and tigers related? Evolutionarily speaking, yes. Evolution is the change in a species over time. Lions and tigers both evolved from a common ancestor. So it turns out that the two cats are actually more closely related to each other than to bears. How an organism looks and how it is related to other organisms determines how it is classified.
What are the largest known proteins?	keratins	actins	hormones	titins	Proteins can differ from one another in the number and sequence (order) of amino acids. It is because of the side chains of the amino acids that proteins with different amino acid sequences have different shapes and different chemical properties. Small proteins can contain just a few hundred amino acids. Yeast proteins average 466 amino acids. The largest known proteins are the titins, found in muscle, which are composed from over 27,000 amino acids.
What term is used to describe the organism that is invaded and often harmed by a pathogen?	parent	guardian	initial	host	Introduction The environment consists of numerous pathogens, which are agents, usually microorganisms, that cause diseases in their hosts. A host is the organism that is invaded and often harmed by a pathogen. Pathogens include bacteria, protists, fungi and other infectious organisms. We are constantly exposed to pathogens in food and water, on surfaces, and in the air. Mammalian immune systems evolved for protection from such pathogens; they are composed of an extremely diverse array of specialized cells and soluble molecules that coordinate a rapid and flexible defense system capable of providing protection from a majority of these disease agents. Components of the immune system constantly search the body for signs of pathogens. When pathogens are found, immune factors are mobilized to the site of an infection. The immune factors identify the nature of the pathogen, strengthen the corresponding cells and molecules to combat it efficiently, and then halt the immune response after the infection is cleared to avoid unnecessary host cell damage. The immune system can remember pathogens to which it has been exposed to create a more efficient response upon re-exposure. This memory can last several decades. Features of the immune system, such as pathogen identification, specific response, amplification, retreat, and remembrance are essential for survival against pathogens. The immune response can be classified as either innate or active. The innate immune response is always present and attempts to defend against all pathogens rather than focusing on specific ones. Conversely, the adaptive immune response stores information about past infections and mounts pathogen-specific defenses.
Untreated botulism is typically fatal because muscles required for breathing fail to contract when the release of what chemical is blocked?	hydrogen	carbon dioxide	monoxide	acetylcholine
The combined magnetic force of the magnetized wire coil and iron bar makes an electromagnet what?	very heavy	very reduced	Very light	very strong	The combined magnetic force of the magnetized wire coil and iron bar makes an electromagnet very strong.
Where do two or more bones of the skeleton meet?	muscle paths	junctures	valves	joints	Joints are places where two or more bones of the skeleton meet. With the help of muscles, joints allow the body to move with relatively little force. Some joints can move more than others.
Lacking a bony endoskeleton, sharks, rays, and ratfish belong to what group of fish?	freshwater fish	invertebrates	crustaceans	cartilaginous	Cartilaginous Fish Cartilaginous fish include sharks, rays, and ratfish. Their endoskeleton is made of cartilage instead of bone. They also lack a swim bladder. However, they have a complete vertebral column and jaws. They also have a relatively big brain. shark.
What process involves the flow of heat from warmer objects to cooler objects?	radiation	activation	convection	conduction	Through the process of conduction, heat flows from warmer objects to cooler objects ( Figure below ). The lower mantle is heated directly by conduction from the core. In conduction , heat is transferred as atoms collide.
What broad category of animals shows adaptations from water-dwelling to land-dweller, including the ability to breathe air and legs to move on land?	herbivores	reptiles	birds	amphibians	Amphibians! In order for water-dwelling animals to adapt to life on land, many new adaptations had to take place. First, they needed to be able to breathe air instead of obtaining oxygen from water. And fins don't work well as legs! They needed to be able to move around well on land.
What term is used to describe the tendency of a mineral to break along certain planes?	erosion	tooth decay	porosis	cleavage	Cleavage is the tendency of a mineral to break along certain planes. When a mineral breaks along a plane, it makes a smooth surface. Minerals with different crystal structures will break or cleave in different ways ( Figure below ). Halite tends to form cubes with smooth surfaces. Mica tends to form sheets. Fluorite can form octahedrons.
What controls earth's magnetosphere?	gravitational field	ionosphere	stratosphere	magnetic field	Earth's magnetosphere is controlled by the magnetic field. The magnetosphere protects the planet from the solar wind . The solar wind is ions that fly from the Sun to Earth very fast. The magnetosphere protects Earth's ozone layer. So life on Earth needs the protection of the magnetosphere.
In humans, pharyngeal slits later develop into what?	long ear	inner ear	outer ear	middle ear	In some chordates, all four traits persist throughout life and serve important functions. However, in many chordates, including humans, all four traits are present only during the embryonic stage. After that, some of the traits disappear or develop into other organs. For example, in humans, pharyngeal slits are present in embryos and later develop into the middle ear.
What phenomenon involves the forcing of a substance into a cell against its concentration gradient?	secondary transport	active absorption	osmosis	primary active transport	During active transport, specialized integral membrane proteins recognize the substance and allows it access. Essentially this process is forcing a ion or molecule to cross the membrane when normally it would not. Moving a substance against its concentration gradient is known as primary active transport , and the proteins involved in it as "pumps". This process uses the energy of ATP. In secondary active transport , energy from an electrochemical gradient is used to transport substances. This process involves pore-forming proteins that form channels through the cell membrane.
What are used as model organisms in molecular biology and genetics?	weather slime molds	electromagnetic slime molds	convergent slime molds	cellular slime molds	Cellular slime molds are used as model organisms in molecular biology and genetics. They may be the key to how multicellular organisms evolved. Can you explain why?.
The bones of the newborn skull are not fully ossified and are separated by large areas called what?	fissures	sutures	pores	fontanelles	Figure 7.33 Newborn Skull The bones of the newborn skull are not fully ossified and are separated by large areas called fontanelles, which are filled with fibrous connective tissue. The fontanelles allow for continued growth of the skull after birth. At the time of birth, the facial bones are small and underdeveloped, and the mastoid process has not yet formed.
With logistic growth, how does population growth start out?	steadily	exponentially	rapidly	slowly	With logistic growth, the population starts out growing slowly, and then the rate of growth increases—but only to a point. The rate of growth tapers off as the population size approaches its carrying capacity. Carrying capacity is the largest population size that can be supported in an area without harming the environment. This type of growth characterizes many populations.
What determines the color of visible light?	molecular wavelength	wavelength speed	wavelength density	exact wavelength	Human beings and other primates also have the ability to see in color. We have special cells inside our eyes that can distinguish different wavelengths of visible light. Visible light is light in the range of wavelengths that the human eye can sense. The exact wavelength of visible light determines its color.
What do eukaryotic cells have that compartmentalize their functions?	cell walls	vacuoles	cytoplasm	internal membranes	6.2 Eukaryotic cells have internal membranes that compartmentalize their functions.
Earth rotates on its axis once each day and revolves around the sun how often?	every other year	once each month	ever 3 years	once each year	Earth rotates on its axis once each day and revolves around the Sun once every year.
What are the two types of fatty acids?	hydrochloric and carboxylic	saturated and biodegradable	saturated and endogenous	saturated and unsaturated	A lipid is an organic compound such as fat or oil. Organisms use lipids to store energy, but lipids have other important roles as well. Lipids consist of repeating units called fatty acids. There are two types of fatty acids: saturated fatty acids and unsaturated fatty acids.
Lipids are available to the body from how many sources?	two	one	five	three	24.3 Lipid Metabolism Lipids are available to the body from three sources. They can be ingested in the diet, stored in the adipose tissue of the body, or synthesized in the liver. Fats ingested in the diet are digested in the small intestine. The triglycerides are broken down into monoglycerides and free fatty acids, then imported across the intestinal mucosa. Once across, the triglycerides are resynthesized and transported to the liver or adipose tissue. Fatty acids are oxidized through fatty acid or β-oxidation into two-carbon acetyl CoA molecules, which can then enter the Krebs cycle to generate ATP. If excess acetyl CoA is created and overloads the capacity of the Krebs cycle, the acetyl CoA can be used to synthesize ketone bodies. When glucose is limited, ketone bodies can be oxidized and used for fuel. Excess acetyl CoA generated from excess glucose or carbohydrate ingestion can be used for fatty acid synthesis or lipogenesis. Acetyl CoA is used to create lipids, triglycerides, steroid hormones, cholesterol, and bile salts. Lipolysis is the breakdown of triglycerides into glycerol and fatty acids, making them easier for the body to process.
What is a silver-colored alkaline earth metal that is even softer than calcium?	lithium	mercury	magnesium	strontium	Strontium is a silver-colored alkaline Earth metal that is even softer than calcium. Strontium compounds are quite common and have a variety of uses—from fireworks to cement to toothpaste. In fireworks, strontium compounds produce deep red explosions. In toothpaste, like the one pictured in the Figure below , the compound strontium chloride reduces tooth sensitivity.
Statoliths are starch-filled plastids that enable plant roots to detect what force?	current	variation	impact	gravity
How does lysozyme destroy bacteria?	by paralyzing them	by antibiotic use	by eating them	by digesting their cell walls	Another barrier is the saliva in the mouth, which is rich in lysozyme—an enzyme that destroys bacteria by digesting their cell walls. The acidic environment of the stomach, which is fatal to many pathogens, is also a barrier. Additionally, the mucus layer of the gastrointestinal tract, respiratory tract, reproductive tract, eyes, ears, and nose traps both microbes and debris, and facilitates their removal. In the case of the upper respiratory tract, ciliated epithelial cells move potentially contaminated mucus upwards to the mouth, where it is then swallowed into the digestive tract, ending up in the harsh acidic environment of the stomach. Considering how often you breathe compared to how often you eat or perform other activities that expose you to pathogens, it is not surprising that multiple barrier mechanisms have evolved to work in concert to protect this vital area.
The primary role of leaves is to collect what?	precipitation	pollen	insects	sunlight	Plants have specialized organs that help them survive and reproduce in a great diversity of habitats. Major organs of most plants include roots, stems, and leaves. Leaves are the keys not only to plant life but to all terrestrial life. The primary role of leaves is to collect sunlight and make food by photosynthesis . Despite the fundamental importance of the work they do, there is great diversity in the leaves of plants. However, given the diversity of habitats in which plants live, it’s not surprising that there is no single best way to collect solar energy for photosynthesis.
Temperature can be defined as the average of what type of energy of the molecules?	potential	magnetic	optical	kinetic	Temperature is the average kinetic energy of the molecules.
What lens shape corrects myopia?	curve	flat	convex	concave	Myopia is corrected with a concave lens, while hyperopia is corrected with a convex lens.
What serves to replace nonreproducing specialized cells as needed in the adult body?	dendritic cells	osteoclast cells	monocyte cells	stem cells
In physics, resistance is opposition to the flow of what?	surface flow	temperature charges	capacitance	electrical charges	In physics, resistance is opposition to the flow of electric charges in an electric current as it travels through matter. The SI unit for resistance is the ohm. Resistance occurs because moving electrons in current bump into atoms of matter. Resistance reduces the amount of electrical energy that is transferred through matter. That’s because some of the electrical energy is absorbed by the atoms and changed to other forms of energy, such as heat. You can see an animation of resistance at the level of atoms and electrons at this URL: http://www. physics. org/explorelink. asp?id=1738&q=electricalresistance&currentpage=1&age=0&knowledge=0&item=3.
What organs are the main organs of the urinary system?	gall bladder	spleen	prostate	kidneys	The kidneys are the main organs of the urinary system.
What phase follows ovulation?	varicose phase	interstitial phase	telophase	luteal phase
What is used to measure blood pressure?	barometer	anemometer	spectrometer	sphygmomanometer	Chemistry in Everyday Life Measuring Blood Pressure Blood pressure is measured using a device called a sphygmomanometer (Greek sphygmos = “pulse”). It consists of an inflatable cuff to restrict blood flow, a manometer to measure the pressure, and a method of determining when blood flow begins and when it becomes impeded (Figure 9.6). Since its invention in 1881, it has been an essential medical device. There are many types of sphygmomanometers: manual ones that require a stethoscope and are used by medical professionals; mercury ones, used when the most accuracy is required; less accurate mechanical ones; and digital ones that can be used with little training but that have limitations. When using a sphygmomanometer, the cuff is placed around the upper arm and inflated until blood flow is completely blocked, then slowly released. As the heart beats, blood forced through the arteries causes a rise in pressure. This rise in pressure at which blood flow begins is the systolic pressure—the peak pressure in the cardiac cycle. When the cuff’s pressure equals the arterial systolic pressure, blood flows past the cuff, creating audible sounds that can be heard using a stethoscope. This is followed by a decrease in pressure as the heart’s ventricles prepare for another beat. As cuff pressure continues to decrease, eventually sound is no longer heard; this is the diastolic pressure—the lowest pressure (resting phase) in the cardiac cycle. Blood pressure units from a sphygmomanometer are in terms of millimeters of mercury (mm Hg).
Are the lungs organs of the excretory system, the respiratory system, or both?	neither	excretory	respiratory	both	The lungs release carbon dioxide into the air. Carbon dioxide is a gaseous waste product of the cells. Wastes are excreted from the body by the excretory system. Therefore, the lungs are organs of the excretory system as well as the respiratory system.
Light has the properties of both a wave and what else?	electron	atom	nucleus	particle	Light has properties of both a wave and a particle.
Hagfishes have a skull made of what?	bone	gelatin	chitin	cartilage
Water molds are commonly found in moist soil and where else?	crust water	methane water	standing water	surface water	Water molds are commonly found in moist soil and surface water. Many water molds are plant pathogens or fish parasites.
What is considered to be a person's entire genetic information?	organism	chromosome	biosphere	genome	A person’s genome is all of his or her genetic information. In other words, the human genome is all the information that makes us human. And unless you have an identical twin, your genome is unique. No one else has a genome just like yours, though all our genomes are similar.
Where does cellular respiration occur?	Golgi apparatus	nucleus	chloroplasts	mitochondria	Yes. Photosynthesis occurs in the chloroplasts, whereas cellular respiration occurs in the mitochondria. Photosynthesis makes glucose and oxygen, which are then used as the starting products for cellular respiration. Cellular respiration makes carbon dioxide and water (and ATP), which are the starting products (together with sunlight) for photosynthesis.
What are jellyfish and other cnidarian's stingers called?	phenocrysts	prokaryotes	necrocytes	nematocysts	Cnidarians such as jellyfish have radial symmetry. Flatworms and roundworms, which you will read about next, have bilateral symmetry.
What is tube-shaped and brings urine from the kidneys to the urinary bladder?	fallopian tube	gametophytes	vas deferens	ureters	Ureters are tube-shaped and bring urine from the kidneys to the urinary bladder.
When solvent molecules selectively pass through a membrane from a dilute solution to concentrated solution, what process is occurring?	diffusion	plasmolysis	active transport	osmosis	(a) Two solutions of differing concentrations are placed on either side of a semipermeable membrane. (b) When osmosis occurs, solvent molecules selectively pass through the membrane from the dilute solution to the concentrated solution, diluting it until the two concentrations are the same. The pressure exerted by the different height of the solution on the right is called the osmotic pressure. The osmotic pressure of a solution is easy to calculate:.
Water seeping into the ground is known as?	precipitation	invasion	accumulation	infiltration	Infiltration is the process by which water soaks into the ground. Some of the water may seep deep underground. Some may stay in the soil, where plants can absorb it with their roots.
What body system gets rid of waste?	nervous system	digestive system	Muscular system	excretory system	So what happens to your body's wastes? Obviously, you must get rid of them. This is the job of the excretory system. You remove waste as a gas (carbon dioxide), as a liquid (urine and sweat), and as a solid. Excretion is the process of removing wastes and excess water from the body.
Through what form of energy transfer does the sun's energy travel?	Fusion	solar burst	convection	radiation	Radiation is the transfer of energy by waves. Energy can travel as waves through air or empty space. The Sun's energy travels through space by radiation. After sunlight heats the planet's surface, some heat radiates back into the atmosphere.
What are the only regions of space that electrons can occupy?	inside protons	galaxies	inside nuclei	orbits	Electrons can occupy only certain regions of space, called orbits.
What appears in autumn when cool air moves over a warm lake?	movement fog	misty fog	feature fog	steam fog	Steam fog appears in autumn when cool air moves over a warm lake. Water evaporates from the lake surface. As the water vapor cools, it condenses. The fog appears like steam.
All cells need what for processes like active transport?	oxygen	hydrogen	sunlight	energy	All cells, including both plant and animal cells, need energy for processes such as active transport. How do cells obtain the energy they need?.
In certain populations, some of the chromosomes have become what?	dissolved	elongated	composed	fused
What occurs as a result of the discharge of static electricity?	drought	thunder	clouds	lightning	Zachary Wilson. Lightning is the result of the discharge of static electricity . CC BY-NC 3.0.

The barrier defenses are not a response to infections, but they are continuously working to protect against a broad range of what?

ecosystems

mates

nutrients

pathogens

environment of the body’s soft tissues. Barrier defenses are part of the body’s most basic defense mechanisms. The barrier defenses are not a response to infections, but they are continuously working to protect against a broad range of pathogens. The different modes of barrier defenses are associated with the external surfaces of the body, where pathogens may try to enter (Table 21.2). The primary barrier to the entrance of microorganisms into the body is the skin. Not only is the skin covered with a layer of dead, keratinized epithelium that is too dry for bacteria in which to grow, but as these cells are continuously sloughed off from the skin, they carry bacteria and other pathogens with them. Additionally, sweat and other skin secretions may lower pH, contain toxic lipids, and physically wash microbes away.

A minority of people on earth use up most of the planet's what, including energy?

water

air

sand

resources

Of course not. A minority of people use most of the world’s energy and other resources. Not only are their needs met, but they have many luxuries. Many other people lack resources. Many don’t have enough to eat or live, with the threat of hunger. Many also do not have safe, clean water. Some people live in crowded, run-down housing. Some people live in mansions.

Groundwater dissolves minerals and carries the ions in a what?

jet stream

mixture

transition

solution

Groundwater dissolves minerals and carries the ions in solution.

What is the area of our universe that isn't stars and galaxies called?

galaxies

nebula

solar systems

dark matter

We see many objects out in space that emit light. We see other objects that emit other types of electromagnetic radiation. The matter we can see is contained in stars. The stars are contained in galaxies. Scientists think that stars and galaxies make up only a small part of the matter in the Universe. The rest of the matter is called dark matter .

What neurotransmitter is associated with the fight-or-flight response?

endorphins

stomach acid

bile

adrenaline

Adrenaline, or epinephrine, is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages, and participates in the fight-or-flight response of the sympathetic nervous system. Adrenaline is produced in the adrenal medulla of the adrenal gland. So how does it effect processes all over the body?.

What do scientists think are the oldest eukaryotes?

prokaryotes

arthropods

fungi

protists

Scientists think that protists are the oldest eukaryotes.

Geologists found that the youngest rocks on the seafloor were where?

seabed floor

early - ocean ridges

late - ocean ridges

mid - ocean ridges

Different seafloor magnetic stripes equal different ages. By using geologic dating techniques, scientists could figure out what these ages are. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest. Scientists were surprised to find that the oldest seafloor is less than 180 million years old. This may seem old, but the oldest continental crust is around 4 billion years old.

The stability of an ecosystem depends on the actions of what, exemplified by mushrooms on a decaying log and bacteria in soil?

aphids

whitefly

fluxes

decomposers

The stability of an ecosystem depends on the actions of the decomposers. Examples of decomposers include mushrooms on a decaying log. Bacteria in the soil are also decomposers. Imagine what would happen if there were no decomposers. Wastes and the remains of dead organisms would pile up and the nutrients within the waste and dead organisms would not be released back into the ecosystem. Producers would not have enough nutrients. The carbon and nitrogen necessary to build organic compounds, and then cells, allowing an organism to grow, would be insufficient. Other nutrients necessary for an organism to function properly would also not be sufficient. Essentially, many organisms could not exist.

Anabolic steroids, a form of the male sex hormone testosterone, are one of the most widely known performance-enhancing drugs. steroids are used to help build what?

brain tissue

bone mass

nervous tissue

muscle mass

Some athletes attempt to boost their performance by using artificial hormones that enhance muscle performance. Anabolic steroids, a form of the male sex hormone testosterone, are one of the most widely known performance-enhancing drugs. Steroids are used to help build muscle mass. Other hormones that are used to enhance athletic performance include erythropoietin, which triggers the production of red blood cells, and human growth hormone, which can help in building muscle mass. Most performance enhancing drugs are illegal for non-medical purposes. They are also banned by national and international governing bodies including the International Olympic Committee, the U. Olympic Committee, the National Collegiate Athletic Association, the Major League Baseball, and the National Football League. The side effects of synthetic hormones are often significant and non-reversible, and in some cases, fatal. Androgens produce several complications such as liver dysfunctions and liver tumors, prostate gland enlargement, difficulty urinating, premature closure of epiphyseal cartilages, testicular atrophy, infertility, and immune system depression. The physiological strain caused by these substances is often greater than what the body can handle, leading to unpredictable and dangerous effects and linking their use to heart attacks, strokes, and impaired cardiac function. Regulation of the Female Reproductive System In females, FSH stimulates development of egg cells, called ova, which develop in structures called follicles. Follicle cells produce the hormone inhibin, which inhibits FSH production. LH also plays a role in the development of ova, induction of ovulation, and stimulation of estradiol and progesterone production by the ovaries, as illustrated in Figure 37.9. Estradiol and progesterone are steroid hormones that prepare the body for pregnancy. Estradiol produces secondary sex characteristics in females, while both estradiol and progesterone regulate the menstrual cycle.

What is the only planet that is known to support life?

Saturn

Venus

Mars

earth

Mars is a lot like Earth. Mars is rocky and has an atmosphere. Mars even has water! But Mars (and Mercury, Venus, the Moon, Jupiter, Saturn, Uranus and Neptune) does not have any evidence of life. Life is what makes Earth unique. It is also part of Earth's dynamic nature. Life is part of many Earth processes. Life is also dynamic in itself. Constantly adapting and evolving, life forms are always changing. Except those that are so well adapted to their environment, they haven't changed in hundreds of millions of years.

Where is food stored?

The esophagus

The gall bladder

The liver

the stomach

The vertebrae are divided into the cervical region, the thoracic region, and which other region?

pelvic region

cylindrical region

central region

lumbar region

7.3 The Vertebral Column The vertebral column forms the neck and back. The vertebral column originally develops as 33 vertebrae, but is eventually reduced to 24 vertebrae, plus the sacrum and coccyx. The vertebrae are divided into the cervical region (C1–C7 vertebrae), the thoracic region (T1–T12 vertebrae), and the lumbar region (L1–L5 vertebrae). The sacrum arises from the fusion of five sacral vertebrae and the coccyx from the fusion of four small coccygeal vertebrae. The vertebral column has four curvatures, the cervical, thoracic, lumbar, and sacrococcygeal curves. The thoracic and sacrococcygeal curves are primary curves retained from the original fetal curvature. The cervical and lumbar curves develop after birth and thus are secondary curves. The cervical curve develops as the infant begins to hold up the head, and the lumbar curve appears with standing and walking. A typical vertebra consists of an enlarged anterior portion called the body, which provides weight-bearing support. Attached posteriorly to the body is a vertebral arch, which surrounds and defines the vertebral foramen for passage of the spinal cord. The vertebral arch consists of the pedicles, which attach to the vertebral body, and the laminae, which come together to form the roof of the arch. Arising from the vertebral arch are the laterally projecting transverse processes and the posteriorly oriented spinous process. The superior articular processes project upward, where they articulate with the downward projecting inferior articular processes of the next higher vertebrae. A typical cervical vertebra has a small body, a bifid (Y-shaped) spinous process, and U-shaped transverse processes with a transverse foramen. In addition to these characteristics, the axis (C2 vertebra) also has the dens projecting upward from.

What was used to measure the distance between the earth and the moon?

ultrasound

telescope

yardstick

laser beam

The development of modern lasers has opened many doors to both research and applications. A laser beam was used to measure the distance from the Earth to the moon. Lasers are important components of CD players. As the image above illustrates, lasers can provide precise focusing of beams to selectively destroy cancer cells in patients. The ability of a laser to focus precisely is due to high-quality crystals that help give rise to the laser beam. A variety of techniques are used to manufacture pure crystals for use in lasers.

Upon entering the vestibular canal, the pressure waves push down on what duct?

the bile

the regrowth

the implant

the cochlear

Water is formed from oxygen and what other element?

lead

calcium

helium

hydrogen

When hydrogen gas is reacted with oxygen gas, water is formed as the product.

What is the period from earth's origin to the beginning of the phanerozoic eon?

anatolian

Paleolithic

Cenozoic

precambrian

For the first 4 billion years of Earth history there is only a little evidence of life. Organisms were tiny and soft and did not fossilize well. But scientists use a variety of ways to figure out what this early life was like. Note that the period from Earth's origin to the beginning of the Phanerozoic is called the Precambrian.

In a displacement graph, the slope of the line is the average what?

time

direction

speed

velocity

Example 2.17 Determining Average Velocity from a Graph of Displacement versus Time: Jet Car Find the average velocity of the car whose position is graphed in Figure 2.47. Strategy The slope of a graph of x vs. t is average velocity, since slope equals rise over run. In this case, rise = change in displacement and run = change in time, so that.

What is the process by which producers use the energy in sunlight to make food?

Leukemogenesis

Embryogenesis

glycolysis

photosynthesis

By far the most common producers use the energy in sunlight to make food. This is called photosynthesis . Producers that photosynthesize include plants and algae. These organisms must live where there is plenty of sunlight.

What is the term for something that limits the growth or development of an organism, population, or process?

variable

controlling factor

stumbling block

limiting factor

In the predator-prey example, one factor limits the growth of the other factor. As the prey population deceases, the predator population is begins to decrease as well. The prey population is a limiting factor. A limiting factor limits the growth or development of an organism, population, or process.

Where is glucose carried in the human body?

the heart

the liver

the brain

the blood

Chemical energy that organisms need comes from food. The nearly universal food for life is the sugar glucose. Glucose is a simple carbohydrate with the chemical formula C 6 H 12 O 6 . The glucose molecule stores chemical energy in a concentrated, stable form. In your body, glucose is the form of energy that is carried in your blood and taken up by each of your trillions of cells.

What are large glaciers that cover a larger area than just a valley?

ice floes

icebergs

glacial continents

ice caps

Ice caps are large glaciers that cover a larger area than just a valley. An ice cap can bury an entire mountain range or region ( Figure below ). Glaciers come off of ice caps into valleys.

What type of reproduction do fungi engage in?

microscopic

sexual

ephemeral

asexual

Through asexual reproduction , new organisms are produced that are genetically identical to the parent. That is, they have exactly the same DNA. Fungi reproduce asexually through three methods:.

What system transports minerals and water in a plant?

flowers

leaves

stamen

roots

Roots absorb water and minerals and transport them to stems. They also anchor and support a plant, and store food. A root system consists of primary and secondary roots. Each root is made of dermal, ground, and vascular tissues. Roots grow in length and width from primary and secondary meristem.

What is the exchange of energy from one part of the universe to another called?

humidity

cold

temperature

heat

Heat is the exchange of energy from one part of the universe to another. Heat and energy have the same units.

If environmental conditions deteriorate, many species can form protective what?

shells

fibers

proteins

cysts

In what subgroup are oligochaetes classified?

reptiles

mammals

insects

polychaetes

The crocodilia order, which includes crocodiles, alligators, caimans, and gharils, is part of what class of animals?

parasites

aquatic

mammals

reptiles

Crocodilia Reptiles in the Crocodilia Order are called crocodilians. They include crocodiles, alligators, caimans, and gharils. They have four sprawling legs that allow them to run surprisingly fast. They have strong jaws and replace their teeth throughout life. Crocodilians have relatively complex brains and greater intelligence than other reptiles. crocodile.

What fluid is most prevalent in your body?

Coolant

cold

liquid

water

Reporting Scientific Work Whether scientific research is basic science or applied science, scientists must share their findings for other researchers to expand and build upon their discoveries. Communication and collaboration within and between sub disciplines of science are key to the advancement of knowledge in science. For this reason, an important aspect of a scientist’s work is disseminating results and communicating with peers. Scientists can share results by presenting them at a scientific meeting or conference, but this approach can reach only the limited few who are present. Instead, most scientists present their results in peer-reviewed articles that are published in scientific journals. Peer-reviewed articles are scientific papers that are reviewed, usually anonymously by a scientist’s colleagues, or peers. These colleagues are qualified individuals, often experts in the same research area, who judge whether or not the scientist’s work is suitable for publication. The process of peer review helps to ensure that the research described in a scientific paper or grant proposal is original, significant, logical, and thorough. Grant proposals, which are requests for research funding, are also subject to peer review. Scientists publish their work so other scientists can reproduce their experiments under similar or different conditions to expand on the findings. The experimental results must be consistent with the findings of other scientists. There are many journals and the popular press that do not use a peer-review system. A large number of online openaccess journals, journals with articles available without cost, are now available many of which use rigorous peer-review systems, but some of which do not. Results of any studies published in these forums without peer review are not reliable and should not form the basis for other scientific work. In one exception, journals may allow a researcher to cite a personal communication from another researcher about unpublished results with the cited author’s permission.

What are negative electrons attracted to?

neutral electrons

hormones

ions

positive protons

Negative electrons are attracted to positive protons, and this electric force keeps electrons moving about the nucleus. The force of attraction between protons and neutrons, called the strong force, holds the nucleus together.

The largest phylum in the animal kingdom, arthropod, is primarily comprised of what?

amphibians

reptiles

mammals

insects

Arthropods are the largest phylum in the animal kingdom. Most arthropods are insects. The phylum also includes spiders, centipedes, and crustaceans. The arthropod body consists of three segments with a hard exoskeleton and jointed appendages. Terrestrial arthropods have adaptations for life on land, such as trachea or book lungs for breathing air. The earliest arthropods were trilobites. The earliest land arthropods were millipedes.

Which country is formed by a hotspot along the mid-atlantic ridge?

Switzerland

finland

norway

iceland

Hotspots may also be active at plate boundaries. This is especially common at mid-ocean ridges. Iceland is formed by a hotspot along the Mid-Atlantic Ridge.

What is an atom or group of bonded atoms that has a positive or negative charge?

a neutron

an photon

an electron

an ion

An ion is an atom or group of bonded atoms that has a positive or negative charge. Ions are formed when an atom gains or loses electrons from its valence shell ( Figure below ). This process causes an imbalance between the number of positively charged protons and negatively charged electrons, so the overall ion will carry a net positive or negative charge.

What type of reproduction produces offspring from a single parent that share the exact same genetic material as the parent?

sexual reproduction

mutation

microscopic reproduction

asexual reproduction

When humans reproduce, there are two parents involved. DNA must be passed from both the mother and father to the child. Humans cannot reproduce with just one parent; humans can only reproduce sexually. But having just one parent is possible in other eukaryotic organisms, including some insects, fish, and reptiles. These organisms can reproduce asexually, meaning the offspring ("children") have a single parent and share the exact same genetic material as the parent. This is very different from reproduction in humans. Bacteria, being a prokaryotic, single-celled organism, must reproduce asexually.

Invertebrates make up what percentage of all animal species?

30 percent

90 percent

50 percent

95 percent

Invertebrates are animals that lack a vertebral column, or backbone. All the phyla in Table above , except the Phylum Chordata, consist only of invertebrates. Even the Phylum Chordata includes some invertebrate taxa. Invertebrates make up about 95 percent of all animal species.

What do monotremes lack though they have hair and produce milk?

tail

nerves

skin

nipples

What is muscle tissue that is attached to the bone called?

epithelial tissue

ligament

cartilage

skeletal tisse

Muscle tissue that is attached to bone is skeletal muscle . Whether you are blinking your eyes or running a marathon, you are using skeletal muscle. Contractions of skeletal muscle are voluntary, or under conscious control. Skeletal muscle is the most common type of muscle in the human body, so it is described in more detail below.

What results from the evaporation of sea water?

oxygen

carbon-di-oxide

reef

salt

In many parts of the world, table salt is obtained from the evaporation of sea water. The heat for the process comes from the sun.

The human body regulates the use and storage of what simple sugar, a major cellular fuel?

secretion

carbohydrate

insulin

glucose

What planet did the voyager 1 spacecraft visit in 1980?

jupiter

venus

mars

saturn

The Voyager 1 spacecraft visited Saturn in 1980. Voyager 2 followed in 1981. These probes sent back detailed pictures of Saturn, its rings, and some of its moons ( Figure below ). From the Voyager data, we learned what Saturn’s rings are made of. They are particles of water and ice with a little bit of dust. There are several gaps in the rings. These gaps were cleared out by moons within the rings. Gravity attracts dust and gas to the moon from the ring. This leaves a gap in the rings. Other gaps in the rings are caused by the competing forces of Saturn and its moons outside the rings.

What is the shortest phase of the sexual response cycle?

resolution phase

sexual stimulation

plateau phase

the orgasm

What is the name of the process by which plants use energy from sunlight to synthesize carbohydrates?

pollination

osmosis

cellular respiration

photosynthesis

Photosynthesis is the process by which plants use energy from sunlight to synthesize carbohydrates.

Animals need plants for food and?

shelter

fuel

reproduction

energy

The product of a wave's wavelength and its frequency is what?

amplitude

trough

velocity

speed

The product of a wave's wavelength (λ) and its frequency (ν), λν, is the speed of the wave. Thus, for electromagnetic radiation in a vacuum: c = 2.998 × 10 8 ms −1 = λν Wavelength and frequency are inversely proportional: As the wavelength increases, the frequency decreases. The inverse proportionality is illustrated in Figure 6.3. This figure also shows the electromagnetic spectrum, the range of all types of electromagnetic radiation. Each of the various colors of visible light has specific frequencies and wavelengths associated with them, and you can see that visible light makes up only a small portion of the electromagnetic spectrum. Because the technologies developed to work in various parts of the electromagnetic spectrum are different, for reasons of convenience and historical legacies, different units are typically used for different parts of the spectrum. For example, radio waves are usually specified as frequencies (typically in units of MHz), while the visible region is usually specified in wavelengths (typically in units of nm or angstroms).

How did lamarck believe species change over time?

ecological of acquired characteristics

became larger

lose of acquired traits

inheritance of acquired characteristics

Jean Baptiste Lamarck (1744–1829) was an important French naturalist. He was one of the first scientists to propose that species change over time. However, Lamarck was wrong about how species change. His idea of the inheritance of acquired characteristics is incorrect. Traits an organism develops during its own life time cannot be passed on to offspring, as Lamarck believed.

Which is larger: the human sperm or the human egg?

human sperm

same size

zygote

human egg

A human sperm is a tiny cell with a tail. A human egg is much larger. Both cells are mature haploid gametes that are capable of fertilization. What process is shown in this photograph?.

What kind of reaction is a reaction in which two or more substances combine to form a single new substance?

chemical reaction

power reaction

compounding reaction

combination reaction

A combination reaction is a reaction in which two or more substances combine to form a single new substance. Combination reactions can also be called synthesis reactions. The general form of a combination reaction is:.

What is beyond the atmosphere?

vacuum

object

air

space

The chapter focuses on the atmosphere. Beyond the atmosphere is space. The next chapter introduces the study of space.

What structure does methane have?

three dimensional oxyhedra

two dimensional oxyhedra

two dimensional tetrahedra

three dimensional tetrahedra

Methane has a three-dimensional, tetrahedral structure.

What is the blastocyst called after implantation?

an produce

trophoblast

an nucleus

an embryo

After implantation occurs, the blastocyst is called an embryo . The embryonic stage lasts through the eighth week following fertilization. During this time, the embryo grows in size and becomes more complex. It develops specialized cells and tissues and starts to form most organs. For an interactive animation of embryonic development, go to this link: http://health. howstuffworks. com/adam-200129. htm .

What rate is generally higher for endotherms than for ectotherms?

reproduction

mortality

respiration

metabolic

What phylum includes snails, squids and clams?

porifera

protozoa

cnidaria

mollusca

Mollusks are mainly aquatic invertebrates in Phylum Mollusca. They include snails, squids, and clams. Mollusks have a coelom and several organ systems. Most also have a shell, head, foot, and radula, which is a feeding organ. Mollusks are either free-living heterotrophs or parasites.

What is the change in a species over time?

transformation

variation

phenomenon

evolution

Scientists do the same thing when they classify , or put into categories, living things. Scientists classify organisms not only by their physical features, but also by how closely related they are. Lions and tigers look like each other more than they look like bears, but are lions and tigers related? Evolutionarily speaking, yes. Evolution is the change in a species over time. Lions and tigers both evolved from a common ancestor. So it turns out that the two cats are actually more closely related to each other than to bears. How an organism looks and how it is related to other organisms determines how it is classified.

What are the largest known proteins?

keratins

actins

hormones

titins

Proteins can differ from one another in the number and sequence (order) of amino acids. It is because of the side chains of the amino acids that proteins with different amino acid sequences have different shapes and different chemical properties. Small proteins can contain just a few hundred amino acids. Yeast proteins average 466 amino acids. The largest known proteins are the titins, found in muscle, which are composed from over 27,000 amino acids.

What term is used to describe the organism that is invaded and often harmed by a pathogen?

parent

guardian

initial

host

Introduction The environment consists of numerous pathogens, which are agents, usually microorganisms, that cause diseases in their hosts. A host is the organism that is invaded and often harmed by a pathogen. Pathogens include bacteria, protists, fungi and other infectious organisms. We are constantly exposed to pathogens in food and water, on surfaces, and in the air. Mammalian immune systems evolved for protection from such pathogens; they are composed of an extremely diverse array of specialized cells and soluble molecules that coordinate a rapid and flexible defense system capable of providing protection from a majority of these disease agents. Components of the immune system constantly search the body for signs of pathogens. When pathogens are found, immune factors are mobilized to the site of an infection. The immune factors identify the nature of the pathogen, strengthen the corresponding cells and molecules to combat it efficiently, and then halt the immune response after the infection is cleared to avoid unnecessary host cell damage. The immune system can remember pathogens to which it has been exposed to create a more efficient response upon re-exposure. This memory can last several decades. Features of the immune system, such as pathogen identification, specific response, amplification, retreat, and remembrance are essential for survival against pathogens. The immune response can be classified as either innate or active. The innate immune response is always present and attempts to defend against all pathogens rather than focusing on specific ones. Conversely, the adaptive immune response stores information about past infections and mounts pathogen-specific defenses.

Untreated botulism is typically fatal because muscles required for breathing fail to contract when the release of what chemical is blocked?

hydrogen

carbon dioxide

monoxide

acetylcholine

The combined magnetic force of the magnetized wire coil and iron bar makes an electromagnet what?

very heavy

very reduced

Very light

very strong

The combined magnetic force of the magnetized wire coil and iron bar makes an electromagnet very strong.

Where do two or more bones of the skeleton meet?

muscle paths

junctures

valves

joints

Joints are places where two or more bones of the skeleton meet. With the help of muscles, joints allow the body to move with relatively little force. Some joints can move more than others.

Lacking a bony endoskeleton, sharks, rays, and ratfish belong to what group of fish?

freshwater fish

invertebrates

crustaceans

cartilaginous

Cartilaginous Fish Cartilaginous fish include sharks, rays, and ratfish. Their endoskeleton is made of cartilage instead of bone. They also lack a swim bladder. However, they have a complete vertebral column and jaws. They also have a relatively big brain. shark.

What process involves the flow of heat from warmer objects to cooler objects?

radiation

activation

convection

conduction

Through the process of conduction, heat flows from warmer objects to cooler objects ( Figure below ). The lower mantle is heated directly by conduction from the core. In conduction , heat is transferred as atoms collide.

What broad category of animals shows adaptations from water-dwelling to land-dweller, including the ability to breathe air and legs to move on land?

herbivores

reptiles

birds

amphibians

Amphibians! In order for water-dwelling animals to adapt to life on land, many new adaptations had to take place. First, they needed to be able to breathe air instead of obtaining oxygen from water. And fins don't work well as legs! They needed to be able to move around well on land.

What term is used to describe the tendency of a mineral to break along certain planes?

erosion

tooth decay

porosis

cleavage

Cleavage is the tendency of a mineral to break along certain planes. When a mineral breaks along a plane, it makes a smooth surface. Minerals with different crystal structures will break or cleave in different ways ( Figure below ). Halite tends to form cubes with smooth surfaces. Mica tends to form sheets. Fluorite can form octahedrons.

What controls earth's magnetosphere?

gravitational field

ionosphere

stratosphere

magnetic field

Earth's magnetosphere is controlled by the magnetic field. The magnetosphere protects the planet from the solar wind . The solar wind is ions that fly from the Sun to Earth very fast. The magnetosphere protects Earth's ozone layer. So life on Earth needs the protection of the magnetosphere.

In humans, pharyngeal slits later develop into what?

long ear

inner ear

outer ear

middle ear

In some chordates, all four traits persist throughout life and serve important functions. However, in many chordates, including humans, all four traits are present only during the embryonic stage. After that, some of the traits disappear or develop into other organs. For example, in humans, pharyngeal slits are present in embryos and later develop into the middle ear.

What phenomenon involves the forcing of a substance into a cell against its concentration gradient?

secondary transport

active absorption

osmosis

primary active transport

During active transport, specialized integral membrane proteins recognize the substance and allows it access. Essentially this process is forcing a ion or molecule to cross the membrane when normally it would not. Moving a substance against its concentration gradient is known as primary active transport , and the proteins involved in it as "pumps". This process uses the energy of ATP. In secondary active transport , energy from an electrochemical gradient is used to transport substances. This process involves pore-forming proteins that form channels through the cell membrane.

What are used as model organisms in molecular biology and genetics?

weather slime molds

electromagnetic slime molds

convergent slime molds

cellular slime molds

Cellular slime molds are used as model organisms in molecular biology and genetics. They may be the key to how multicellular organisms evolved. Can you explain why?.

The bones of the newborn skull are not fully ossified and are separated by large areas called what?

fissures

sutures

pores

fontanelles

Figure 7.33 Newborn Skull The bones of the newborn skull are not fully ossified and are separated by large areas called fontanelles, which are filled with fibrous connective tissue. The fontanelles allow for continued growth of the skull after birth. At the time of birth, the facial bones are small and underdeveloped, and the mastoid process has not yet formed.

With logistic growth, how does population growth start out?

steadily

exponentially

rapidly

slowly

With logistic growth, the population starts out growing slowly, and then the rate of growth increases—but only to a point. The rate of growth tapers off as the population size approaches its carrying capacity. Carrying capacity is the largest population size that can be supported in an area without harming the environment. This type of growth characterizes many populations.

What determines the color of visible light?

molecular wavelength

wavelength speed

wavelength density

exact wavelength

Human beings and other primates also have the ability to see in color. We have special cells inside our eyes that can distinguish different wavelengths of visible light. Visible light is light in the range of wavelengths that the human eye can sense. The exact wavelength of visible light determines its color.

What do eukaryotic cells have that compartmentalize their functions?

cell walls

vacuoles

cytoplasm

internal membranes

6.2 Eukaryotic cells have internal membranes that compartmentalize their functions.

Earth rotates on its axis once each day and revolves around the sun how often?

every other year

once each month

ever 3 years

once each year

Earth rotates on its axis once each day and revolves around the Sun once every year.

What are the two types of fatty acids?

hydrochloric and carboxylic

saturated and biodegradable

saturated and endogenous

saturated and unsaturated

A lipid is an organic compound such as fat or oil. Organisms use lipids to store energy, but lipids have other important roles as well. Lipids consist of repeating units called fatty acids. There are two types of fatty acids: saturated fatty acids and unsaturated fatty acids.

Lipids are available to the body from how many sources?

two

one

five

three

24.3 Lipid Metabolism Lipids are available to the body from three sources. They can be ingested in the diet, stored in the adipose tissue of the body, or synthesized in the liver. Fats ingested in the diet are digested in the small intestine. The triglycerides are broken down into monoglycerides and free fatty acids, then imported across the intestinal mucosa. Once across, the triglycerides are resynthesized and transported to the liver or adipose tissue. Fatty acids are oxidized through fatty acid or β-oxidation into two-carbon acetyl CoA molecules, which can then enter the Krebs cycle to generate ATP. If excess acetyl CoA is created and overloads the capacity of the Krebs cycle, the acetyl CoA can be used to synthesize ketone bodies. When glucose is limited, ketone bodies can be oxidized and used for fuel. Excess acetyl CoA generated from excess glucose or carbohydrate ingestion can be used for fatty acid synthesis or lipogenesis. Acetyl CoA is used to create lipids, triglycerides, steroid hormones, cholesterol, and bile salts. Lipolysis is the breakdown of triglycerides into glycerol and fatty acids, making them easier for the body to process.

What is a silver-colored alkaline earth metal that is even softer than calcium?

lithium

mercury

magnesium

strontium

Strontium is a silver-colored alkaline Earth metal that is even softer than calcium. Strontium compounds are quite common and have a variety of uses—from fireworks to cement to toothpaste. In fireworks, strontium compounds produce deep red explosions. In toothpaste, like the one pictured in the Figure below , the compound strontium chloride reduces tooth sensitivity.

Statoliths are starch-filled plastids that enable plant roots to detect what force?

current

variation

impact

gravity

How does lysozyme destroy bacteria?

by paralyzing them

by antibiotic use

by eating them

by digesting their cell walls

Another barrier is the saliva in the mouth, which is rich in lysozyme—an enzyme that destroys bacteria by digesting their cell walls. The acidic environment of the stomach, which is fatal to many pathogens, is also a barrier. Additionally, the mucus layer of the gastrointestinal tract, respiratory tract, reproductive tract, eyes, ears, and nose traps both microbes and debris, and facilitates their removal. In the case of the upper respiratory tract, ciliated epithelial cells move potentially contaminated mucus upwards to the mouth, where it is then swallowed into the digestive tract, ending up in the harsh acidic environment of the stomach. Considering how often you breathe compared to how often you eat or perform other activities that expose you to pathogens, it is not surprising that multiple barrier mechanisms have evolved to work in concert to protect this vital area.

The primary role of leaves is to collect what?

precipitation

pollen

insects

sunlight

Plants have specialized organs that help them survive and reproduce in a great diversity of habitats. Major organs of most plants include roots, stems, and leaves. Leaves are the keys not only to plant life but to all terrestrial life. The primary role of leaves is to collect sunlight and make food by photosynthesis . Despite the fundamental importance of the work they do, there is great diversity in the leaves of plants. However, given the diversity of habitats in which plants live, it’s not surprising that there is no single best way to collect solar energy for photosynthesis.

Temperature can be defined as the average of what type of energy of the molecules?

potential

magnetic

optical

kinetic

Temperature is the average kinetic energy of the molecules.

What lens shape corrects myopia?

curve

flat

convex

concave

Myopia is corrected with a concave lens, while hyperopia is corrected with a convex lens.

What serves to replace nonreproducing specialized cells as needed in the adult body?

dendritic cells

osteoclast cells

monocyte cells

stem cells

In physics, resistance is opposition to the flow of what?

surface flow

temperature charges

capacitance

electrical charges

In physics, resistance is opposition to the flow of electric charges in an electric current as it travels through matter. The SI unit for resistance is the ohm. Resistance occurs because moving electrons in current bump into atoms of matter. Resistance reduces the amount of electrical energy that is transferred through matter. That’s because some of the electrical energy is absorbed by the atoms and changed to other forms of energy, such as heat. You can see an animation of resistance at the level of atoms and electrons at this URL: http://www. physics. org/explorelink. asp?id=1738&q=electricalresistance&currentpage=1&age=0&knowledge=0&item=3.

What organs are the main organs of the urinary system?

gall bladder

spleen

prostate

kidneys

The kidneys are the main organs of the urinary system.

What phase follows ovulation?

varicose phase

interstitial phase

telophase

luteal phase

What is used to measure blood pressure?

barometer

anemometer

spectrometer

sphygmomanometer

Chemistry in Everyday Life Measuring Blood Pressure Blood pressure is measured using a device called a sphygmomanometer (Greek sphygmos = “pulse”). It consists of an inflatable cuff to restrict blood flow, a manometer to measure the pressure, and a method of determining when blood flow begins and when it becomes impeded (Figure 9.6). Since its invention in 1881, it has been an essential medical device. There are many types of sphygmomanometers: manual ones that require a stethoscope and are used by medical professionals; mercury ones, used when the most accuracy is required; less accurate mechanical ones; and digital ones that can be used with little training but that have limitations. When using a sphygmomanometer, the cuff is placed around the upper arm and inflated until blood flow is completely blocked, then slowly released. As the heart beats, blood forced through the arteries causes a rise in pressure. This rise in pressure at which blood flow begins is the systolic pressure—the peak pressure in the cardiac cycle. When the cuff’s pressure equals the arterial systolic pressure, blood flows past the cuff, creating audible sounds that can be heard using a stethoscope. This is followed by a decrease in pressure as the heart’s ventricles prepare for another beat. As cuff pressure continues to decrease, eventually sound is no longer heard; this is the diastolic pressure—the lowest pressure (resting phase) in the cardiac cycle. Blood pressure units from a sphygmomanometer are in terms of millimeters of mercury (mm Hg).

Are the lungs organs of the excretory system, the respiratory system, or both?

neither

excretory

respiratory

both

The lungs release carbon dioxide into the air. Carbon dioxide is a gaseous waste product of the cells. Wastes are excreted from the body by the excretory system. Therefore, the lungs are organs of the excretory system as well as the respiratory system.

Light has the properties of both a wave and what else?

electron

atom

nucleus

particle

Light has properties of both a wave and a particle.

Hagfishes have a skull made of what?

bone

gelatin

chitin

cartilage

Water molds are commonly found in moist soil and where else?

crust water

methane water

standing water

surface water

Water molds are commonly found in moist soil and surface water. Many water molds are plant pathogens or fish parasites.

What is considered to be a person's entire genetic information?

organism

chromosome

biosphere

genome

A person’s genome is all of his or her genetic information. In other words, the human genome is all the information that makes us human. And unless you have an identical twin, your genome is unique. No one else has a genome just like yours, though all our genomes are similar.

Where does cellular respiration occur?

Golgi apparatus

nucleus

chloroplasts

mitochondria

Yes. Photosynthesis occurs in the chloroplasts, whereas cellular respiration occurs in the mitochondria. Photosynthesis makes glucose and oxygen, which are then used as the starting products for cellular respiration. Cellular respiration makes carbon dioxide and water (and ATP), which are the starting products (together with sunlight) for photosynthesis.

What are jellyfish and other cnidarian's stingers called?

phenocrysts

prokaryotes

necrocytes

nematocysts

Cnidarians such as jellyfish have radial symmetry. Flatworms and roundworms, which you will read about next, have bilateral symmetry.

What is tube-shaped and brings urine from the kidneys to the urinary bladder?

fallopian tube

gametophytes

vas deferens

ureters

Ureters are tube-shaped and bring urine from the kidneys to the urinary bladder.

When solvent molecules selectively pass through a membrane from a dilute solution to concentrated solution, what process is occurring?

diffusion

plasmolysis

active transport

osmosis

(a) Two solutions of differing concentrations are placed on either side of a semipermeable membrane. (b) When osmosis occurs, solvent molecules selectively pass through the membrane from the dilute solution to the concentrated solution, diluting it until the two concentrations are the same. The pressure exerted by the different height of the solution on the right is called the osmotic pressure. The osmotic pressure of a solution is easy to calculate:.

Water seeping into the ground is known as?

precipitation

invasion

accumulation

infiltration

Infiltration is the process by which water soaks into the ground. Some of the water may seep deep underground. Some may stay in the soil, where plants can absorb it with their roots.

What body system gets rid of waste?

nervous system

digestive system

Muscular system

excretory system

So what happens to your body's wastes? Obviously, you must get rid of them. This is the job of the excretory system. You remove waste as a gas (carbon dioxide), as a liquid (urine and sweat), and as a solid. Excretion is the process of removing wastes and excess water from the body.

Through what form of energy transfer does the sun's energy travel?

Fusion

solar burst

convection

radiation

Radiation is the transfer of energy by waves. Energy can travel as waves through air or empty space. The Sun's energy travels through space by radiation. After sunlight heats the planet's surface, some heat radiates back into the atmosphere.

What are the only regions of space that electrons can occupy?

inside protons

galaxies

inside nuclei

orbits

Electrons can occupy only certain regions of space, called orbits.

What appears in autumn when cool air moves over a warm lake?

movement fog

misty fog

feature fog

steam fog

Steam fog appears in autumn when cool air moves over a warm lake. Water evaporates from the lake surface. As the water vapor cools, it condenses. The fog appears like steam.

All cells need what for processes like active transport?

oxygen

hydrogen

sunlight

energy

All cells, including both plant and animal cells, need energy for processes such as active transport. How do cells obtain the energy they need?.

In certain populations, some of the chromosomes have become what?

dissolved

elongated

composed

fused

What occurs as a result of the discharge of static electricity?

drought

thunder

clouds

lightning

Zachary Wilson. Lightning is the result of the discharge of static electricity . CC BY-NC 3.0.