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What is the term for a mutually beneficial relationship in which one organism lives inside the other?	parthenogenesis	parasite	symbiosis	endosymbiosis	Endosymbiosis We have mentioned that both mitochondria and chloroplasts contain DNA and ribosomes. Have you wondered why? Strong evidence points to endosymbiosis as the explanation. Symbiosis is a relationship in which organisms from two separate species depend on each other for their survival. Endosymbiosis (endo- = “within”) is a mutually beneficial relationship in which one organism lives inside the other. Endosymbiotic relationships abound in nature. We have already mentioned that microbes that produce vitamin K live inside the human gut. This relationship is beneficial for us because we are unable to synthesize vitamin K. It is also beneficial for the microbes because they are protected from other organisms and from drying out, and they receive abundant food from the environment of the large intestine. Scientists have long noticed that bacteria, mitochondria, and chloroplasts are similar in size. We also know that bacteria have DNA and ribosomes, just as mitochondria and chloroplasts do. Scientists believe that host cells and bacteria formed an endosymbiotic relationship when the host cells ingested both aerobic and autotrophic bacteria (cyanobacteria) but did not destroy them. Through many millions of years of evolution, these ingested bacteria became more specialized in their functions, with the aerobic bacteria becoming mitochondria and the autotrophic bacteria becoming chloroplasts. The Central Vacuole Previously, we mentioned vacuoles as essential components of plant cells. If you look at Figure 4.8b, you will see that plant cells each have a large central vacuole that occupies most of the area of the cell. The central vacuole plays a key role in regulating the cell’s concentration of water in changing environmental conditions. Have you ever noticed that if you forget to water a plant for a few days, it wilts? That’s because as the water concentration in the soil becomes lower than the water concentration in the plant, water moves out of the central vacuoles and cytoplasm. As the central vacuole shrinks, it leaves the cell wall unsupported. This loss of support to the cell walls of plant cells results in the wilted appearance of the plant.
All new alleles are formed by what types of mutations?	ordinary	chaotic	systemic	random
What are seeds plants that produce naked seeds in cones called?	angiosperms	cytoplasm	lipids	gymnosperms	Gymnosperms are seed plants that produce naked seeds in cones. There are about 1000 species of gymnosperms. Conifers are the most common group of gymnosperms. The spruce tree in Figure below is an example of a conifer.
Water is the solvent in solutions called acids and?	nutrients	proteins	alkalines	bases	Water is the solvent in solutions called acids and bases. To understand acids and bases, it is important to know more about pure water, in which nothing is dissolved. In pure water (such as distilled water), a tiny fraction of water molecules naturally breaks down, or dissociates, to form ions. An ion is an electrically charged atom or molecule. The dissociation of pure water into ions is represented by the chemical equation:.
What two gases are the main components of air?	hydrogen and helium	oxygen and helium	carbon and oxygen	nitrogen and oxygen	A: Other examples of liquid mixtures include salt water and salad dressing. Air is a mixture of gases, mainly nitrogen and oxygen. The rock pictured in the Figure below is a solid mixture.
Anaerobic prokaryotes can live without what compound in their environment (it's a compound that people do need to live)?	nitrogen	carbon	Hydrogen	oxygen	Aerobic prokaryotes live in habitats with oxygen. Anaerobic prokaryotes live in habitats without oxygen. Prokaryotes may also be adapted to habitats that are hot, moderate, or cold in temperature.
What part of earth do many animals use for navigation?	molten core	oceans	atmosphere	magnetic field	Another benefit of Earth’s magnetic field is its use for navigation. People use compasses to detect Earth’s magnetic north pole and tell direction. Many animals have natural “compasses” that work just as well. For example, the loggerhead turtle in the Figure below senses the direction and strength of Earth’s magnetic field and uses it to navigate along migration routes. Many migratory bird species can also sense the magnetic field and use it for navigation. Recent research suggests that they may have structures in their eyes that let them see Earth’s magnetic field as a visual pattern. You can learn more at this URL: http://www. smithsonianmag. com/science-nature/How-Do-Birds-Find-Their-Way-Home. html.
Endocytosis and exocytosis are types of vesicle transport that carry very large molecules across what structure?	dermis	cell substrate	the heart	cell membrane	Illustration of the two types of vesicle transport, exocytosis and endocytosis. Endocytosis and exocytosis are types of vesicle transport that carry very large molecules across the cell membrane.
What are biochemical compounds that living things use to store energy and make cell membranes?	nucleic acid	carbohydrates	proteins	lipids	Lipids are biochemical compounds that living things use to store energy and make cell membranes. Types of lipids include fats, oils, and phospholipids.
What happens to the volume of a balloon when you add moles of gas to it by blowing up?	stays the same	changes randomly	decreases	increases	where is the number of moles of gas and is a constant. Avogadro’s law is in evidence whenever you blow up a balloon. The volume of the balloon increases as you add moles of gas to the balloon by blowing it up.
The addition of starting materials and the removal of end products prevent metabolism from reaching what state?	imbalance	constant	inequality	equilibrium
In what year was the hardy-weinberg theorem formulated?	1928	1938	1901	1908	Evolution occurs in a population when allele frequencies change over time. What causes allele frequencies to change? That question was answered by Godfrey Hardy and Wilhelm Weinberg in 1908 (see the Hardy-Weinberg Theorem concept).
The regulation of gene expression is extremely important during the development of what?	tissues	cells	protein	organism	3. Name and describe the division of gymnosperms.
What does a virus inject into the host cell?	proteins acid	cells acid	Acetic acid	nucleic acid	22.2.1 Lytic Cycle 1. Attachment: The virus binds to specific receptors on the host cell. Entry: There are two ways in which a virus can enter cells. Firstly, the virus can inject its nucleic acid into the host cell. Secondly, if a virus is contained in an envelope, the host cell can phagocytosise the entire virus particle into a vacuole. When the virus breaks out of the vacuole, it then releases its nucleic acid into the cell. Replication: The virus's nucleic acid instructs the host cell to replicate the virus's DNA or RNA. Assembly: New virus particles are assembled. Lysis and Release: The virus directs the production of an enzyme which damages the host cell wall, causing the host cell to swell and burst. The newly formed virus particles are now released.
Mutations in regulatory genes that normally control the cell cycle cause what?	illness	tumors	anxiety	cancer	Mutations in regulatory genes that normally control the cell cycle cause cancer.
Blood is made up of red blood cells, white blood cells, platelets, and what else?	potassium	pathogens	hemoglobin	plasma	Did you know that blood is a tissue? Blood is a fluid connective tissue that is made up of red blood cells, white blood cells, platelets, and plasma. The cells that make up blood are pictured below ( Figure below ). The different parts of blood have different roles.
What is the term for the study of how living things interact with each other and with their environment?	anthropology	biology	radiology	ecology	Ecology is the study of how living things interact with each other and with their environment. It is a major branch of biology, but has areas of overlap with geography, geology, climatology, and other sciences. This lesson introduces fundamental concepts in ecology, beginning with organisms and the environment.
What takes place directly after developing a hypothesis in the scientific method process?	independent variables	gathering materials	making a conclusion	testing the hypothesis	Scientific method is a process consisting of making observations, developing a hypothesis, and testing that hypothesis.
What should you use to protect your eyes from chemicals?	your hands	contacts	certain goggles	eye goggles
Because action potentials are so brief, a neuron can produce hundreds per what?	lifetime	day	minute	second
Darwin coined what term to refer to an organism’s relative ability to survive and produce fertile offspring?	strength	momentum	metabolism	fitness	Darwin coined the term fitness to refer to an organism’s relative ability to survive and produce fertile offspring. Nature selects the variations that are most useful. Therefore, he called this type of selection natural selection.
At high pressures, how are the molecules of a gas crowded?	small together	few together	further apart	closer together	Particles of a hypothetical ideal gas have no significant volume and do not attract or repel each other. In general, real gases approximate this behavior at relatively low pressures and high temperatures. However, at high pressures, the molecules of a gas are crowded closer together, and the amount of empty space between the molecules is reduced. At these higher pressures, the volume of the gas molecules themselves becomes appreciable relative to the total volume occupied by the gas (Figure 9.36). The gas therefore becomes less compressible at these high pressures, and although its volume continues to decrease with increasing pressure, this decrease is not proportional as predicted by Boyle’s law.
The number of possible isomers increases tremendously as carbon skeletons increase in what?	weight	variation	mass	size
What are vascular plants that produce seeds in cones called?	angiosperms	evergreen	deciduous	gymnosperms	Gymnosperms are vascular plants that produce seeds in cones. Examples include conifers such as pine and spruce trees. The gymnosperm life cycle has a very dominant sporophyte generation. Both gametophytes and the next generation’s new sporophytes develop on the sporophyte parent plant. Figure below is a diagram of a gymnosperm life cycle.
What does photosynthesis change light energy into?	radiation energy	electrical energy	carbon energy	chemical energy	Photosynthesis changes light energy to chemical energy. The chemical energy is stored in the bonds of glucose molecules. Glucose, in turn, is used for energy by the cells of almost all living things. Photosynthetic organisms such as plants make their own glucose. Other organisms get glucose by consuming plants (or organisms that consume plants).
Addiction affects what type of chemical receptors within the brain?	bind receptors	mitochondria receptors	serotonin receptors	dopamine receptors	Figure above shows the accumulation of radioactive compounds that bind to dopamine receptors. The non-addicted individuals have large numbers of receptors for dopamine. The addicted persons show less binding to these receptors, indicating that fewer receptors are present.
What is the ability of an atom to emit, or give off, charged particles and energy from the nucleus?	electromagnetism	magnetism	electrolysis	radioactivity	Radioactivity is the ability of an atom to emit, or give off, charged particles and energy from the nucleus. The charged particles and energy are called by the general term radiation . Only unstable nuclei emit radiation. When they do, they gain or lose protons. Then the atoms become different elements. (Be careful not to confuse this radiation with electromagnetic radiation, which has to do with the light given off by atoms as they absorb and then emit energy. ).
What group of gases are unusually unreactive?	halogens	volcanic gases	greenhouse gases	noble gases	Nonmetals tend to gain electrons in chemical reactions and have a high attraction to electrons within a compound. The most reactive nonmetals reside in the upper right portion of the periodic table. Since the noble gases are an unusually unreactive group, the element fluorine is the most reactive nonmetal. It is also not found in nature as a free element. Fluorine gas reacts explosively with many other elements and compounds and is considered to be one of the most dangerous known substances.
A point defect can be an atom missing from a site in the crystal known as a what?	vacuum	void	deficiency	vacancy	Summary Real crystals contain large numbers of defects. Defects may affect only a single point in the lattice (a point defect), a row of lattice points (a line defect), or a plane of atoms (a plane defect). A point defect can be an atom missing from a site in the crystal (a vacancy) or an impurity atom that occupies.
What is the place called where the axon of one neuron meets the dendrite of another?	apoptosis	uptake	neurotransmitter	synapse	The place where the axon of one neuron meets the dendrite of another is called a synapse . Synapses are also found between neurons and other types of cells, such as muscle cells. The axon of the sending neuron does not actually touch the dendrite of the receiving neuron. There is a tiny gap between them, the synaptic cleft ( Figure below ).
Organic chemistry is the study of the chemistry of what?	oxidation	hydrogen	metals	carbon compounds	Organic chemistry is the study of the chemistry of carbon compounds.
Gastropods, cephalopods, and bivalves are examples of what class?	cetaceans	animals	invertebrates	mollusks	Mollusks are divided into ten living classes, including the familiar gastropods, cephalopods, and bivalves.
What type of cholesterol is commonly referred to as bad?	insulin	unsaturated	hdl	ldl	When you get your cholesterol tested, they are measuring not only the total amount of cholesterol in the blood, but also whether it is being transported by LDL or HDL. All of these values are important for assessing the likelihood of a heart attack. Total cholesterol gives an idea of the overall cholesterol load in the body. The LDL cholesterol (sometimes referred to as “bad” cholesterol) is more likely to be incorporated into a cell or a plaque, so it is important that these levels below. Conversely, since cholesterol being carried by HDL (“good” cholesterol) is being transported away from the rest of the body and into the liver for disposal, higher HDL levels are generally considered beneficial.
Where does most natural gas come from?	alchemy	recycled cooking oil	oceans	wells that produce petroleum	Most natural gas comes from the wells that produce petroleum. An increasing amount comes from a new method. Hydraulic fracturing, called fracking , is very much in the news lately. Fracking makes it easier and quicker to get natural gas from the rock ( Figure below ).
Medical problems associated with the body responding poorly to insulin are commonly associated with what disease?	colitis	AIDS	pertussis	diabetes	In some cases, an endocrine gland secretes a normal amount of hormone, but target cells do not respond to the hormone. Often, this is because target cells have become resistant to the hormone. Type 2 diabetes is an example of this type of endocrine disorder. In type 2 diabetes, body cells do not respond to normal amounts of insulin. As a result, cells do not take up glucose and the amount of glucose in the blood becomes too high. This type of diabetes is usually treated with medication and diet. The addition of extra insulin to the treatment can help some patients.
The pancreatic hormones insulin and glucagon maintain glucose homeostasis by tightly regulating the synthesis and breakdown of what?	pathway	lipids	enzyme	glycogen
The marsupial embryo is nourished inside the uterus with food from a yolk sac instead of through a what?	umbilical cord	stomach	ovum	placenta	The marsupial embryo is nourished inside the uterus with food from a yolk sac instead of through a placenta. The yolk sac stores enough food for the short period of time the embryo remains in the uterus. After the embryo is born, it moves into the mother’s pouch, where it clings to a nipple. It remains inside the pouch for several months while it continues to grow and develop. Even after the offspring is big enough to leave the pouch, it may often return to the pouch for warmth and nourishment. Eventually, the offspring is mature enough to remain outside the pouch on its own.
The substances that comprise heterogeneous mixtures can also be separated by what means?	atmospheric	thermal	chemical	physical	The substances that comprise heterogeneous mixtures can also be separated by physical means. We will discuss separation techniques in the following lesson.
What type of organism has spores that are spread by water and wind?	yeast	Plants	Trees	fungi	Spores may be dispersed by moving water, wind, or other organisms. Some fungi even have “cannons” that “shoot” the spores far from the parent organism. This helps to ensure that the offspring will not have to compete with the parents for space or other resources. You are probably familiar with puffballs, like the one in Figure below . They release a cloud of spores when knocked or stepped on. Wherever the spores happen to land, they do not germinate until conditions are favorable for growth. Then they develop into new hyphae.
Through which organ do hookworm larvae enter the human body?	through the mouth	through the lungs	through the rectum	through the skin	Parasitic roundworms may have plant, vertebrate, or invertebrate hosts. Several species have human hosts. For example, hookworms, like the one in Figure below , are human parasites. They infect the human intestine. They are named for the hooks they use to grab onto the host’s tissues. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Adults lay eggs, which pass out of the host in feces. Then the cycle repeats.
Inside a cylinder, thermal energy is converted to what type of energy of the moving piston?	electrochemical energy	residual energy	horsepower	kinetic energy	Thermal energy is converted to the kinetic energy of the moving piston inside the cylinder. The moving piston, in turn, can be used to turn a turbine or do other useful work.
To the extent that behaviors are controlled by what, they may evolve through natural selection?	mutation	rna	dna	genes	To the extent that behaviors are controlled by genes, they may evolve through natural selection. If behaviors increase fitness , they are likely to become more common over time. If they decrease fitness, they are likely to become less common.
What kind of muscle relationship generally produces back-and-forth movement of a body part?	synchronized muscles	complementary muscles	cooperative muscles	antagonistic muscles
Science is a process of knowing about the natural universe through what two actions?	guessing and observing	thinking and guessing	changes and experimentation	observation and experimentation	Science is a process of knowing about the natural universe through observation and experiment.
Through a process called electromagnetic induction, generators change what energy form of a spinning turbine to electrical energy?	electric	potential	seismic	kinetic	Generators change the kinetic energy of a spinning turbine to electrical energy in a process called electromagnetic induction. You can read about generators and how they work in the chapter "Electromagnetism. ".
Footprints, burrows, and waste are considered what type of fossils?	morphology fossils	movement fossils	crater fossils	trace fossils	Preserved traces can include footprints, burrows, or even wastes. Examples of these types of fossils, called trace fossils are picture below ( Figure below and Figure below ).
What process of allows multicellular organisms to grow and repair themselves?	DNA division	proteins division	atom split	cell division	The process of cell division is how multicellular organisms grow and repair themselves. It is also how many organisms produce offspring. For many single-celled organisms, asexual reproduction is a similar process. The parent cell simply divides to form two daughter cells that are identical to the parent. Asexual reproduction produces offspring that are genetically identical to the parent, whereas sexual reproduction produces a similar, but genetically unique offspring. In sexual reproduction, meiosis produces haploid gametes that fuse during fertilization to produce a diploid zygote ( Figure below ). In other words, a child inherits half of the genetic material from each parent. Look at the family in Figure below . The children resemble their parents, but they are not identical to them. Instead, each has a unique combination of characteristics inherited from both parents. The children, of course, result from sexual reproduction.
What is the process of a confined gas escaping through a tiny hole in its container called?	dilution	effluent	dissipation	effusion	Another related process is effusion. Effusion is the process of a confined gas escaping through a tiny hole in its container. Effusion can be observed by the fact that a helium-filled balloon will stop floating and sink to the floor after a day or so. This is because the helium gas effuses through tiny pores in the balloon. Both diffusion and effusion are related to the speed at which various gas molecules move. Gases that have a lower molar mass effuse and diffuse at a faster rate than gases that have a higher molar mass. While they are similar processes, there is a key difference between diffusion and effusion. Diffusion describes the process of a gas spreading out at a constant pressure, such as throughout a room. Effusion, on the other hand, describes the process of a gas spreading out from a high pressure surroundings to lower pressure surroundings.
What is a relationship between living things that depend on the same resources?	contention	parasitic	symbiotic	competition	Competition is a relationship between living things that depend on the same resources. The resources may be food, water, or anything else they both need. Competition occurs whenever they both try to get the same resources in the same place and at the same time. The two organisms are likely to come into conflict, and the organism with better adaptations may win out over the other organism.
What is the measure of an individual’s weight-to-height ratio called?	density index (di)	body density index (bdi)	body matter index (bmi)	body mass index (bmi)	Metabolism and Obesity Obesity in the United States is epidemic. The rate of obesity has been steadily rising since the 1980s. In the 1990s, most states reported that less than 10 percent of their populations was obese, and the state with the highest rate reported that only 15 percent of their population was considered obese. By 2010, the U. Centers for Disease Control and Prevention reported that nearly 36 percent of adults over 20 years old were obese and an additional 33 percent were overweight, leaving only about 30 percent of the population at a healthy weight. These studies find the highest levels of obesity are concentrated in the southern states. They also find the level of childhood obesity is rising. Obesity is defined by the body mass index (BMI), which is a measure of an individual’s weight-to-height ratio. The normal, or healthy, BMI range is between 18 and 24.9 kg/m2. Overweight is defined as a BMI of 25 to 29.9 kg/m2, and obesity is considered to be a BMI greater than 30 kg/m2. Obesity can arise from a number of factors, including overeating, poor diet, sedentary lifestyle, limited sleep, genetic factors, and even diseases or drugs. Severe obesity (morbid obesity) or long-term obesity can result in serious medical conditions, including coronary heart disease; type 2 diabetes; endometrial, breast, or colon cancer; hypertension (high blood pressure); dyslipidemia (high cholesterol or elevated triglycerides); stroke; liver disease; gall bladder disease; sleep apnea or respiratory diseases; osteoarthritis; and infertility. Research has shown that losing weight can help reduce or reverse the complications associated with these conditions.
When you are walking on a sidewalk, what occurs between your shoes and the concrete each time you put down your foot?	grip	movement	progress	static friction	Static friction acts on objects when they are resting on a surface. For example, if you are walking on a sidewalk, there is static friction between your shoes and the concrete each time you put down your foot (see Figure below ). Without this static friction, your feet would slip out from under you, making it difficult to walk. Static friction also allows you to sit in a chair without sliding to the floor. Can you think of other examples of static friction?.
According to the english system measurement, how much is equal to 2 pints, 1 quart, and ¼ of a gallon?	1 cup	2 cups	3 cups	4 cups	Many quantities can be expressed in several different ways. The English system measurement of 4 cups is also equal to 2 pints, 1 quart, and ¼ of a gallon.
Many important crops, such as corn, are planted and harvested as what?	berries	trees	cuttings	seeds	Many important crops, such as corn, are planted and harvested as seeds. These seeds are important sources of food. For example, corn is ground into feed for chickens and cows. And corn syrup is used to sweeten beverages and candy. But most importantly, seeds are the starting point for a new plant.
The turbine of a windmill spins and creates what?	lightning	grains	pollution	electricity	Wind power uses moving air as a source of energy. Some types of wind power have been around for a long time. People have used windmills to grind grain and pump water for hundreds of years. Sailing ships have depended on wind for millennia. Wind is now used to generate electricity. Moving air can make a turbine spin, just like moving water can. Moving air has kinetic energy. When wind hits the blades of the turbine, the kinetic energy makes the blades move. The turbine spins and creates electricity.
Found in cord blood and other sources, what kind of cells hold the promise of renewing and repairing body tissues?	neurons	red blood cells	white blood cells	stem cells	Stem Cell Research Stem cell research aims to find ways to use stem cells to regenerate and repair cellular damage. Over time, most adult cells undergo the wear and tear of aging and lose their ability to divide and repair themselves. Stem cells do not display a particular morphology or function. Adult stem cells, which exist as a small subset of cells in most tissues, keep dividing and can differentiate into a number of specialized cells generally formed by that tissue. These cells enable the body to renew and repair body tissues. The mechanisms that induce a non-differentiated cell to become a specialized cell are poorly understood. In a laboratory setting, it is possible to induce stem cells to differentiate into specialized cells by changing the physical and chemical conditions of growth. Several sources of stem cells are used experimentally and are classified according to their origin and potential for differentiation. Human embryonic stem cells (hESCs) are extracted from embryos and are pluripotent. The adult stem cells that are present in many organs and differentiated tissues, such as bone marrow and skin, are multipotent, being limited in differentiation to the types of cells found in those tissues. The stem cells isolated from umbilical cord blood are also multipotent, as are cells from deciduous teeth (baby teeth). Researchers have recently developed induced pluripotent stem cells (iPSCs) from mouse and human adult stem cells. These cells are genetically reprogrammed multipotent adult cells that function like embryonic stem cells; they are capable of generating cells characteristic of all three germ layers. Because of their capacity to divide and differentiate into specialized cells, stem cells offer a potential treatment for diseases such as diabetes and heart disease (Figure 3.36). Cell-based therapy refers to treatment in which stem cells induced to differentiate in a growth dish are injected into a patient to repair damaged or destroyed cells or tissues. Many obstacles must be overcome for the application of cell-based therapy. Although embryonic stem cells have a nearly unlimited range of differentiation potential, they are seen as foreign by the patient’s immune system and may trigger rejection. Also, the destruction of embryos to isolate embryonic stem cells raises considerable ethical and legal questions.
Which law explains why a ship weighing thousands of metric tons floats on water?	water pressure law	hofstadter ' law	ganymede ' law	archimedes' law	Do you see the man sitting on top of this tanker truck? He gives you a sense of how big the truck is. What’s behind the truck? Is it a huge apartment complex? It’s just as massive as a very large building, but it’s not even resting on land. It’s a giant cruise ship, and it’s floating on water. The ship weighs about 100,000 metric tons. How can such a tremendous weight float on water? Why doesn’t it sink to the bottom of the ocean instead? Archimedes’ law explains why.
The urinary system can be considered a smaller part of what other body system?	sensory	circulatory	extraneous	excretory	Sometimes, the urinary system ( Figure below ) is called the excretory system. But the urinary system is only one part of the excretory system. Recall that the excretory system is also made up of the skin, lungs, and large intestine, as well as the kidneys. The urinary system is the organ system that makes, stores, and gets rid of urine.
Essential minerals that the body needs in tiny quantities are called what?	byproduct minerals	flux minerals	draw minerals	trace minerals	Food and Drink App: Vitamins and Minerals Vitamins are nutrients that our bodies need in small amounts but cannot synthesize; therefore, they must be obtained from the diet. The word vitamin comes from “vital amine” because it was once thought that all these compounds had an amine group (NH2) in it. This is not actually true, but the name stuck anyway. All vitamins are covalently bonded molecules. Most of them are commonly named with a letter, although all of them also have formal chemical names. Thus vitamin A is also called retinol, vitamin C is called ascorbic acid, and vitamin E is called tocopherol. There is no single vitamin B; there is a group of substances called the B complex vitamins that are all water soluble and participate in cell metabolism. If a diet is lacking in a vitamin, diseases such as scurvy or rickets develop. Luckily, all vitamins are available as supplements, so any dietary deficiency in a vitamin can be easily corrected. A mineral is any chemical element other than carbon, hydrogen, oxygen, or nitrogen that is needed by the body. Minerals that the body needs in quantity include sodium, potassium, magnesium, calcium, phosphorus, sulfur, and chlorine. Essential minerals that the body needs in tiny quantities (so-called trace elements) include manganese, iron, cobalt, nickel, copper, zinc, molybdenum, selenium, and iodine. Minerals are also obtained from the diet. Interestingly,.
The process by which leaves collect sunlight and make food is called this?	pollination	budding	glycolysis	photosynthesis	The primary function of leaves is to collect sunlight and make food by photosynthesis.
What are the three types of rna involved in protein synthesis?	organic , transfer , and ribosomal	messenger, organic and transfer	messenger, transfer, and organic	messenger, transfer, and ribosomal	There are three types of RNA involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribisomal RNA (rRNA). All three of these nucleic acids work together to produce a protein. The mRNA takes the genetic instructions from the nucleus to the cytoplasm, where the ribosomes are located. Ribosomes are the organelles where the proteins are made. The ribosomes themselves are made out of rRNA and other proteins. The mRNA binds to the ribosome, bringing the genetic instructions to order the amino acids to the site of protein synthesis. Finally, the tRNA brings the correct amino acid to the ribosome ( Figure below and Figure below ). In mRNA, the four nucleotides (A, C, G, and U) are arranged into codons of three bases each. Each codon encodes for a specific amino acid, except for the stop codons , which terminate protein synthesis. tRNA, which has a specific “3-leaf clover structure,” contains a three base region called the anticodon , which can base pair to the corresponding three-base codon region on mRNA. More will be discussed on these processes in the Protein Synthesis: The Genetic Code (Advanced) and Protein Synthesis: Translation (Advanced) concepts.
What is the term for chordates with a vertebral column and endoskeleton of cartilage and bone?	mammel	am	insect	vertebrate	Vertebrates are chordates with a vertebral column and endoskeleton of cartilage and bone. Vertebrates also have several organ systems.
What does a keratometer measure in the cornea?	Width	diameter	Lenght	curve	25.7 Image Formation by Mirrors 53. What is the focal length of a makeup mirror that has a power of 1.50 D? 54. Some telephoto cameras use a mirror rather than a lens. What radius of curvature mirror is needed to replace a 800 mm focal length telephoto lens? 55. (a) Calculate the focal length of the mirror formed by the shiny back of a spoon that has a 3.00 cm radius of curvature. (b) What is its power in diopters? 56. Find the magnification of the heater element in Example 25.9. Note that its large magnitude helps spread out the reflected energy. What is the focal length of a makeup mirror that produces a magnification of 1.50 when a person’s face is 12.0 cm away? Explicitly show how you follow the steps in the Problem-Solving Strategy for Mirrors. A shopper standing 3.00 m from a convex security mirror sees his image with a magnification of 0.250. (a) Where is his image? (b) What is the focal length of the mirror? (c) What is its radius of curvature? Explicitly show how you follow the steps in the Problem-Solving Strategy for Mirrors. An object 1.50 cm high is held 3.00 cm from a person’s cornea, and its reflected image is measured to be 0.167 cm high. (a) What is the magnification? (b) Where is the image? (c) Find the radius of curvature of the convex mirror formed by the cornea. (Note that this technique is used by optometrists to measure the curvature of the cornea for contact lens fitting. The instrument used is called a keratometer, or curve measurer. ) 60. Ray tracing for a flat mirror shows that the image is located a distance behind the mirror equal to the distance of the object from the mirror. This is stated d i = –d o , since this is a negative image distance (it is a virtual image). (a) What is the focal length of a flat mirror? (b) What is its power?.
What is it called when an egg develops into an individual without being fertilized?	metamorphosis	symbiosis	abiogenesis	parthenogenesis	Parthenogenesis Parthenogenesis is a form of asexual reproduction in which an egg develops into an individual without being fertilized. The resulting offspring can be either haploid or diploid, depending on the process in the species. Parthenogenesis occurs in invertebrates such as water fleas, rotifers, aphids, stick insects, and ants, wasps, and bees. Ants, bees, and wasps use parthenogenesis to produce haploid males (drones). The diploid females (workers and queens) are the result of a fertilized egg. Some vertebrate animals—such as certain reptiles, amphibians, and fish—also reproduce through parthenogenesis. Parthenogenesis has been observed in species in which the sexes were separated in terrestrial or marine zoos. Two female Komodo dragons, a hammerhead shark, and a blacktop shark have produced parthenogenic young when the females have been isolated from males. It is possible that the asexual reproduction observed occurred in response to unusual circumstances and would normally not occur.
Many adolescents experience frequent mood swings. name one of the causes for this.	growing hormones	maturing nervous system	psychological changes	surging hormones	Adolescents may have mood swings because of surging hormones.
Through what does the nerve impulses travel to the brain?	oculomotor nerve	abducent nerve	trochlear nerve	optic nerve	When light hits rods and cones, it causes chemical changes. The chemical changes start nerve impulses. The nerve impulses travel to the brain through the optic nerve .
The difference in electric potential energy which allows for an electric charge to move from one position to another is measured by what si unit?	meter	ohm	joule	volt	In general, for an electric charge to move from one position to another, there must be a difference in electric potential energy between the two positions. The difference in electric potential energy is called potential difference, or voltage . Voltage is measured in an SI unit called the volt (V). For example, the terminals of the car battery in Figure below have a potential difference of 12 volts. This difference in voltage results in a spontaneous flow of charges, or electric current.
The properties of the alkali metals are similar to each other as expected for elements in the same what?	farm	class	branch	family	The properties of the alkali metals are similar to each other as expected for elements in the same family. The alkali metals have the largest atomic radii and the lowest first ionization energy in their periods. This combination makes it very easy to remove the single electron in the outermost (valence) shell of each. The easy loss of this valence electron means that these metals readily form stable cations with a charge of 1+. Their reactivity increases with increasing atomic number due to the ease of losing the lone valence electron (decreasing ionization energy). Since oxidation is so easy, the reverse, reduction, is difficult, which explains why it is hard to isolate the elements. The solid alkali metals are very soft; lithium, shown in Figure 18.3, has the lowest density of any metal (0.5 g/cm3). The alkali metals all react vigorously with water to form hydrogen gas and a basic solution of the metal hydroxide. This means they are easier to oxidize than is hydrogen. As an example, the reaction of lithium with water is: 2Li(s) + 2H 2 O(l) ⟶ 2LiOH(aq) + H 2(g).
Which division of the peripheral nervous system carries messages from sense organs and internal organs to the central nervous system?	extrasensory division	vascular division	neural division	sensory division	All other nervous tissue in the body makes up the peripheral nervous system, which has two major divisions. The sensory division carries messages from sense organs and internal organs to the central nervous system. The motor division carries messages from the central nervous system to muscles, internal organs, and glands throughout the body. The motor division is further divided into parts that control involuntary or voluntary responses.
An ether is an organic compound in which two hydrocarbon groups are bonded to the same atom of what?	nitrogen	hydrogen	sulfur	oxygen	An ether is an organic compound in which two hydrocarbon groups are bonded to the same atom of oxygen. An ether is represented by the general formula R−O−R’. The R’ in the formula means that the hydrocarbon group can be the same as R or it can be different. The steps for naming ethers are listed below.
Featuring a stalk-like filament that ends in an anther, what is the male reproductive organ in a flower?	petals	angiosperms	cones	stamen	The male reproductive organ in a flower is the stamen . It has a stalk-like filament that ends in an anther. The anther is where pollen forms.
What controls the movements of hands and arms?	voluntary nervous system	autonomic nervous system	functional nervous system	somatic nervous system	Scott Schram. The somatic nervous system controls the movements of hands and arms . CC BY 2.0.
Refraction happens when light bends from doing what in a new medium?	changing trajectory	changing brightness	changing color	changing speed	Facts are true. Data, gathered correctly, is factual. Facts and data are not subject to opinion or bias.
What is the basic structure that holds plants upright, allowing plants to get the sunlight and air they need?	root	twig	stamen	stem	Stems are organs that hold plants upright. They allow plants to get the sunlight and air they need. Stems also bear leaves, flowers, cones, and smaller stems. These structures grow at points called nodes. The stem between nodes is called an internode. (See Figure below . ).
The waves on the strings of musical instruments are transverse—so are electromagnetic waves, such as visible light. sound waves in air and water are this?	horizontal	symmetrical	hydroelectric	longitudinal	Waves may be transverse, longitudinal, or a combination of the two. (Water waves are actually a combination of transverse and longitudinal. The simplified water wave illustrated in Figure 16.30 shows no longitudinal motion of the bird. ) The waves on the strings of musical instruments are transverse—so are electromagnetic waves, such as visible light. Sound waves in air and water are longitudinal. Their disturbances are periodic variations in pressure that are transmitted in fluids. Fluids do not have appreciable shear strength, and thus the sound waves in them must be longitudinal or compressional. Sound in solids can be both longitudinal and transverse.
What is the name of the elongated bony structure that anchors the anterior thoracic cage?	tibia	pelvis	collar bone	sternum	Sternum The sternum is the elongated bony structure that anchors the anterior thoracic cage. It consists of three parts: the manubrium, body, and xiphoid process. The manubrium is the wider, superior portion of the sternum. The top of the manubrium has a shallow, U-shaped border called the jugular (suprasternal) notch. This can be easily felt at the anterior base of the neck, between the medial ends of the clavicles. The clavicular notch is the shallow depression located on either side at the superior-lateral margins of the manubrium. This is the site of the sternoclavicular joint, between the sternum and clavicle. The first ribs also attach to the manubrium. The elongated, central portion of the sternum is the body. The manubrium and body join together at the sternal angle, so called because the junction between these two components is not flat, but forms a slight bend. The second rib attaches to the sternum at the sternal angle. Since the first rib is hidden behind the clavicle, the second rib is the highest rib that can be identified by palpation. Thus, the sternal angle and second rib are important landmarks for the identification and counting of the lower ribs. Ribs 3–7 attach to the sternal body. The inferior tip of the sternum is the xiphoid process. This small structure is cartilaginous early in life, but gradually becomes ossified starting during middle age.
What is the most numerous species on the planet?	humans	trees	viruses	bacteria	Practically all surfaces. Bacteria can live and grow in practically any environment. It is this ability that has made bacteria the most numerous species on the planet.
What are the earth's two poles called?	west and south	southwest and south	east and west	north and south	A magnet is an object that attracts certain materials such as iron. You’re probably familiar with common bar magnets, like the one shown in the Figure below . Like all magnets, this bar magnet has north and south magnetic poles . The red end of the magnet is the north pole and the blue end is the south pole. The poles are regions where the magnet is strongest. The poles are called north and south because they always line up with Earth’s north-south axis if the magnet is allowed to move freely. (Earth’s axis is the imaginary line around which the planet rotates. ).
Chloroplasts and chromoplasts are examples of which membrane bound organelle containing their own dna?	bacteria	chromosomes	polymers	plastids	Plastids are membrane-bound organelles with their own DNA. Examples are chloroplasts and chromoplasts. Chloroplasts contain the green pigment chlorophyll and carry out photosynthesis. Chromoplasts make and store other pigments. They give flower petals their bright colors.
Birds are the most numerous type of what vertebrates?	ornithopod	arachnipod	amphipod	tetrapod	Birds evolved from a reptile ancestor but they are very different from reptiles today. Birds are also the most numerous tetrapod vertebrates.
Viruses were assumed to exist before they were first seen with an electron microscope in which decade?	1940's	1960's	1890's	1930 ' s	Viruses were assumed to exist before they were first seen with an electron microscope in the 1930s. Multiple hypotheses for viral origins have been proposed.
Matter is always conserved in what type of reaction?	toxic reaction	developed reaction	Quick reaction	chemical reaction	In a chemical reaction, the quantity of each element does not change; there is the same amount of each element in the products as there was in the reactants. This is because matter is always conserved. The conservation of matter is reflected in a reaction’s chemical equation. The same number of atoms of each element appears on each side of the arrow. For example, in the chemical equation above, there are four hydrogen atoms on each side of the arrow. Can you find all four of them on each side of this equation?.
Most flowers carry both stamens and carpels; however, a few species are capable of what and are nicknamed "perfect" flowers?	cloning	sexual reproduction	germination	self-pollination	Most flowers carry both stamens and carpels; however, a few species self-pollinate. These are known as “perfect” flowers because they contain both types of sex organs (Figure 14.25. Biochemical and anatomical barriers to self-pollination promote cross-pollination. Self-pollination is a severe form of inbreeding, and can increase the number of genetic defects in offspring. A plant may have perfect flowers, and thus have both genders in each flower; or, it may have imperfect flowers of both kinds on one plant (Figure 14.28). In each case, such species are called monoecious plants, meaning “one house. ” Some botanists refer to plants with perfect flowers simply as hermaphroditic. Some plants are dioecious, meaning “two houses,” and have male and female flowers (“imperfect flowers”) on different plants. In these species, cross-pollination occurs all the time.
The entry of food into the esophagus marks the beginning of the esophageal phase of deglutition and the initiation of this?	propagation	relaxation	digestion	peristalsis	The Esophageal Phase The entry of food into the esophagus marks the beginning of the esophageal phase of deglutition and the initiation of peristalsis. As in the previous phase, the complex neuromuscular actions are controlled by the medulla oblongata. Peristalsis propels the bolus through the esophagus and toward the stomach. The circular muscle layer of the muscularis contracts, pinching the esophageal wall and forcing the bolus forward. At the same time, the longitudinal muscle layer of the muscularis also contracts, shortening this area and pushing out its walls to receive the bolus. In this way, a series of contractions keeps moving food toward the stomach. When the bolus nears the stomach, distention of the esophagus initiates a short reflex relaxation of the lower esophageal sphincter that allows the bolus to pass into the stomach. During the esophageal phase, esophageal glands secrete mucus that lubricates the bolus and minimizes friction.
Where are the seeds in gymnosperms found?	in roots	in leaves	in folds	in cones	Gymnosperms have seeds, but they do not produce fruit. Instead, the seeds of gymnosperms are usually found in cones.
Oil is found in the porous rock layer and trapped by the what?	mantle	\	crystalline layer	impermeable layer	Oil (red) is found in the porous rock layer (yellow) and trapped by the impermeable layer (brown). The folded structure has allowed the oil to pool so a well can be drilled into the reservoir.
The number of valence electrons determines variation of what property in nonmetals?	turbidity	permeability	density	reactivity	Reactivity is how likely an element is to react chemically with other elements. Some nonmetals are extremely reactive, whereas others are completely nonreactive. What explains this variation in nonmetals? The answer is their number of valence electrons. These are the electrons in the outer energy level of an atom that are involved in interactions with other atoms. Let’s look at two examples of nonmetals, fluorine and neon. Simple atomic models of these two elements are shown in the Figure below .
Hydrogen and helium are specifically involved as reactants in what nuclear reaction that is useful for making energy?	nuclear fission	destructive fusion	radioactive fusion	nuclear fusion	The use of nuclear fusion for energy has several pros. Unlike nuclear fission, which involves dangerous radioactive elements, nuclear fusion involves just hydrogen and helium. These elements are harmless. Hydrogen is also very plentiful. There is a huge amount of hydrogen in ocean water. The hydrogen in just a gallon of water could produce as much energy by nuclear fusion as burning 1,140 liters (300 gallons) of gasoline! The hydrogen in the oceans would generate enough energy to supply all the world’s people for a very long time.
What is the most widely used form of renewable energy in the world?	solar	wind	fossil fuel	hydropower	Moving water has energy ( Figure above ). That energy is used to make electricity. Hydroelectric power , or hydropower, harnesses the energy of water moving down a stream. Hydropower is the most widely used form of renewable energy in the world. This abundant energy source provides almost one fifth of the world’s electricity. The energy of waves and tides can also be used to produce water power. At this time, wave and tidal power are rare.
What energy is the energy of motion?	thermal	optimal	potential	kinetic	Kinetic energy is the energy of motion. Any object that is moving possesses kinetic energy. Baseball involves a great deal of kinetic energy. The pitcher throws a ball, imparting kinetic energy to the ball. When the batter swings, the motion of swinging creates kinetic energy in the bat. The collision of the bat with the ball changes the direction and speed of the ball, with the idea of kinetic energy being involved again.
Where do stratus clouds occur in the troposphere?	mid-region	mid to high region	high	low	Stratus clouds occur low in the troposphere. They form in layers that spread horizontally and may cover the entire sky like a thick blanket. Stratus clouds that produce precipitation are called nimbostratus. The prefix nimbo- means “rain. ”.
What kind of movement do planets in the solar system make around the sun?	spinning orbits	optical orbits	round orbits	elliptical orbits	Flickr:Image Editor. Planets in the solar system make elliptical orbits around the Sun . CC BY 2.0.
Which process breaks down glucose to extract energy for cell metabolism?	mitosis	photosynthesis	meiosis	glycolysis	Glycolysis You have read that nearly all of the energy used by living things comes to them in the bonds of the sugar, glucose. Glycolysis is the first step in the breakdown of glucose to extract energy for cell metabolism. Many living organisms carry out glycolysis as part of their metabolism. Glycolysis takes place in the cytoplasm of most prokaryotic and all eukaryotic cells. Glycolysis begins with the six-carbon, ring-shaped structure of a single glucose molecule and ends with two molecules of a three-carbon sugar called pyruvate. Glycolysis consists of two distinct phases. In the first part of the glycolysis pathway, energy is used to make adjustments so that the six-carbon sugar molecule can be split evenly into two three-carbon pyruvate molecules. In the second part of glycolysis, ATP and nicotinamide-adenine dinucleotide (NADH) are produced (Figure 4.13). If the cell cannot catabolize the pyruvate molecules further, it will harvest only two ATP molecules from one molecule of glucose. For example, mature mammalian red blood cells are only capable of glycolysis, which is their sole source of ATP. If glycolysis is interrupted, these cells would eventually die.
What does fluorine attract better than any other element?	magnets	ionic bonds	electron shells	shared electrons	Valence electrons of both atoms are always involved when those two atoms come together to form a chemical bond. Chemical bonds are the basis for how elements combine with one another to form compounds. When these chemical bonds form, atoms of some elements have a greater ability to attract the valence electrons involved in the bond than other elements. Electronegativity is a measure of the ability of an atom to attract shared electrons when the atom is part of a compound. Electronegativity differs from electron affinity because electron affinity is a measure of the actual energy released when an atom gains an electron. In contrast, electronegativity is a relative scale, so it is not measured in units of energy. All elements are compared to one another, and the most electronegative element, fluorine, is assigned an electronegativity value of 3.98. Fluorine attracts shared electrons better than any other element. Figure below shows the electronegativity values of most elements.
What term is used to describe the muscular canal (approximately 10 cm long) that serves as the entrance to the reproductive tract?	urethra	uterus	cervix	vagina	Vagina The vagina, shown at the bottom of Figure 27.9 and Figure 27.9, is a muscular canal (approximately 10 cm long) that serves as the entrance to the reproductive tract. It also serves as the exit from the uterus during menses and childbirth. The outer walls of the anterior and posterior vagina are formed into longitudinal columns, or ridges, and the superior portion of the vagina—called the fornix—meets the protruding uterine cervix. The walls of the vagina are lined with an outer, fibrous adventitia; a middle layer of smooth muscle; and an inner mucous membrane with transverse folds called rugae. Together, the middle and inner layers allow the expansion of the vagina to accommodate intercourse and childbirth. The thin, perforated hymen can partially surround the opening to the vaginal orifice. The hymen can be ruptured with strenuous physical exercise, penile–vaginal intercourse, and childbirth. The Bartholin’s glands and the lesser vestibular glands (located near the clitoris) secrete mucus, which keeps the vestibular area moist. The vagina is home to a normal population of microorganisms that help to protect against infection by pathogenic bacteria, yeast, or other organisms that can enter the vagina. In a healthy woman, the most predominant type of vaginal bacteria is from the genus Lactobacillus. This family of beneficial bacterial flora secretes lactic acid, and thus protects the vagina by maintaining an acidic pH (below 4.5). Potential pathogens are less likely to survive in these acidic conditions. Lactic acid, in combination with other vaginal secretions, makes the vagina a self-cleansing organ. However, douching—or washing out the vagina with fluid—can disrupt the normal balance of healthy microorganisms, and actually increase a woman’s risk for infections and irritation. Indeed, the American College of Obstetricians and Gynecologists recommend that women do not douche, and that they allow the vagina to maintain its normal healthy population of protective microbial flora.
What type of energy travels through space as electrical and magnetic waves?	solar energy	sound energy	mechanical energy	electromagnetic energy	4. Electromagnetic energy is energy that travels through space as electrical and magnetic waves. The light flooding the stage in the Figure above is one type of electromagnetic energy. Other types include radio waves, microwaves, X rays, and gamma rays.
What are subatomic particles of the nucleus called?	isotopes	baryons	cores	nucleons	Summary Subatomic particles of the nucleus (protons and neutrons) are called nucleons. Anuclide is an atom with a particular number of protons and neutrons. An unstable nucleus that decays spontaneously is radioactive, and its emissions are collectively called radioactivity. Isotopes that emit radiation are calledradioisotopes. Each nucleon is attracted to other nucleons by the strong nuclear force. Stable nuclei generally have even numbers of both protons and neutrons and a neutron-to-proton ratio of at least 1. Nuclei that contain magic numbers of protons and neutrons are often especially stable. Superheavy elements, with atomic numbers near 126, may even be stable enough to exist in nature.
What blood pressure reading measures the pressure in the vessels between heartbeats?	systolic	metabolic	plasma	diastolic	40.4 \| Blood Flow and Blood Pressure Regulation By the end of this section, you will be able to: • Describe the system of blood flow through the body • Describe how blood pressure is regulated Blood pressure (BP) is the pressure exerted by blood on the walls of a blood vessel that helps to push blood through the body. Systolic blood pressure measures the amount of pressure that blood exerts on vessels while the heart is beating. The optimal systolic blood pressure is 120 mmHg. Diastolic blood pressure measures the pressure in the vessels between heartbeats. The optimal diastolic blood pressure is 80 mmHg. Many factors can affect blood pressure, such as hormones, stress, exercise, eating, sitting, and standing. Blood flow through the body is regulated by the size of blood vessels, by the action of smooth muscle, by one-way valves, and by the fluid pressure of the blood itself.
What holds ionic and covalent compounds together?	magnetic force	gravity	water	electrostatic attractions	Ionic and covalent compounds are held together by electrostatic attractions between oppositely charged particles. Describe the differences in the nature of the attractions in ionic and covalent compounds. Which class of compounds contains pairs of electrons shared between bonded atoms?.
Amines are bases; they react with acids to form what?	proteins	oils	ions	salts	Amines are bases; they react with acids to form salts.
If water from a spring can't flow downwards, it can spread out to form one of 2 things. what are they?	ocean or river	lake or ocean	ocean or sea	pond or lake	Water flowing out of the ground at a spring may flow downhill and enter a stream. That’s what happens to the water that flows out of Big Spring in Missouri. If the water from a spring can’t flow downhill, it may spread out to form a pond or lake instead. Lake George in New York State, which is pictured in Figure below , is a spring-fed lake. The lake basin was carved by a glacier.

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