BIOL 1408 Exam 1 MC, Practice Quizzes and Class Quizzes

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The three different known biochemical pathways organisms will use to photosynthesize include which of the following?

C3, C4, CAM

What can you conclude from this figure?

Cells with high rates of metabolic activity appear to have more mitochondria.

Using the graphic above as a guide, what is Step 4 in the scientific process?

Conduct a critical experiment.

What is Step 4 in the scientific process?

Conduct a critical experiment.

Which of the following questions CANNOT be answered by the scientific method?

Did the United States act appropriately when it invaded Iraq?

What makes the rough endoplasmic reticulum rough?

It is covered with ribosomes.

A _____________ is a pill that looks identical to a pill that contains the active ingredient in a scientific trial, but contains no active ingredient itself. a) placebo b) treatment c) barbiturate d) capsule e) tablet

A complex polymer built of monosaccharides is called a(n): A) polysaccharide. B) ketone. C) protein. D) polypeptide. E) aldehyde.

A green plant can perform photosynthesis if given nothing more than: a) water, light, and air. b) water. c) light. d) air. e) water and light.

A nucleotide consists of a phosphate group, a pentose sugar, and __________________, all linked together by covalent bonds. A) a nitrogen-containing base B) a phosphorus-containing base C) a polypeptide D) a potassium-containing base E) a triglyceride

The primary function of molecular membranes is the transport of ions and molecules in and out of cells. The movement of molecules from areas of low concentration to those of high concentration against chemical gradients is best described as:

active transport

The diagram above shows the action of beta-blockers in reducing anxiety. In this diagram, the green triangles represent ________________, the yellow figures represent ______________, and the purple ovals represent ______________

adrenaline ; beta-blocker chemicals ; beta-receptors

Enzymes are composed of:

amino acids

The cell on the left is _________________ and the cell on the right is _________________. The organelle labeled B is ________________.

an animal cell ; a plant cell ; a mitochondrion

An atom can be changed into an ion by adding or removing:

an electron.

Photosystems:

are arrangements of light-catching pigments within chloroplasts.

The number of protons in an element, also called its , identifies the element.

atomic number

All matter on earth, both living and nonliving, is made up of:

atoms

"Engaging in aerobic activity three times each week will reduce cholesterol levels" is a: a) control group. b) testable hypothesis. c) scientific control. d) critical experiment. e) All of the above are correct.

Glycoproteins are membrane proteins with bound: a) signaling peptide sequences. b) cofactors. c) carbohydrates. d) phospholipids. e) nucleic acids.

How can science best help each of us understand the role of humans in nature? a) Science can provide us with a set of moral precepts. b) Science can provide us with a specific political agenda. c) Science can provide understanding of how the systems of nature work. d) Science can teach us to love nature. e) None of the above is correct.

How many rotations of the Calvin cycle are required for the production of one glucose molecule? a) 2 b) 3 c) 6 d) 8 e) 12

In a scientific experiment, a control group: a) is less important than an experimental group. b) makes the experiment better, but is not essential. c) can be compared with an experimental group to assess whether one particular variable is causing a change in the experimental group. d) must be kept in a laboratory. e) All of the above are correct.

In animals, exertion without sufficient oxygen leads to the production of: a) pyruvate. b) NADH. c) lactic acid. d) ethanol. e) water.

In glycolysis, one molecule of glucose containing six carbons is converted to two molecules of ________ containing six carbons each. This reaction also yields two molecules of _______ and two molecules of _______. a) sucrose; lactic acid; FADH b) galactose; H2O; ATP c) pyruvate; ATP; NADH d) acetyl-CoA; ADP; Pi e) lactic acid; O2; acetaldehyde

In science, theories tend to be ___________ than hypotheses. a) more speculative b) less scientific c) broader in scope d) more experimental e) more empirical

One important difference between covalent and ionic bonds is that: a) ionic bonds are much stronger than covalent bonds. b) in ionic bonds two atoms share electrons, whereas in covalent bonds one atom gives one or more electrons to the other atom. c) in covalent bonds two atoms share electrons, whereas in ionic bonds one atom gives one or more electrons to the other atom. d) in ionic bonds both protons and electrons can be shared, whereas in covalent bonds only electrons can be shared. e) ionic bonds only occur among water-soluble elements.

Phenylketonuria is an inherited disorder. Affected individuals have a defective enzyme called phenylalanine hydroxylase. The substance these individuals cannot break down is a(n): a) carbohydrate. b) nucleic acid. c) amino acid. d) protein. e) lipid.

Phospholipids assemble spontaneously into bilayers driven by the attraction of their "tail" portions to each other and of their "head" portions to each other. The tail regions are: a) hydrophilic. b) molecularly charged. c) hydrophobic. d) adhesive. e) cohesive.

Potential energy: a) is stored energy unavailable to do work. b) transfers motion to matter. c) is contained in matter placed in certain positions or arrangements. d) contains less energy than kinetic energy. e) is kinetic energy that has not yet been turned to heat.

Prokaryotic organisms lack: a) cell membranes. b) replicator molecules (DNA or RNA). c) organelles. d) metabolism. e) All of the above are correct.

Scientific data: A) cannot be collected in a completely unbiased way. B) are always true. C) are used to support or refute a hypothesis. D) must be collected in laboratories. E) All of the above are true.

Suppose you measure the height of two people. One is a woman who is 5 feet 10 inches tall. The other is a man who is 5 feet 6 inches tall. Which of the following is an appropriate conclusion to draw from these measurements? a) Women are taller than men. b) Some men are taller than some women. c) Some women are taller than some men. d) Men are taller than women. e) The tallest woman is 5 feet 10 inches tall.

What are the two distinct "faces" of the phospholipids that make up the surface membrane of a cell? A) a hydrophilic head and a hydrophobic tail B) a hydrophobic head and a hydrophilic tail C) a phosphate group head and two fatty acid tails D) Both a) and c) are correct. E) Both b) and c) are correct.

The leaves of plants can be thought of as "eating" sunlight. From an energetic perspective this makes sense because:

light energy, like the chemical energy released when the bonds of food molecules are broken, is a type of kinetic energy.

Fermentation reactions generally occur under conditions of:

low oxygen concentrations.

Which of the following organelles is responsible for degrading waste within the cell?

lysosome

The structures labeled D are:

mitochondria

According to the clip, where are the light-harvesting organelles found within plants?

near the surface of the leaves

Which of the following BEST defines diffusion?

net movement of particles from areas of high concentration to areas of low concentration

Phosphate groups are important components of:

nucleic acids

Which of the following is usually employed first by an investigator using the scientific method? A) formulate a hypothesis B) conduct a critical experiment C) make observations D) devise a testable prediction E) analyze data

Which of the following statements about chemical bonds is NOT true? a) Covalent bonds are formed through electron sharing and are quite strong. b) Ionic bonds result from the attraction between two oppositely charged atoms. c) Methane (CH4) is the result of an ionic bond between two oppositely charged atoms of carbon and hydrogen. d) O2 is the result of a covalent bond where two oxygen atoms share two electrons. e) Hydrogen bonds are formed from the attraction between a hydrogen atom and another atom with a slight negative charge.

Which of the following statements about enzymes is NOT true? A) Enzymes help initiate chemical reactions. B) Enzymes are proteins. C) Enzymes are permanently changed when they take place in a chemical reaction. D) Enzymes often induce shape changes in the molecules to which they bind. E) Enzymes speed up chemical reactions.

Which of the following statements is CORRECT? a) The scientific method can be used only to understand scientific phenomena. b) Common sense is usually a good substitute for the scientific method when trying to understand the world. c) A hypothesis that does not generate a testable prediction is not useful. d) It is not necessary to make observations as part of the scientific method. e) All of the above are correct.

Why do coastal areas have milder, less variable climates than inland areas? a) Large bodies of water have high salt concentrations and salt absorbs a large proportion of the light energy that would have warmed the land. b) Coastal areas are concentrated near the equator, which varies less than other parts of the globe in the angle at which the sun's light hits it. c) Large bodies of water, especially oceans, can absorb huge amounts of heat from the sun during warm times of the year, reducing temperature increases on the land. Similarly, during cold times of year the ocean slowly cools, giving off heat that reduces the temperature drop on shore. d) Because water is a good solvent, it is able to dissolve the photons in light, reducing their ability to heat or cool the land. e) None of the above is correct. No one knows why coastal areas have milder, less variable climates than inland areas.

Why is it that creationism can never be accepted as a scientific explanation of the origin of life? a) Because the age of the earth, as given in Genesis, can never be determined. b) Because most scientists are not deeply religious people. c) Because the ideas of creationism cannot be tested through experiment and observation. d) Because creationism, similar to evolution, is a theory and therefore cannot be proved. e) None of the above; creationism can be accepted as a scientific explanation of the origin of life.

Anecdotal evidence:

can appear to reveal links between two phenomena that do not actually exist.

Which of the following foods can be used to produce ATP in cellular respiration?

carbohydrates, proteins and fats.

Energy used in cellular respiration can originate from:

carbohydrates, proteins, and fats.

Everything is made of atoms.

carbon, oxygen, hydrogen, and nitrogen.

All alcoholic beverages are produced as the result of:

cellular respiration by yeast occurring in the absence of oxygen.

Which one of the following organelles is NOT found in both plant and animal cells?

central vacuole

In scientific thinking, which of the following are not subject to revision?

observations

Scientific study always begins with:

observations.

Prokaryotic organisms lack:

organelles

The reddish projections in the figure above, shown on the outside of a cell membrane, are called:

cilia

Once a scientist has formulated a hypothesis that generates a testable prediction, she will:

conduct a critical experiment.

There are three principal types of bonds that hold multiple atoms together. These are:

covalent bonds, ionic bonds, and hydrogen bonds.

A peptide bond is a ________ bond between two __________.

covalent, amino acids

The transport of water across a membrane from a solution of lower solute concentration to a solution of higher solute concentration is best described as:

osmosis

Which by-product of photosynthesis was important in altering the atmosphere of the earth so that aerobic organisms could evolve?

oxygen

In which organelle are lipids synthesized and modified within the eukaryotic cell? A) the Golgi apparatus B) the vesicle C) the rough endoplasmic reticulum D) the smooth endoplasmic reticulum E) the lysosome

What are the resulting products of the splitting of water in photosynthesis? a) electrons and oxygen b) electrons, carbon dioxide, and hydrogen ions c) electrons and carbon dioxide d) electrons, oxygen, and hydrogen ions e) electrons, oxygen, and photons

Just four elements make up more than 96% of the human body. These include all of the following EXCEPT:

phosphorus

Which of the following is NOT a function of the plant vacuole?

photosynthesis

The organelle in the figure is found in:

plants and animals.

Photosynthesis is the process by which __________________ use the energy from sunlight to produce sugar.

plants, some bacteria, and some protistans

plasmodesmata

A complex polymer built of monosaccharides is called a

polysaccharide

Glycogen belongs in the class of molecules known as:

polysaccharides.

If the results of an experiment turn out differently from what you expected, then:

you should explore the reasons for this in the "conclusions" section of your experimental write-up.

Which suffix typically conveys that a substance is a carbohydrate?

-ose

If you toss a coin and it comes up tails on eight consecutive tosses, what is the likelihood it will come up heads on the ninth toss?

1/2

A neutral atom of the most common form of aluminum (Al) has how many electrons?

A neutral atom of the most common form of aluminum (Al) has how many protons? (Use numerals to fill in the blank).

How many phosphates do ADP & ATP each have?

2, 3

Of all the elements that occur on earth, how many are found in your body?

Which of the following statements is CORRECT?

A hypothesis that does not generate a testable prediction is not useful.

If your hypothesis is "Eyewitness testimony is always accurate," which of the following is a reasonable testable prediction?

All of the above are reasonable testable predictions for this hypothesis.

Why is it that creationism can never be accepted as a scientific explanation of the origin of life?

Because the ideas of creationism cannot be tested through experiment and observation.

Which statement about phospholipids is FALSE?

Because their phosphate groups repel each other, they are used as organisms' chief form of short-term energy.

Which of the following statements about cell theory is CORRECT?

Both a) and b) are correct. All organisms are made of cells.

Which of the following is an important difference between the rough endoplasmic reticulum and the smooth endoplasmic reticulum?

Both a) and c) are correct. 3.17: The endoplasmic reticulum is the site where cells build proteins and disarm toxins.

Which of the following has scientific investigation shown to be LEAST reliable in criminal prosecutions?

eyewitness identification

If your hypothesis is "Echinacea reduces the duration and severity of the symptoms of the common cold," what is your null hypothesis?

Echinacea has no effect on the duration and severity of the symptoms of the common cold.

If you were to design an experiment to test whether a particular pathogen caused a disease, which of the following choices would be the first step and which the last step you would make if you followed the scientific method precisely?

First: make observations; Last: draw conclusions

Using the graphic above as a guide, what is Step 2 in the scientific process?

Formulate a hypothesis.

Water molecules form which type of bond with other water molecules?

Hydrogen bonds

Which of the following statements is NOT a scientific theory?

If you talk about biology to your friends, you will probably do better on a biology test.

Before experimental drugs can be brought to market, they must undergo many rigorous trials to ensure they deliver their medical benefits effectively and safely. One method that is commonly used in this process is to compare the effects of a drug to that of a neutral placebo in double-blind tests. Which of the following choices correctly describes a double-blind test?

Neither the researchers nor the study's participants know who is receiving the drug and who is receiving the placebo.

The diagram shows two atoms: Nitrogen (N), and Neon (Ne). Which of the following accurately explains which atom is more likely to bond with another atom?

Nitrogen, as it has three electron vacancies in the outermost shell.

When ATP is hydrolyzed to ADP, what happens?

One phosphate is removed.

Which of the following BEST summarizes the differences between osmosis and diffusion?

Osmosis deals only with water.

Identify which of the following solutions are acids. Mark all correct responses.

Solution of pH 1 Solution of pH 5 Solution of pH 3

Which of the following is the BEST description of a control group in an experiment?

The control group is identical to each test group except for one variable

Which statement is NOT part of the modern cell theory?

The first cell was a eucaryotic cell.

Which of the following statements could NOT arise from making scientific observations?

The quartz crystal I had in my pocket today increased the likelihood of life being discovered on other planets by ten times.

Animal fats and plant oils are sometimes used as sources of fuel for automobile engines. How is energy harvested from these molecules?

They contain long chains of hydrocarbons that, when broken, release the energy stored in the bonds linking the atoms together.

A null hypothesis: a) is the premise that no difference exists between a treatment and control group. b) is the premise that treatment groups were not adequately controlled. c) results from an improperly controlled experiment. d) cannot be rejected. e) is a hypothesis that the experimenter hopes will be falsified.

A null hypothesis: A) is the premise that no difference exists between a treatment and control group. B) is a hypothesis that the experimenter hopes will be falsified. C) cannot be rejected. D) results from an improperly controlled experiment. E) is the premise that treatment groups were not adequately controlled.

A plant with leaves that are reddish yellow is NOT absorbing light from which wavelengths of the visible light spectrum? a) red and yellow b) blue and violet c) green and yellow d) green and red e) green, red, and yellow

A polypeptide chain is a linear polymer of amino acids. Peptide bonds are present between which of the two following groups? a) the carbon atom of the carboxyl group and the nitrogen atom of the amino group b) the carbon atom of the carboxyl group and the adjacent carbon atom of the chain's backbone c) the carbon atom of the carboxyl group and the oxygen atom double-bonded to it d) the carbon atom of the carboxyl group and the OH bound to it e) All of the above are correct.

A powerful way to demonstrate that observed differences between a treatment group and a control group truly reflect the effect of the treatment is for researchers to: a) conduct the experiment over and over again. b) get their study published in a scientific journal. c) use a variety of statistical tests until they find one that shows statistical significance. d) formulate as many hypotheses as they can. e) make more observations.

A solution's acidity is a measure of: a) the H+ (free-floating protons) it contains. b) the number of all dissolved molecules in a solution. c) the number of nucleotide bases in the solution. d) the amount of buffer molecules in the solution. e) its negative charge (the stronger the negative charge, the more acidic the substance).

Active transport, the movement of molecules from areas of low concentration to areas of high concentration across the membrane, is usually coupled to processes that: a) cost energy. b) gain energy for the cell. c) establish a dynamic equilibrium with no net gain or loss in energy for the cell. d) counteract osmotic stress. e) amplify cellular response to signal molecules.

Aerobic bacteria: a) lack mitochondria. b) keep their respiratory enzymes in their nucleus. c) have mitochondria and undergo respiration in the same manner as fungi. d) do not exist. e) Both a and b are correct.

After generating a hypothesis, a scientist next: a) makes a prediction. b) does an experiment. c) formulates a theory. d) writes a grant proposal. e) designs a series of tests.

All of the following are branches of biology EXCEPT: a) geology. b) genetics. c) behavior. d) evolution. e) ecology.

All of the following are components of a single amino acid EXCEPT: A) a pentose sugar. B) a variable side chain. C) a nitrogen-containing amino group. D) a carboxyl group.

Although cells tend to be spherical, several factors influence cells to assume other shapes. Which of the following does NOT influence cell shape? a) number of mitochondria b) cell walls c) structural filaments within the cells d) pressure from neighboring cells e) the cytoskeleton

Although cells tend to be spherical, several factors influence cells to assume other shapes. Which of the following is NOT such a factor? A) number of mitochondria B) structural filaments within the cells C) the cytoskeleton D) pressure from neighboring cells E) cell walls

An experimental condition applied to research subjects is called a: a) treatment. b) control. c) randomization. d) placebo. e) variable.

An unsaturated fatty acid is one in which: a) carbon-carbon double bonds are present in the hydrocarbon chain. b) an odd number of subunits are present in the hydrocarbon chain. c) an even number of subunits are present in the hydrocarbon chain. d) carbon-carbon double bonds are not present in the hydrocarbon chain. e) not all of the carbons in the hydrocarbon chain are bonded to hydrogen atoms.

Anecdotal evidence: a) can appear to reveal links between two phenomena that do not actually exist. b) tends to be more reliable than data based on observations of large numbers of diverse individuals. c) is often the only way to prove important causal links between two phenomena. d) is a more efficient method for understanding the world than the scientific method. e) is a necessary part of the scientific method.

Biologically speaking, a pigment is a: a) molecule that absorbs a photon. b) molecule that releases oxygen. c) molecule that absorbs carbon dioxide. d) cell that absorbs a photon. e) cell that fixes carbon.

Cellular respiration is the process by which: a) energy from the chemical bonds of food molecules is captured by an organism. b) oxygen is produced during metabolic activity. c) ATP molecules are converted into water and sugar. d) light energy is converted into kinetic energy. e) oxygen is used to transport chemical energy throughout the body.

Despite all of the intellectual analyses the scientific method gives rise to and objective conclusions it makes possible, it CANNOT: a) generate moral statements. b) aid in technical advances. c) generate new hypotheses. d) reject false claims. e) affect one's opinions about social issues.

During C4 photosynthesis: a) plants are able to continue producing sugars even when they must close their stomata to reduce water loss during hot days. b) plants are able to produce sugars without any input of carbon dioxide. c) plants are able to generate water molecules to cool their leaves. d) plants are able to reduce water loss by producing more rubisco. e) plants utilize less ATP when producing sugar.

During the Calvin cycle, rubisco's function is to: a) fix carbon to RuBP (ribulose bisphosphate). b) reduce NADPH. c) form RuBP (ribulose bisphosphate) while releasing ATP. d) regenerate RuBP (ribulose bisphosphate) molecules for carbon fixation. e) catalyze the addition of glyceraldehyde 3-phosphate to acetyl-CoA.

During the Krebs cycle: a) the products of glycolysis are further broken down, generating additional ATP and the high-energy electron carrier NADH. b) the products of glycolysis are further broken down, generating additional ATP and the high-energy electron carrier NADPH. c) the products of glycolysis are converted into acetyl-CoA. d) high-energy electron carriers pass their energy to molecules of sugar, which in turn store them as potential energy. e) cellular respiration can continue even in the absence of oxygen.

Energy derived from cellular respiration can originate from: a) carbohydrates, proteins, and fats. b) carbohydrates only. c) carbohydrates and proteins only. d) proteins only. e) fats only.

Fermentation reactions generally occur under conditions of: a) low oxygen concentrations. b) high oxygen concentrations. c) low glucose levels. d) high temperatures. e) low methane concentrations.

Figuratively, the primary structure of proteins is often described as amino acids connected like "beads on a string." In this same vein, which of the following images BEST describes protein quaternary structure? a) threads in a cloth b) coils in a spring c) rungs on a ladder d) needle in a haystack e) links on a chain

Glycogen belongs in the class of molecules known as: a) polysaccharides. b) monosaccharides. c) amino acids. d) proteins. e) nucleic acids.

Glycogen belongs in the class of molecules known as: A) polysaccharides. B) nucleic acids. C) proteins. D) amino acids. E) monosaccharides.

Glycoproteins are membrane proteins with bound: a) carbohydrates. b) nucleic acids. c) signaling peptide sequences. d) phospholipids. e) cofactors.

Helium is not a reactive molecule because its: a) first-level shell is full with two electrons. b) first-level shell is full with two protons. c) second-level shell is full with two electrons. d) first-level shell is full with two neutrons. e) Helium is a reactive molecule.

How are phospholipid molecules that make up the surface membrane of a cell organized? a) A two-layered structure is formed, with the hydrophobic tails facing in to each other, sandwiched between the hydrophilic heads that face the interior of the cell and the exterior environment. b) A single-layered structure is formed, with the hydrophobic tails facing in to the interior of the cell and the hydrophobic head on the outside, facing the exterior environment. c) A single-layered structure is formed, with the hydrophobic heads facing in to the interior of the cell and the hydrophobic tails on the outside, facing the exterior environment. d) A two-layered structure is formed, with the hydrophobic heads facing in to each other, sandwiched between the hydrophilic tails on the outside that face interior of the cell and the exterior environment. e) Both b and d are possible.

How many hydrogen bonds are explicitly represented in this figure? A) 4 B) 8 C) 1 D) 0 E) 10

If a report states, "The female subjects in the study are 5 feet 6 inches ± 3 inches," this indicates that: a) two-thirds of the women are between 5 feet 3 inches and 5 feet 9 inches. b) all of the women are between 5 feet 3 inches and 5 feet 9 inches. c) 90% of the women are between 5 feet 3 inches and 5 feet 9 inches. d) the variation among women is 3 inches in height. e) the investigator is unsure of her data.

If the solution surrounding a cell contains less solute than the cytoplasm, the osmotic condition is said to be: a) hypotonic. b) hypertonic. c) isotonic. d) isobaric. e) adiabatic.

If you toss a coin and it comes up tails on eight consecutive tosses, what is the likelihood it will come up heads on the ninth toss? a) 1/2 b) 4/9 c) 5/9 d) 1 e) 0

If your hypothesis is "Echinacea reduces the duration and severity of the common cold," which of the following is the BEST testable prediction for this hypothesis? a) If echinacea reduces the duration and severity of the symptoms of the common cold, then individuals taking echinacea should get sick less frequently than those not taking it, and when they do get sick, their illness should not last as long. b) If echinacea reduces the duration and severity of the symptoms of the common cold, then individuals taking echinacea should get sick less frequently than those not taking it. c) If echinacea reduces the duration and severity of the symptoms of the common cold, then individuals taking echinacea who get sick should have illness that does not last as long. d) If echinacea reduces the duration and severity of the symptoms of the common cold, then individuals taking echinacea should get sick more frequently than those not taking it, and when they do get sick, their illness should last longer. e) None of the above is a reasonable testable prediction for this hypothesis.

If your hypothesis is "Estrogens in sewage runoff turn fish into hermaphrodites," what is your null hypothesis? a) Estrogens in sewage runoff have no effect in turning fish into hermaphrodites. b) Estrogens in sewage runoff turn turtles into hermaphrodites. c) Estrogens in sewage runoff turn hermaphroditic fish into unisexual fish. d) Testosterones in sewage runoff turn fish into hermaphrodites. e) Testosterones in sewage runoff have no effect in turning fish into hermaphrodites.

In DNA, adenine from one strand binds to ______ in the complementary strand. a) thymine b) adenine c) uracil d) cytosine e) guanine

In a randomized, controlled, double-blind study: a) neither the experimenter nor the subject know whether the subject is in a control group or an experimental group. b) individuals will be assigned to an experimental or control group depending on whether or not they took part in a pilot study. c) experimental subjects are blindfolded when given the experimental treatment. d) all experimental variables are held constant. e) All of the above.

In eukaryotic cells, vesicles connect which of the two major organelle compartments? a) the rough endoplasmic reticulum and smooth endoplasmic reticulum b) the rough endoplasmic reticulum and nucleus c) the smooth endoplasmic reticulum and the peroxisomes d) the rough endoplasmic reticulum and the centrioles e) the rough endoplasmic and the ribosomes

Interacting systems of molecules enclosed in compartments called __________ evolved 3.8 billion years ago in living organisms. a) cells b) organs c) microspheres d) brains e) circulatory systems

Nuclear ______ are specialized holes in the ________-layered nuclear envelope that separates the nucleus from the ___________. a) pores; two; cytoplasm b) passageways; one; cytoplasm c) vesicles; three; endoplasmic reticulum d) pores; one; endoplasmic reticulum e) vesicles; two; cytoplasm

On food packages, "insoluble fiber" refers to plant material that we can't fully digest but is important for maintaining a healthy digestive tract. This substance refers to a(n): A) carbohydrate. B) protein. C) nucleic acid. D) amino acid. E) lipid.

Once a scientist has formulated a hypothesis that generates a testable prediction, she will: a) conduct a critical experiment. b) formulate a second hypothesis. c) make observations. d) draw conclusions. e) make revisions.

Osmosis is (MORE or LESS, pick one) specialized than diffusion because it involves _________. a) more; water b) less; all liquids c) more; acids d) less; acids e) more; bases

Phosphate groups are important components of: a) nucleic acids. b) structural polysaccharides. c) amino acids. d) triglycerides. e) All of the above are correct.

Phospholipids assemble spontaneously into bilayers driven by the attraction of their "tail" portions to each other and of their "head" portions to each other. The tail regions are: a) hydrophobic. b) cohesive. c) molecularly charged. d) adhesive. e) hydrophilic.

Photosynthesizing plants rely on water to: a) replace electrons that are excited by light energy and passed from molecule to molecule down an electron transport chain. b) replenish oxygen molecules that are lost during photosynthesis. c) provide the protons necessary to produce chlorophyll. d) concentrate the beams of light hitting a leaf, focusing them on the reaction center. e) serve as a high-energy electron carrier.

Photosystems are: a) arrangements of light-catching pigments within chloroplasts. b) arrangements of chloroplasts within the cells lining the surface of leaves. c) the wavelengths of light that reach the earth from the sun. d) arrangements of thylakoid membranes within the plant cell wall. e) arrangements of ATP-synthase molecules within chloroplasts.

Plants have cell walls to give them more structural strength. In order to facilitate movement of molecules from one plant cell to another, channels called ___________________ run through the cell walls. a) plasmodesmata b) plasma membranes c) vacuoles d) transport vesicles e) desmosomes

Science as a way of seeking principles of order differs from art, religion, and philosophy in that: a) science deals exclusively with known facts. b) science limits its search to the natural world of the physical universe. c) all scientific knowledge is gained by experimentation. d) science denies the existence of the supernatural. e) there is no room for intuition or guessing.

Science is self-correcting. This means that: a) science actively seeks to disprove its own theories and hypotheses. b) science is incapable of producing mistaken beliefs if its studies are carefully done. c) scientists correct their own biases before engaging in scientific study. d) when scientists make mistakes in their statistical analyses, their statistical software always catches those mistakes. e) scientists have impeccable manners.

Scientific study always begins with: a) observations. b) conclusions. c) hypotheses. d) predictions. e) experiments.

Scientific theories do not represent speculations or guesses about the natural world. Instead, they are hypotheses—proposed explanations for natural phenomena—that have been: a) so strongly and persuasively supported by empirical observation that the scientific community views them as unlikely to be altered by new evidence. b) verified by at least one critical experiment. c) validated by the International Board of Scientific Theories. d) used to support the political stances of the scientists who have developed them. e) found to be statistically significant.

Statistical methods make it possible to: a) determine how likely it is that certain results may have occurred by chance. b) choose the best answer to value-based questions. c) reject any hypothesis. d) unambiguously learn the truth. e) test non-falsifiable hypotheses.

Superstitions are: a) irrational beliefs that actions not logically related to a course of events influence its outcome. b) held by some humans but not by any non-human species. c) true beliefs that have yet to be fully understood. d) proof that the scientific method is not perfect. e) just one of many possible forms of scientific thinking.

The cell connections represented above are: a) desmosomes. b) tight junctions. c) gap junctions. d) plasmodesmata. e) lysosomes.

The diagram above represents which class of chemical compounds? a) sterols b) proteins c) carbohydrates d) acids e) fats

The fact that water is less dense as a solid than as a liquid explains why: a) ice floats on top of liquid water. b) water is such a good solvent. c) water can resist temperature changes. d) ice cubes sink when placed in a glass of water. e) oil never dissolves in water.

The most abundant protein in the world is the enzyme that initiates the fixation of carbon in the Calvin cycle. This enzyme is called: a) rubisco. b) glyceraldehyde 3-phosphate. c) ATP-synthase. d) ribulose biphosphate. e) crassulacean acid.

The net movement of molecules from locally concentrated regions to uniform distributions is best described as: a) diffusion. b) concentration gradient. c) active transport. d) passive transport. e) enthalpy.

The net movement of molecules from locally concentrated regions to uniform distributions is best described as: A) diffusion. B) passive transport. C) active transport. D) concentration gradient. E) enthalpy.

The placebo effect: a) is the frequently observed, poorly understood, phenomenon that people tend to respond favorably to any treatment. b) reveals that sugar pills are generally as effective as actual medications in fighting illness. c) is an urban legend. d) reveals that experimental treatments cannot be proven as effective. e) demonstrates that most scientific studies cannot be replicated.

The primary function of molecular membranes is the transport of ions and molecules into and out of cells. The movement of molecules from areas of low concentration to those of high concentration against chemical gradients is best described as: a) active transport. b) passive transport. c) inactivated transport. d) channel-mediated diffusion. e) electron transport.

The primary function of molecular membranes is the transport of ions and molecules into and out of cells—transport is directional and selective. The movement of molecules from areas of high concentration to areas of low concentration to gain energy is best described as: a) passive transport. b) active transport. c) inactivated transport. d) channel-mediated diffusion. e) electron transport.

The principal components of cell membranes are: a) lipids. b) proteins. c) carbohydrates. d) nucleic acids. e) glycoproteins.

The proposed explanation for a phenomenon is BEST described as: A) a hypothesis. B) an experiment. C) a testable prediction. D) a theory. E) an observation.

The raw materials of science are: a) observations. b) hunches. c) predictions. d) theories. e) hypotheses.

To absorb large particles, cells engulf them within their plasma membrane in a process called: A) endocytosis. B) translation. C) replication. D) transcription. E) exocytosis.

What is the main function of the nucleolus? A) It is the site of ribosome-subunit synthesis. B) It is the site of photosynthesis in photosynthetic cells. C) Its function is not yet known. D) It produces enzymes that are then exported to the lysosomes. E) It produces cell adhesion proteins that are then exported to the cell membrane.

What should you do when something you believe turns out to be wrong? a) Change your mind. b) Feel ashamed. c) Blame the government. d) Hold to your beliefs. e) Doubt your ability to properly perceive the sensory stimuli of the world

When energy is converted from one form to another: a) some energy is converted to heat. b) a small amount of energy is destroyed. c) a small amount of energy is created. d) the quantity of energy in the universe changes. e) it becomes more useful to organisms for fueling cellular activity.

Which by-product of photosynthesis was important in altering the atmosphere of the earth so that aerobic organisms could evolve? a) oxygen b) carbon dioxide c) nitrogen d) methane gas e) air

Which cellular structure makes it possible for a cell to differ structurally and biochemically from its surroundings? a) plasma membrane b) nucleolus c) nucleus d) endoplasmic reticulum e) cell wall

Which of the following BEST defines diffusion? a) net movement of particles from areas of high concentration to areas of low concentration b) net movement of particles from areas of low concentration to areas of high concentration c) net movement of particles between cells d) net movement of particles from a cell into the extracellular matrix e) net movement of fluids from the environment into and out of an organism

Which of the following does NOT occur as a direct result of a photon hitting a chlorophyll molecule? a) production of NADPH and H+ b) excitation of an electron c) fluorescence d) a release of heat e) backward reflection of the photon

Which of the following energy-generating processes is the only one that occurs in all living organisms? a) glycolysis. b) gluco-neogenesis. c) the Krebs cycle. d) photophosphorylation. e) None of the above; no energy-generating processes occur in all living organisms.

Which of the following is MOST correct? a) You can accept or reject a hypothesis, but never prove it to be true. b) You can prove a hypothesis to be true. c) You can prove a hypothesis to be false. d) Accepting or rejecting a hypothesis is the same as proving whether or not the hypothesis is true. e) By rejecting a hypothesis, you also reject any theory that was correlated with that hypothesis

Which of the following is a cellular characteristic of ALL eukaryotes? a) a nuclear membrane b) a cell wall c) a nucleoid d) few to no organelles in the cytoplasm e) few to no proteins associated with the DNA

Which of the following is a correct description of how exocytosis functions in transporting molecules across the cellular membrane? a) Vesicles are filled with molecules in the interior of the cell and then fuse with the membrane to deposit the molecules outside of the cell. b) Protein molecules on the interior of the cellular membrane trap molecules attached on the exterior side and bring them into the cell. c) Nutrients are moved within the cell from one tightly woven network to another. d) A receptor protein on the outside of the cell binds a particular biochemical, causing the membrane to form an indentation, bringing the biochemical into the cell. e) None of the above is correct.

Which of the following is found in both prokaryotic and eukaryotic cells? a) ribosome b) centriole c) Golgi apparatus d) peroxisome e) lysosome

Which of the following is the BEST description of a control group in an experiment? a) The control group is identical to each test group, except for one variable. b) The control group and the test groups may have several differences between them. c) There can be more than one difference between the control group and test groups, but not several differences or else the experiment is invalid. d) There should be more than one control group in any experiment. e) The control group is a test group that is chosen at random.

Which of the following is usually employed before the others by an investigator using the scientific method? a) Make observations. b) Formulate a hypothesis. c) Devise a testable prediction. d) Conduct a critical experiment. e) Analyze data.

Which of the following questions CANNOT be answered by the scientific method? A) Did the United States act appropriately when it invaded Iraq? B) Does taking echinacea reduce the intensity or duration of the common cold? C) Is eyewitness testimony is criminal proceedings reliable? D) Does hair that is shaved grow back coarser? E) Does chemical runoff give rise to hermaphrodite fish?

Which of the following questions would be LEAST helped by application of the scientific method? a) formulating public policy on euthanasia b) comparing the effectiveness of two potential antibiotics c) developing more effective high school curricula d) determining the most effective safety products for automobiles e) evaluating the relationship between violence in video games and criminal behavior in teens

Which of the following sequences accurately represents the flow of electrons during photosynthesis? a) H2O → NADPH → Calvin cycle b) NADPH → O2 → CO2 c) NADPH → chlorophyll → Calvin cycle d) H2O → ATP → Calvin cycle e) NADPH → electron transport chain → O2

Which of the following statements BEST explains the observation that more autism cases exist now than in the past? a) Doctors are more aware of the condition and have better techniques for diagnosing and reporting it. b) More parents neglect their children, which is a cause of autism, now than in the past. c) The vaccine for measles, mumps, and rubella has been established as a significant cause of autism. d) Autism has been selected for in recent generations by natural selection. e) All of the above are equally good explanations for the observation that more autism cases exist now than in the past.

Which of the following statements about fiber is FALSE? a) Fiber in the diet slows the passage of food through the intestines. b) The cellulose of celery stalks and lettuce leaves is fiber. c) Fiber passing through the digestive system scrapes the wall of the digestive tract, stimulating mucous secretion, and aiding in the digestion of other molecules. d) Humans are unable to extract any caloric value from fiber. e) Dietary fiber reduces the risk of colon cancer.

Which of the following terms and phrases best describes the application of scientific knowledge to specific purposes? a) technology b) statistics c) deduction d) junk science e) pseudoscience

Which statement about phospholipids is FALSE? A) Because their phosphate groups repel each other, they are used as organisms' chief form of short-term energy. B) They are a major constituent of cell membranes. C) They are hydrophobic on one end. D) They are hydrophilic at one end.

Which statement is NOT part of the modern cell theory? a) The first cell arrived on earth from outer space. b) All living organisms consist of one or more cells. c) Cellular reactions include both energy-releasing and biosynthetic types. d) Cells arise from other cells. e) Cells contain hereditary information that passes from one generation of cells to the next.

Which type of macromolecule is an informational molecule? A) DNA B) protein C) monosaccharide D) polysaccharide E) fatty acid

Why do coastal areas have milder, less variable climates than inland areas? A) Large bodies of water, especially oceans, can absorb huge amounts of heat from the sun during warm times of the year, reducing temperature increases on the land. Similarly, during cold times of year the ocean slowly cools, giving off heat that reduces the temperature drop on shore. B) Large bodies of water have high salt concentrations and salt absorbs a large proportion of the light energy that would have warmed the land. C) Because water is a good solvent, it is able to dissolve the photons in light, reducing their ability to heat or cool the land. D) Coastal areas are concentrated near the equator, which varies less than other parts of the globe in the angle at which the sun's light hits it. E) None of the above. No one knows why coastal areas have milder, less variable climates than inland areas.

Within the study of thermodynamics, a closed system is defined as system in which energy does not come in and energy does go out. Which of the following is considered a closed system? a) the universe b) the earth c) an ocean d) a living organism's body e) All of the above are examples of closed systems.

You are bored at a lunch meeting and surreptitiously place a raisin in your glass of water. The raisin swells to twice its original size. Relative to the water, the raisin must have been: a) hypertonic. b) osmotic. c) hypotonic. d) isotonic. e) mesotonic.

You note a fuzzy growth on some of the gels in your incubator. What is the name given to this step of the scientific method? a) observation b) hypothesis c) law d) theory e) confirmation

______________ are found in all metabolically active cells and are involved primarily in transporting materials within, into, and out of cells. a) Vesicles b) Lysosomes c) Vacuoles d) Peroxisomes e) Ribosomes

A partial sequence of a molecule is "AACTGCT." The molecule is:

a nucleic acid.

An amino acid is to a polypeptide as:

a nucleotide is to a nucleic acid.

A cell's interior is considered isotonic to the surrounding fluid when: A) the solute concentration is lower within the cell than outside the cell. B) the solute concentrations are the same within and outside the cell. C) the cell's lipid bilayer does not allow any molecules to pass into or out of the cell. D) there is an equal number of water molecules immediately outside the cell as inside the cell. E) the solute concentration is higher within the cell than outside the cell.

A complex polymer built of amino acids is called a(n): a) monosaccharide. b) polypeptide. c) fatty acid. d) polysaccharide. e) amine.

All lipids are: a) triglycerides. b) not soluble in water. c) polar. d) hydrophilic. e) polymers of fatty acids.

An amino acid is to a polypeptide as: a) glycogen is to glucose. b) a nucleotide is to a nucleic acid. c) a phospholipid is to a plasma membrane. d) a nucleic acid is to DNA. e) testosterone is to a steroid hormone.

Approximately 70−90% of the genetic material in a gamete made in your body could be inherited from your mother. How could this be? a) The X chromosome is substantially larger than the Y chromosome. b) You receive many mitochondria, which have their own genome, from your mother, but not from your father. c) Your maternal genes kill off your paternal genes at a greater rate than your paternal genes kill of your maternal genes. d) You receive maternal genes through the placenta and through breast milk. e) The above statement is incorrect, because 50% of the genetic material in your gametes comes from your father.

Biology is ________. a) mostly a collection of facts that can be ordered and memorized b) the study of living things c) always used responsibly in advertising claims d) a separate branch of science from the study of how organisms interact with each other and with their environment e) Both a and b.

Biology is to science as ________ is to ________. a) baseball; tennis b) basketball; sports c) American soccer; European football d) college baseball; professional baseball e) the home team; the visiting team

Carotenoids: a) are the stacks of thylakoid membranes in a chloroplast. b) are more abundant in leaves in the fall than either chlorophyll a or b. c) absorb red, orange, and yellow wavelengths of light. d) reflect blue-green and blue-violent wavelengths of light. e) are the site of photosynthesis in a plant cell.

Chlorophyll's most important role during photosynthesis is: a) keeping the leaves of plants green. b) converting light energy from the sun into chemical energy. c) capturing electrons that can, in turn, be used by carotenoids. d) turning color in the autumn each year. d) turning into a molecule of ATP upon being struck by sunlight.

Energy is released as ATP becomes ADP when: a) ATP ejects ribose. b) ATP ejects one of its phosphate groups. c) ATP ejects two of its phosphate groups. d) ATP ejects adenine. e) ATP ejects three of its phosphates.

Enzymes: a) sometimes increase the amount of energy necessary to initiate a reaction. b) increase the rate at which a reaction occurs. c) catalyze reactions that release energy, but not those that consume energy. d) are always consumed by catalyzing a reaction. e) reduce the energy released by a reaction by one of four different mechanisms.

Evaporation from the leaves of a tree will pull water up through the roots as an unbroken column throughout the entire height of the tree. This feat is possible because of which characteristic of water? a) surface tension b) cohesion c) absorption d) kinetic energy e) vaporization

Given that a cell's structure reflects its function, what would you predict that the function of a cell with a large Golgi apparatus would be? a) movement b) secretion of digestive enzymes c) transport of chemical signals d) rapid replication of genetic material and coordination of cell division e) attachment to bone tissue

Helium is not a reactive molecule because: A) its second-level shell is full with two electrons. B) its first-level shell is full with two electrons. C) its first-level shell is full with two neutrons. D) its first-level shell is full with two protons.

Human sex hormones are classified as which type of biological molecule? a) enzyme b) lipid c) nucleic acid d) protein e) carbohydrate

If a thylakoid were punctured so that its interior was no longer separated from the stroma, which of the following processes would be affected most directly? a) NADPH oxidation b) ATP synthesis c) flow of electrons from photosystem I to photosystem II d) the splitting of water e) chlorophyll's energy absorption

If the results of an experiment turn out differently from what you expected, then: a) your experiment was a failure. b) you should explore the reasons for this in the "conclusions" section of your experimental write-up. c) you need to redo your experiment until you get the expected result. d) you didn't follow the scientific method. e) your instruments were probably at fault.

If your hypothesis is "Estrogens in sewage runoff turn fish into hermaphrodites," what is your null hypothesis? A) Testosterones in sewage runoff turn fish into hermaphrodites. B) Estrogens in sewage runoff have no effect in turning fish into hermaphrodites. C) Estrogens in sewage runoff turn hermaphroditic fish into unisexual fish. D) Estrogens in sewage runoff turn turtles into hermaphrodites. E) Testosterones in sewage runoff have no effect in turning fish into hermaphrodites.

In DNA, adenine from one strand binds to ______ in the complementary strand. A) guanine B) thymine C) uracil D) cytosine E) adenine

In a recent study, patients treated with a genetically engineered heart drug were able to walk on a treadmill for 26 seconds longer than those not receiving the drug and showed no side effects. Can we conclude that this drug is an effective treatment for heart disease? a) Yes. b) No. It is not clear that the proper controls were made. c) No. It is not clear that the drug is not a placebo. d) No. It is not clear how many subjects were in the study. e) No. Genetically engineered drugs cannot be tested via the scientific method. They require comparative observations.

Energized electrons from the water-splitting photosystem pass down an electron transport chain to the ___________-producing photosystem. a) NADP+ b) O2 c) NADPH d) H2O e) ATP

In a scientific experiment, a control group: A) is less important than an experimental group. B) can be compared with an experimental group to assess whether one particular variable is causing a change in the experimental group. C) must be kept in a laboratory. D) makes the experiment better, but is not essential. E) All of the above are correct.

In aquatic environments, water moves _____________. a) up the concentration gradient b) down the concentration gradient c) down the concentration scale d) up the concentration scale e) against the concentration gradient

In controlled experiments: a) all variables are held constant. b) one variable is manipulated, while others are held constant. c) all critical variables are manipulated. d) all variables are dependent on each other. e) all variables are independent of each other.

On food packages, "insoluble fiber" refers to plant material that we cannot fully digest but is important for maintaining a healthy digestive tract. This substance refers to a(n): a) nucleic acid. b) carbohydrate. c) protein. d) lipid. e) amino acid.

One important difference between covalent and ionic bonds is that: A) ionic bonds only occur among water-soluble elements. B) in covalent bonds two atoms share electrons while in ionic bonds two atoms of opposite charge are attracted to each other. C) in ionic bonds two atoms share electrons while in covalent bonds one atom gives one or more electrons to the other atom. D) ionic bonds are much stronger than covalent bonds. E) in ionic bonds both protons and electrons can be shared while in covalent bonds only electrons can be shared.

One of the four nucleotide bases in DNA is replaced by a different base in RNA. Which base is it, and what is it replaced by? a) adenine, replaced by uracil b) thymine, replaced by uracil c) guanine, replaced by cytosine d) thymine, replaced by guanine e) cytosine, replaced by guanine

Phospholipids assemble spontaneously into bilayers driven by the attraction of their "tail" portions to each other and of their "head" portions to each other. The tail regions are: A) cohesive. B) hydrophobic. C) adhesive. D) hydrophilic. E) molecularly charged.

Photosynthesis is the process by which plants, some bacteria, and some protistans use the energy from sunlight to produce sugar, which _______________ converts to ATP, the "fuel" used by all living things. a) eutrophication b) cellular respiration c) adaptation d) denaturation e) speciation

Prokaryotic organisms lack: A) metabolism. B) a nucleus C) replicator molecules (DNA or RNA). D) cell membranes. E) All of the above.

Pseudoscience capitalizes on the belief shared by most people that: a) the scientific bases for scientific-sounding claims are often not clear. b) scientific thinking is a powerful method for learning about the world. c) scientific thinking is beyond the reach of the average person. d) science is intimidating. e) scientific claims can be evaluated through the political process.

Pure water has a pH of 7.0. Cola has a pH of about 3.0. That means cola is: a) 10,000 times more basic than water. b) 10,000 times more acidic than water. c) about 40 times more acidic than water. d) about 40 times more basic than water. e) about 4 times more acidic than water.

Relative to protons, electrons have: a) significantly greater mass. b) significantly less mass. c) approximately the same mass. d) a significantly stronger positive charge. e) None of the above is correct. Electrons have no mass.

Scientific data: a) must be collected in laboratories. b) are used to support or refute a hypothesis. c) cannot be collected in a completely unbiased way. d) are always true. e) All of the above are true.

Secretion of cell products such as milk proteins and mucus from glandular cells is accomplished via: a) passive transport. b) exocytosis. c) active transport. d) facilitated diffusion. e) endocytosis.

Sucrose (table sugar) and lactose (the sugar found in milk) are examples of: a) simple sugars. b) disaccharides. c) monosaccharides. d) naturally occurring enzymes. e) polyunsaccharide sugars.

The figure shows the action of beta-blockers in reducing anxiety. In this diagram, the triangular wedges represent ________________, the figures with rectangular tops and triangular bottoms represent ______________, and the ovals represent ______________. A) adrenaline; beta-receptors; beta-blocker chemicals B) adrenaline; beta-blocker chemicals; beta-receptors C) beta-blocker chemicals; mucus; beta-receptors D) beta-blocker chemicals; adrenaline; beta-receptors E) mucus; beta-blocker chemicals; beta-receptors

The four most abundant elements in living organisms are: A) carbon, hydrogen, nitrogen, and phosphorus. B) hydrogen, nitrogen, oxygen, and carbon. C) carbon, nitrogen, oxygen, and calcium. D) sodium, nitrogen, carbon, and silicon. E) carbon, nitrogen, potassium, and oxygen.

The largest structure in a eukaryotic cell is the ____________ and it is surrounded by ______ membranes. A) mitochondrion; two B) nucleus; two C) nucleus; one D) Golgi apparatus; one E) mitochondrion; one

The largest structure in a eukaryotic cell is the ____________, and it is surrounded by ______ membranes. a) nucleus; one b) nucleus; two c) Golgi apparatus; one d) mitochondrion; two e) mitochondrion; one

The object pictured above: a) is a plant cell. b) is an animal cell. c) could be either a plant or animal cell. d) is a bacterial cell. e) is a ribosome.

The passive transport of water across a membrane from a solution of lower solute concentration to a solution of higher solute concentration is best described as: a) facilitated diffusion. b) osmosis. c) passive transport. d) active transport. e) general diffusion.

The proposed explanation for a phenomenon is BEST described as: a) an observation. b) a hypothesis. c) a testable prediction. d) an experiment. e) a theory.

Eukaryotic cells may contain all of the following EXCEPT: a) photosynthetic pigments. b) flagella. c) a peptidoglycan cell wall. d) ribosomes. e) a membrane-bound nucleus.

The tendency of molecules to stick together, called cohesion, is stronger in water than in other liquids because: A) the polarity of water allows a hydrogen atom from one water molecule to form a hydrogen bond with the hydrogen atom of another water molecule. B) the polarity of water allows a hydrogen atom from one water molecule to form a hydrogen bond with the oxygen atom of another water molecule. C) the polarity of water allows a hydrogen atom from one water molecule to form an ionic bond with the oxygen atom of another water molecule. D) the polarity of water allows a hydrogen atom from one water molecule to form a covalent bond with the oxygen atom of another water molecule. E) the polarity of water allows an oxygen atom from one water molecule to form a hydrogen bond with the oxygen atom of another water molecule.

The three different known biochemical pathways organisms will use to photosynthesize include which of the following? a) C3, C4, C5 b) C3, C4, CAM c) C4, C5, CAM d) C3, C5, CAM e) C2, C4, CAM

Thinking scientifically relies on which of the following? a) intuition b) objective observation and experimentation c) statements from authorities d) learning a list of facts e) applying your preconceptions

Vesicles: a) deposit their protein cargo in an arbitrary fashion throughout the cell. b) bud off from the endoplasmic reticulum. c) fuse with the nucleus membrane to deliver important enzymes, such as polymerase. d) return back to the Golgi apparatus after they have delivered their proteins to be reused. e) Both b and d are correct.

Water molecules form which type of bond with other water molecules? A) ionic bonds B) hydrogen bonds C) disulfide bridges D) covalent bonds E) Van der waals bonds

What are the three different metabolic pathways that are responsible for the production of ATP? a) substrate inhibition, catabolism, and fermentation b) glycolysis, the reactions on the electron transport chain, and the Krebs (citric acid) cycle c) hydrolysis, active transport, and the light reactions d) glycolysis, oxidation, and the Calvin cycle reactions e) None of the above is correct.

What is the best way for a scientist to address his/her own biases? a) Make sure that no biases influence his/her work. b) Use careful controls to minimize them. c) Understand his/her biases and interpret the data differently as a result. d) Never be involved in any kind of scientific study where his/her possible biases might impact the study. e) None of the above is correct; there is no way a scientist can deal with biases.

What is the most important barrier protecting the inner contents of an animal cell with its exterior environment? a) the cell wall b) the cellular membrane c) the cytoskeleton d) the nucleus e) Both a and b are correct.

What makes the rough endoplasmic reticulum rough? a) It is covered with cilia. b) It is covered with ribosomes. c) Its surface is highly folded to increase surface area. d) It is covered with tiny flagella. e) It has a high density of receptor proteins in its membrane.

When conducting a scientific experiment, which of the following is tested? a) an observation b) a prediction c) a result d) a question e) the null variable

Where does the Calvin cycle take place? a) in the cellular cytoplasm b) in the stroma of the chloroplast c) in the thylakoid membrane d) around the chlorophyll molecule e) in the Hobbesian membrane

Which of the following BEST summarizes the differences between osmosis and diffusion? a) Osmosis deals only with acidic liquids. b) Osmosis deals only with water. c) Osmosis deals only with alkaline liquids. d) Diffusion deals only with alkaline liquids. e) Diffusion deals only with water.

Which of the following are all monosaccharides? a) glucose and maltose b) glucose, fructose, and galactose c) fructose and cellulose d) glycogen and glucose e) starch, cellulose, and glycogen

Which of the following are all monosaccharides? A) glycogen and glucose B) glucose, fructose, and galactose C) glucose and maltose D) starch, cellulose, and glycogen E) fructuse and cellulose

Which of the following cell membrane components are present in plant cells but absent in animal cells? a) phospholipids b) plasmodesmata c) gap junctions d) proteins e) carbohydrates

Which of the following is NOT true of ALL cells? a) They assimilate nutrients. b) They move by means of flagella or cilia. c) They eliminate wastes. d) They synthesize new cellular material. e) They have DNA as their genetic material.

Which of the following is a polysaccharide? a) insulin, the chief blood sugar regulator b) cellulose, the primary component of plant cell walls c) fructose, one of the most important blood sugars d) glucose, the chief cellular energy source e) All of the above are polysaccharides.

Which of the following is the BEST way to state the relationship between "data" and "results"? a) "Data" and "results" are two names for the same thing. b) "Data" are the facts you collect from your experiment, while "results" are your interpretation of what the data mean. c) Any two scientists examining the same "data" would draw the same "results." d) The "data" section should always come before the "results" section in a scientific paper. e) Any two scientists reporting the same "results" must have been using the same "data."

Which of the following molecules is NOT formed by covalent bonding? a) H2O b) NaCl c) CH4 d) O2 e) H2

Which of the following organelles are enclosed by a double membrane? a) the nucleus and the Golgi apparatus b) mitochondria and chloroplasts c) ribosomes and lysosomes d) vacuoles and the endoplasmic reticulum e) All organelles are enclosed by a double membrane.

Which of the following organelles is responsible for degrading waste within the cell? a) Golgi apparatus b) lysosome c) endoplasmic reticulum d) ribosome e) chloroplast

Which of the following statements about glycolysis is INCORRECT? a) It occurs in the cytoplasm of the cell. b) It requires oxygen. c) It results in the oxidation of glucose. d) It generates ATP. e) It leads to the formation of pyruvate.

Which of the following statements about the DIFFERENCES between the chlorophyll a molecule at the center of a photosystem and chlorophyll elsewhere in the photosystem is NOT true? a) The excited electrons in chlorophyll a not at the photosystem center return to their resting state, while the excited electrons in the reaction center chlorophyll a are transferred to the primary electron acceptor. b) The excited electrons in chlorophyll a at the reaction center return to their resting state, while the excited electrons in chlorophyll a away from the photosystem center are transferred to the primary electron acceptor. c) Electrons in chlorophyll a at the photosystem center are replaced by splitting water, while electrons in the other chlorophyll molecules do not need to be replaced. d) Chlorophyll outside of the photosystem center can transfer energy to any number of other molecules, while chlorophyll a at the center of the photosystem center transfers its electron to only one other molecule. e) There are fewer copies of chlorophyll a in the photosystem center than there are copies of chlorophyll outside of the photosystem center.

Which of the following would be a typical product of the dark reactions of photosynthesis? a) ethanol b) 3-phosphoglycerate acid (3-PGA) c) green fluorescent protein d) FADH2 e) pyruvate

Which type of macromolecule is an informational molecule? a) monosaccharide b) DNA c) protein d) polysaccharide e) fatty acid

You measure the concentration of a polar molecule inside and outside of a cell. You find that the concentration is high and gradually increasing inside the cell. You also measure the ATP concentration inside the cell and find that it is dropping. Your best hypothesis for the process that is occurring would be: a) facilitated diffusion. b) active transport. c) passive transport. d) simple diffusion. e) endocytosis.

Biology is to science as ________ is to ________.

basketball, sports

In the diagram above, the red slashed circle represents:

beta-blockers preventing adrenaline from binding with beta-receptors.

"Beta-blockers" do all of the following EXCEPT: A) reduce the effects of adrenaline on the heart. B) reduce outward symptoms of anxiety. C) bind to the cytoplasmic side of a receptor protein. D) block signaling through adrenaline receptors. E) reduce high blood pressure.

A cell's interior is considered isotonic to the surrounding fluid when: a) the solute concentration is higher within the cell than outside the cell. b) the solute concentration is lower within the cell than outside the cell. c) the solute concentrations are the same within and outside the cell. d) an equal number of water molecules is present immediately outside the cell as inside the cell. e) the cell's lipid bilayer does not allow any molecules to pass into or out of the cell.

A partial sequence of a molecule is "AACTGCT." The molecule is A) a polypeptide. B) a triglyceride. C) a nucleic acid. D) a polysaccharide. E) a protein.

According to the theory of endosymbiosis, the origin of chloroplasts probably involved: a) the formation of colonies of cyanobacteria. b) the formation of cell walls around the photosynthetic pigments. c) engulfing of small photosynthetic prokaryotes by a larger cell. d) the accumulation of free oxygen in ocean waters. e) All of the above are correct.

According to the theory of endosymbiosis, the origin of chloroplasts probably involved: A) the formation of cell walls around the photosynthetic pigments. B) the formation of colonies of cyanobacteria. C) engulfing of small photosynthetic prokaryotes by larger cells. D) the accumulation of free oxygen in ocean waters. E) All of the above are correct.

All alcoholic beverages are produced as the result of cellular respiration: a) by bacteria occurring in the absence of oxygen. b) by yeast occurring in the absence of free electrons. c) by yeast occurring in the absence of oxygen. d) by bacteria occurring in the absence of free electrons. e) occurring in the absence of sugar.

All macromolecules important in living systems contain: A) aldehydes. B) carbon. C) polymers. D) nitrogen. E) potassium.

An inherited disease results from abnormal mitochondria passed from mother to child. Using your knowledge of mitochondria's function within human cells, which of the following is the most likely description of the symptoms of this disease? a) extreme sensitivity to UV light, resulting in skin cancer at a very young age b) inability to absorb iron, resulting in extreme anemia c) extreme muscle weakness d) fragile bones and arthritis e) color blindness

Bubbles come from the leaves of an elodea plant when it is put under water because: a) oxygen and carbon dioxide diffuse out of vacuoles when vacuole pressure is reduced. b) the cell wall is permeable to the gases released by the stomata. c) oxygen is a by-product of photosynthesis. d) thylakoids become depressurized and release nitrogen gas. e) due to anaerobic conditions under water, the plant must resort to fermentation, causing the production of excess carbon dioxide.

Chlorophyll b and the carotenoids are important as receptors of light energy because they: a) can absorb green light. b) have their own photosystems. c) respond to wavelengths different from the wavelengths to which chlorophyll a responds. d) can respond to infrared and ultraviolet light. e) transform this energy into chemical energy.

DNA is made of: A) four interconnected carbon rings. B) amino acids. C) nucleotides. D) glucose molecules. E) fatty acids.

Suppose you measure the height of two people. One is a woman who is 5 feet 10 inches tall. The other is a man who is 5 feet 6 inches tall. Which of the following is an appropriate conclusion to draw from these measurements? A) Men are taller than women. B) Women are taller than men. C) Some women are taller than some men. D) The tallest woman is 5 feet 10 inches tall. E) Some men are taller than some women.

The C4 mechanism of carbon fixation is an advantage for plants that live in: a) ponds or other bodies of fresh water. b) the shade of other plants. c) hot, dry climates. d) swamps or bogs. e) cool climates.

The graphs above show data relating to seasonal differences in the amount of pigment molecules present in leaves and how this is related to leaves changing colors. What is the dependent variable presented in these graphs? a) the seasons in which the measurements were taken b) the difference in pigment between spring and fall c) the measure of the amount of each pigment molecule present in leaves d) time at which the amount of pigment was measured e) the wavelengths of light reflected by each photosynthetic pigment

The light reactions of photosynthesis supply the Calvin cycle with: a) light energy. b) CO2 and ATP. c) ATP and NADPH & H+. d) sugar and O2. e) free electrons.

The movement of H+ into the stomach represented above is accomplished through: a) simple diffusion. b) facilitated diffusion. c) active transport. d) endocytosis. e) osmosis.

The movement of H+ into the stomach represented in this figure is accomplished through: A) facilitated diffusion. B) simple diffusion. C) active transport. D) endocytosis. E) osmosis.

The pH of a fluid is a measure of: A) its capacity to function as a soap. B) the concentration of phosphate groups. C) how acidic or basic it is. D) its enzymatic stability. E) the amount of adenosine triphosphate (ATP) in it.

The rough endoplasmic reticulum (ER) is the site of protein synthesis and the smooth ER is the site of lipid synthesis. What is the third compartment of the endomembrane system, and what is that compartment's function? a) lysosomes: sacs that export the proteins and lipids out of the cell b) vesicles: packages of proteins surrounded by cell membranes that sort the proteins and lipids for packaging c) Golgi apparatus: finishes the processing of the proteins and sorts them for export out of the cell d) ribosomes: the place of protein transcription e) None of the above is correct.

The secondary structure of a protein refers to: A) the linear assembly of amino acids into a chain. B) the way two or more polypeptides bind to each other. C) the twisting of the amino acid chain into a corkscrew-like shape or into a zigzag folding pattern. D) the configuration of the folded protein when bound to other proteins. E) None of the above is correct.

The set of analytical and mathematical tools designed to help researchers gain understanding from the data they gather is called: a) geometry. b) biology. c) statistics. d) genetics. e) experimentation.

The silk of a spider's web is remarkably strong, and its tensile strength is comparable to that of steel. Spider silk is a: a) lipid. b) non-carbon-containing molecule. c) protein. d) carbohydrate. e) nucleic acid.

To synthesize one glyceraldehyde 3-phosphate (G3P) molecule, the Calvin cycle has to fix three atoms of carbon from carbon dioxide to an organic molecule within the chloroplast. This process consumes how many molecules of ATP and NADPH, respectively, which were generated in the "photo" reactions? a) 3, 6 b) 6, 8 c) 9, 6 d) 9, 9 e) 9, 12

What can happen if an enzyme is altered, even slightly? a) It will continue to catalyze reactions, but at a slower rate. b) It will still catalyze reactions, but only at a higher temperature. c) Its active site may change, causing the enzyme to stop functioning. d) The amount of activator required to "turn on" the enzyme will need to increase. e) It will catalyze reactions too quickly, potentially causing illness for the individual.

What is the only cell type in animals that has a flagellum? a) the ovum b) the hair follicle c) the sperm cell d) kidney cells e) liver cells

When a chewing gum manufacturer makes the claim, "Four out of five dentists surveyed recommend sugarless gum for their patients who chew gum," how many dentists need to have been surveyed for the statement to be factually accurate? a) at least 500 b) at least 100 c) five d) four e) ten

Where are cell membrane components synthesized? a) lysosomes b) vesicles c) endoplasmic reticulum d) nucleus e) Golgi apparatus

Which cellular structure makes it possible for a cell to differ structurally and biochemically from its surroundings? A) endoplasmic reticulum B) nucleus C) plasma membrane D) nucleolus E) cell wall

Which of the following cellular components contains hydrolytic enzymes associated with the digestion of macromolecules? a) peroxisomes b) ribosomes c) lysosomes d) centrioles e) None of the above is correct.

Which of the following is NOT a form of kinetic energy? a) a chameleon tongue catching a bug b) a pitcher throwing a baseball c) a covalent bond linking phosphate molecules d) a ball rolling down a hill e) flowing water turning a turbine

Which of the following is NOT a function of the plant vacuole? A) predator deterrence B) nutrient storage C) photosynthesis D) physical support E) waste management

Which of the following is a polysaccharide? A) glucose, the chief cellular energy source B) insulin, the chief blood sugar regulator C) cellulose, the primary component of plant cell walls D) fructose, one of the most important blood sugars E) All of the above are polysaccharides.

Which of the following is an important feature of the scientific method? a) A good hypothesis does not necessarily need to be tested. b) If research results are not conclusive, the opinion of experts should be relied upon. c) Anyone should be able to repeat an experiment. d) A researcher's methods should not be described once desired results have been obtained. e) Once demonstrated, conclusions cannot be changed.

. Biological literacy is the ability to: a) use the process of scientific inquiry to think creatively about real-world issues that have a biological component. b) communicate ideas about biology to others. c) integrate ideas about biology into your decision-making. d) All of the above are components of biological literacy. e) Only b and c are components of biological literacy.

A chemical compound that releases OH− into a solution is called: a) a hydroxide ion. b) a solvent. c) a salt. d) a base. e) an acid.

A complex polymer built of amino acids is called a(n): A) monosaccharide. B) polysaccharide. C) amine. D) polypeptide. E) fatty acid.

A nucleotide consists of a phosphate group, a pentose sugar, and a __________________, all linked together by covalent bonds. a) potassium-containing base b) polypeptide c) phosphorus-containing base d) nitrogen-containing base e) triglyceride

A scientific theory is one that: a) perfectly sums up many years of accumulated experimental results. b) is based on hunches with no actual supporting evidence. c) changes each time a different observation is made. d) is the foundation of all scientific experiments. e) sounds the most plausible.

A unique characteristic of mitochondria is that they are inherited from the female parent only. Select the correct explanation for this phenomenon from the choices below. a) Mitochondria are only found in the female's egg cells and do not occur in male sperm cells. b) Mitochondria are found in both the female's egg cells and the male sperm cells, but the sperm exhaust their mitochondria during their swim up the female's fallopian tubes and are not viable upon fertilization. c) Mitochondria are found in both female egg cells and the male sperm cells, but after fertilization the female mitochondria outcompete the male mitochondria, which then die off. d) Male sperm cells have mitochondria, but because the sperm contributes DNA but no cytoplasm, no mitochondria are passed to the egg at fertilization. e) Mitochondria are found in both female egg cells and the male sperm cells, but the mitochondria from the male sperm cells cannot replicate during the early mitotic divisions in the embryo.

All of the following are proteins except: A) an enzyme. B) hemoglobin. C) insulin. D) cholesterol. E) an antibody.

An atom can be changed into an ion by adding or removing: A) a neutron. B) a proton. C) an orbital shell. D) an electron. E) an isotope.

An atom of iron has the atomic number 26. This means that it has: a) 52 protons. b) 13 neutrons. c) an atomic mass of 26. d) 26 protons. e) 13 electrons.

An element: A) is an atom that has lost either a proton or an electron. B) is a component of an atom. C) must occur naturally on earth somewhere. D) is a substance that cannot be broken down chemically into any other substance. E) All of the above are true.

Carbon-14 has the same: a) atomic number and atomic mass as carbon-12. b) atomic number and, therefore, the same number of neutrons as carbon-13. c) atomic mass as both carbon-12 and carbon-13. d) number of protons but more neutrons than carbon-12. e) atomic mass and, therefore, the same number of neutrons as carbon-12.

Cellular "fingerprints": A) are exposed on the cytoplasmic side of the membrane. B) are made of cholesterol. C) are 'erased' by the HIV virus. D) can help the immune system distinguish "self" from "non-self."

Certain molecules act like bank accounts for H+ ions because they can absorb excess H+ ions to keep a solution from becoming too acidic and release H+ ions to keep the solution from becoming too basic. Such molecules are called: a) enzymes. b) oxidating agents. c) reducing agents. d) buffers. e) catalysts.

Certain molecules act like bank accounts for H+ ions because they can absorb excess H+ ions to keep a solution from becoming too acidic and release H+ ions to keep the solution from becoming too basic. Such molecules are called: A) catalysts. B) enzymes. C) reducing agents. D) buffers. E) oxidating agents.

How are lysosomes distributed between different types of eukaryotic cells? a) Every different cell type has the same uniform number of lysosomes. b) The functions of lysosomes do not vary depending on cell type. c) Cells, such as white blood cells, do not need lysosomes, because they engulf bacteria on their own. d) Cells that process a lot of larger nutrients, such as liver cells, have larger amounts of lysosomes than other cells. e) Both a and b are correct.

How many hydrogen bonds are explicitly represented in this graphic? a) 1 b) 8 c) 0 d) 4 e) 10

If a researcher uses the same experimental setup as another study to collect data, but uses different research subjects, it is considered: a) exploration. b) a two-tailed test of the hypothesis. c) inductive reasoning. d) replication. e) extrapolation.

If the solution surrounding a cell contains less solute than the cytoplasm, the osmotic condition is said to be: A) isobaric. B) adiabatic. C) hypertonic. D) hypotonic. E) isotonic.

If you conduct an experiment that rejects your hypothesis, then: a) your experiment was poorly designed. b) your experiment was a failure. c) you should publish your results anyway. d) the null hypothesis was a better fit to your data. e) you should become an English major.

In a series of studies, researchers found a statistically significant positive correlation between the number of firefighters present at a fire and the amount of damage that the fire does. Which of the following is the BEST conclusion to be drawn from these studies? a) Firefighters make fires worse. b) Firefighters are effective in fighting fires. c) Causation is not correlation. d) Statistical data must be put in its proper context to be understood. e) To more accurately estimate the effect of the number of firefighters on the amount of damage, we would need to compare the amount of damage from fires of different sizes that are fought by similar numbers of firefighters.

In which organelle are lipids synthesized and modified within the eukaryotic cell? a) the Golgi apparatus b) the vesicle c) the rough endoplasmic reticulum d) the smooth endoplasmic reticulum e) the lysosome

A null hypothesis:

is the premise that no difference exists between a treatment and control group.

In your body, when energy is released from the breakdown of a molecule such as glucose: a) adenosine monophosphate is created. b) molecules of ATP are required to capture the heat generated by the reaction. c) all of the energy is lost as heat. d) some of the energy may be harnessed by building the unstable high-energy bonds that attach phosphate groups to ADP. e) adenosine diphosphate is created.

Interacting systems of molecules enclosed in compartments called __________ evolved 3.8 billion years ago in living organisms. A) brains B) mitochondria C) circulatory systems D) cells E) organs

Lactose is a combination of: a) glucose and ribose. b) glucose and fructose. c) glucose and maltose. d) glucose and galactose. e) sucrose and fructose.

Membrane-bound vesicles containing a substance synthesized by a cell fuse to the outer cell membrane and release their contents to the outside world. What is this process called? a) endocytosis b) excretocytosis c) phagocytosis d) exocytosis e) pinocytosis

Mitochondria are thought to have evolved from free-living bacteria that were incorporated into eukaryotic cells by endosymbiosis. Which of the following pieces of evidence for this hypothesis is INCORRECT? a) Mitochondria are enclosed by two membranes instead of a single membrane. b) Mitochondrial DNA is packaged as a single circular chromosome, similar to that of a bacterium. c) New mitochondria are formed by binary fission instead of being replicated during the cell cycle. d) Mitochondria can survive and reproduce independently when removed from the host cell. e) The phospholipid composition of the inner mitochondrial membrane is similar to that of the bacterial cell membrane.

Multiple atoms linked together are called: a) a reactant. b) an isotope. c) a substrate. d) a molecule. e) an element.

Oxygen gas produced during photosynthesis originates as: a) oxygen atoms contained in carbon dioxide are released when the carbon is fixed. b) oxygen atoms are released by the metabolism of carbohydrates. c) a molecule of chlorophyll oxidized by a photon. d) oxygen atoms contained in water molecules. e) a byproduct of nitrogen-fixing bacteria.

Plants have cell walls to give them more structural strength. In order to facilitate movement of molecules from one plant cell to another, there are channels called ___________________ that run through the cell walls. A) vacuoles B) desmosomes C) transport vesicles D) plasmodesmata E) plasma membranes

Pure water and aqueous solutions that are neither acidic nor basic are said to be: a) transparent. b) buffers. c) translucent. d) neutral. e) alkaline.

Sucrose (table sugar) and lactose (the sugar found in milk) are examples of: A) simple sugars. B) monosaccharides. C) polyunsaccharide sugars. D) disaccharides. E) naturally occurring enzymes.

Sugar and CO2 are dissolved in water to make carbonated soft drinks. Which of the following is the solute? a) the sugar only b) the CO2 only c) the water and the sugar d) the sugar and the CO2 e) the water and the CO2

The cell connections represented in the figure are: A) gap junctions. B) tight junctions. C) plasmodesmata. D) desmosomes. E) lysosomes.

The four most abundant elements in living organisms are: a) carbon, nitrogen, oxygen, and calcium. b) carbon, nitrogen, potassium, and oxygen. c) sodium, nitrogen, carbon, and silicon. d) hydrogen, nitrogen, oxygen, and carbon. e) carbon, hydrogen, nitrogen, and phosphorus.

The lysosomes in a human cell contain approximately ________ types of digestive enzymes. a) 1 b) 4 c) 10 d) 50 e) 500

The nucleus of an atom is usually made up of: A) neutrinos, which have no electrical charge. B) protons, which have a positive electrical charge, and proteins, which hold them together. C) neutrons, which have no electrical charge. D) protons, which have a positive charge, and neutrons, which have no electrical charge. E) protons, neutrons, and proteins that hold them together.

The outputs of cellular respiration are: a) oxygen, water, and ATP. b) oxygen, carbon dioxide, and ATP. c) carbon dioxide, water, and oxygen. d) carbon dioxide, water, and ATP. e) oxygen and sugar.

The principal components of cell membranes are: a) carbohydrates. b) proteins. c) nucleic acids. d) lipids. e) glycoproteins.

The secondary structure of a protein refers to the: a) three-dimensional folded structure of the protein. b) configuration of the folded protein when bound to other proteins. c) linear assembly of amino acids into a chain. d) twisting of the amino acid chain into a corkscrew-like shape or into a zigzag folding pattern. e) None of the above is correct.

The ultimate result of glycolysis is two molecules of: a) ethanol. b) NAD+. c) glucose. d) pyruvate. e) lactic acid.

There are three principal types of bonds that hold multiple atoms together. These are: A) covalent bonds, ionic bonds, and disulfide bonds. B) ionic bonds, hydrogen bonds, and ester bonds. C) hydrogen bonds, ionic bonds, and glycosidic linkages. D) covalent bonds, ionic bonds, and hydrogen bonds. E) phosphate bonds, disulfide bonds, and hydrogen bonds.

This organelle is found in: a) plants only. b) animals only. c) bacteria only. d) plants and animals. e) plants, animals, and bacteria.

To absorb large particles, cells engulf them within their plasma membrane in a process called: a) transcription. b) translation. c) replication. d) endocytosis. e) exocytosis.

Urine, with a pH of 6, is _________ times more acidic than seawater, with a pH of 8. a) 1000 b) 10 c) 6 d) 100 e) 8

Using the graphic above as a guide, what is Step 4 in the scientific process? a) Make observations. b) Formulate a hypothesis. c) Devise a testable prediction. d) Conduct a critical experiment. e) Draw conclusions and make revisions.

Water molecules form which type of bond with other water molecules? a) covalent bonds b) van der Waals bonds c) disulfide bridges d) hydrogen bonds e) ionic bonds

What are the two distinct "faces" of the phospholipids that make up the surface membrane of a cell? a) a hydrophilic head and a hydrophobic tail b) a hydrophobic head and a hydrophilic tail c) a phosphate group head and two fatty acid tails d) Both a and c are correct. e) Both b and c are correct.

What cell type in animals has a flagellum? A) the hair follicle B) kidney cells C) the ovum D) the sperm cell E) liver cells

What is Step 4 in the scientific process? A) Devise a testable prediction. B) Make observations. C) Draw conclusions and make revisions. D) Conduct a critical experiment. E) Formulate a hypothesis.

What is the main function of the nucleolus? a) It produces enzymes that are then exported to the lysosomes. b) It produces cell adhesion proteins that are then exported to the cell membrane. c) It is the site of photosynthesis in photosynthetic cells. d) It is the site of ribosome-subunit synthesis. e) Its function is not yet known.

When a photon strikes a molecule, the photon may do any of the following EXCEPT: a) bounce off the molecule. b) pass through the molecule. c) be absorbed by the molecule. d) be oxidized by an electron from the valence shell of the molecule. e) All of the above are possible outcomes of a photon striking a molecule.

When comparing two groups, the ______________, the more confident we are of the conclusion that a significant difference exists in the groups. a) larger the variation in each group b) smaller the difference between the two groups c) fewer the number of individuals in each group d) smaller the variation in each group e) more variables we measure

Which of the following does NOT occur during the Calvin cycle? a) carbon fixation b) oxidation of NADPH c) consumption of carbon dioxide d) splitting of water e) consumption of ATP

Which of the following is NOT a product of photosynthesis? a) water b) oxygen c) sugars d) carbon dioxide e) None of the above; all are products of photosynthesis.

Which of the following is TRUE regarding the metabolic machinery of humans and animals? a) All food first must be converted into glucose before it is usable. b) All food first must be converted into a carbon compound and an amino group before it is usable. c) All food first must be converted into glycerol and glucose before it is usable. d) Humans and animals can extract energy from sugars, lipids, and proteins. e) Simple sugars are the only real valuable energy source for humans and animals.

Which of the following is a correct description of how exocytosis functions in transporting molecules across the cellular membrane? A) A receptor protein on the outside of the cell binds a particular biochemical, causing the membrane to form an indetation and bring the biochemical into the cell. B) Nutrients are moved within the cell from one tightly woven network to another. C) Protein molecules on the interior of the cellular membrane trap molecules attached on the exterior side and bring them into the cell. D) Vesicles are filled with molecules in the interior of the cell and then fuse with the membrane to deposit the molecules outside of the cell. E) None of the above is correct.

Which of the following is the most important factor governing a cell's particular type of interaction with other cells? A) The location of the cell within an organism B) Whether or not the cell is an animal cell or a plant cell C) The type of animal the cell came from D) The pattern of proteins on the cell's surface E) Whether or not the cell is eukaryotic or prokaryotic

Which of the following is the primary site of protein assembly within eukaryotic cells? a) the vesicles b) the Golgi apparatus c) the smooth endoplasmic reticulum d) the ribosomes e) the peroxisome

Which of the following nucleotide bases are present in equal amounts in DNA? a) adenine and guanine b) adenine and cytosine c) thymine and cytosine d) adenine and thymine e) thymine and guanine

Which of the following statements about fermentation is TRUE? a) Fermentation produces energy more efficiently than aerobic respiration. b) Fermentation is an aerobic process. c) In fermentation, the molecules that are used as electron acceptors are the same as those used when glycolysis occurs in the presence of oxygen. d) Fermentation uses electrons generated from glycolysis and the Krebs cycle. e) In every case, the end product of fermentation is ethanol.

Which of the following statements about the light reactions of photosynthesis are correct? a) The energy of the sun is captured as potential energy. b) Pigments absorb light energy, which excites electrons. c) Water molecules split, providing a source of electrons. d) All of the above are correct. e) Only a and c are correct.

Which of the following statements is FALSE? a) Biofuels are produced from plant and animal products. b) Fats and oils share a chemical structure similar to gasoline. c) Life depends on energy gained from sunlight. d) Burning fossil fuels releases energy, oxygen, and water. e) Fossil fuels are the decayed remains of animals and plants.

Which of the following structures is NOT present in the cell membrane? a) a double layer of phospholipids b) transport proteins that form channels through the phospholipid bilayer c) peripheral proteins on the inner and outer surface d) a rigid matrix of actin and tubulin fibers e) carbohydrates attached to peripheral proteins

Which one of the following statements best represents the relationship between respiration and photosynthesis? a) Respiration occurs only in animals and photosynthesis occurs only in plants. b) Photosynthesis reverses the biochemical pathways of respiration. c) Respiration stores energy in complex organic molecules, while photosynthesis releases it. d) Photosynthesis stores energy in complex organic molecules, while respiration releases it. e) Photosynthesis occurs only in the day and respiration occurs only at night.

__________ is the smallest chemical unit of a type of pure substance. a) A cell b) A molecule c) An amino acid d) An atom e) A proton

Drug companies sometimes hire independent research laboratories to evaluate whether a drug they've discovered is effective or not in treating an illness. Companies MOST LIKELY do this to:

demonstrate that the scientists conducting the trial are not biased in concluding that the drug is effective.

The cell connections represented in the figure are:

desmosomes

The lysosome:

digests and recycles cellular waste products and consumed materials.

The nucleus:

directs cellular activity and stores hereditary information.

. In a well-designed experiment, the: a) prediction will be highly probable if the explanation is correct. b) prediction will be highly improbable if the explanation is incorrect. c) prediction will most likely be true. d) null hypothesis will not be tested. e) Both a and b.

A buffer is a chemical that: a) can quickly absorb excess H+ ions to keep a solution from becoming too acidic. b) can quickly release H+ ions to counteract any increases in the OH− concentration in a solution. c) is identical to baking soda. d) restores the pH of a solution to 7.0. e) Both a and b are correct.

A chemical compound that releases OH- into a solution is called: A) a hydroxide ion. B) a salt. C) a solvent. D) an acid. E) a base.

A cyclist rides her bike up a very steep hill. Which of the following choices properly describes this example in energetic terms? a) Potential energy in food is converted to kinetic energy as muscles push the cyclist up the hill. b) Kinetic energy is highest when the cyclist is at the crest of the hill. c) The cyclist produces the most potential energy as she cruises down the hill's steep slope. d) Gravity provides a source of potential energy. e) Both a and d are correct.

All macromolecules important in living systems contain: a) potassium. b) nitrogen. c) polymers. d) aldehydes. e) carbon.

All matter on earth, both living and non-living, is made up of: a) cells. b) DNA. c) carbohydrates. d) phospholipids. e) atoms.

All of the following are components of a single amino acid EXCEPT a(n): a) carboxyl group. b) nitrogen-containing amino group. c) variable side chain. d) alpha carbon. e) All of the above are components of a single amino acid.

All of the following are elements of biological literacy EXCEPT the ability to: a) use the process of scientific inquiry to think creatively about real-world issues having a biological component. b) communicate with others about issues having a biological component. c) integrate thoughts about issues having a biological component into your decision-making. d) write clearly and precisely about your observations, data gathering, and conclusions. e) All of the above are elements of biological literacy.

All of the following are elements of biological literacy EXCEPT: A) the ability to use the process of scientific inquiry to think creatively about real-world issues having a biological component. B) the ability to write clearly and precisely about your observations, data gathering, and conclusions. C) the ability to integrate thoughts about issues having a biological component into your decision-making. D) the ability to communicate with others about issues having a biological component. E) All of the above are elements of biological literacy.

All of the following are proteins EXCEPT: a) hemoglobin. b) an enzyme. c) an antibody. d) insulin. e) cholesterol.

Alon claimed that a tincture of a local herb was effective in lowering anxiety and was planning to invest in the product. As evidence of his claim, Alon, who had anxiety over his financial situation, said that he felt much better after the treatment, was much more relaxed, and no longer worried about his finances. Which of the following combinations of methodological flaws BEST characterizes Alon's investigation? a) lack of an appropriate outcome measure b) lack of appropriate controls and lack of an appropriate outcome measure c) lack of randomization, lack of replication, and lack of an appropriate outcome measure d) lack of replication and lack of appropriate controls e) lack of an appropriate outcome measure, replication, randomization, and controls

An atom of iron has the atomic number 26. This means that: A) it has an atomic mass of 26. B) it has 52 protons. C) it has 13 neutrons. D) it has 13 electrons. E) it has 26 protons.

Carbohydrates: a) in the form of oligosaccharides are often covalently bonded to proteins and lipids on the outer cell surface, where they serve as cell recognition signals. b) are a good source of sustained energy when they come in the form of polysaccharides. c) serve as carbon skeletons that can be rearranged to form other molecules that are essential for biological structures and functions like nucleic acids. d) act as a relatively fast available source of fuel. e) All of the above are correct.

Cyanide is such a deadly poison because it: a) blocks the passage of electrons to oxygen in the electron transport chain. b) effectively halts the production of ATP within mitochondria. c) breaks down the mitochondrial matrix. d) facilitates rapid transfer of electrons to carrier molecules. e) Both a and b are correct.

DNA is made of: a) fatty acids. b) amino acids. c) glucose molecules. d) four interconnected carbon rings. e) nucleotides.

Different steps in cellular respiration occur in different locations in the mitochondria. Which of the following does not properly match a step of respiration to its proper location? a) molecule of CO2 released: matrix b) two carbons manipulated through Krebs cycle: matrix c) energy transferred from NADH and FADH2 to ATP: inner mitochondrial membrane d) a gradient of hydrogen ions phosphorylates ATP: inner mitochondrial membrane e) All of the above are correct matches between function and location.

During photosynthesis, visible light has enough energy to: a) convert ADP into ATP. b) synthesize NADPH. c) split a water molecule into hydrogen and oxygen. d) reflect light in the red spectrum. e) excite electrons.

Each ATP molecule is composed of three separate subunits. Which of the following is NOT a proper description of one of these subunits? a) a five-carbon sugar b) a ribose c) three carbon-nitrogen rings d) an adenine e) a triphosphate group

Energy derived from cellular respiration can originate from: a) carbohydrates only. b) fats only. c) proteins only. d) carbohydrates and proteins only. e) carbohydrates, proteins, and fats.

Enzymes are composed of: A) sucrose molecules. B) glucose and sucrose molecules. C) nucleotides. D) glucose molecules. E) amino acids.

Glycolysis: a) is not performed in plants, which get their energy solely through photosynthesis. b) completely oxidizes glucose to carbon dioxide. c) is performed solely on the glucose ingested by the organism. d) is also referred to as the Krebs cycle. e) occurs in all cells.

If the concentrations of a particular molecule are equal on both sides of the membrane, facilitated diffusion will: a) ensure that the molecule becomes concentrated inside the cell. b) ensure that the molecule becomes concentrated outside the cell. c) ensure that the molecule stays impermeable to the membrane. d) ensure that the concentrations inside and outside the cell are both increased. e) be ineffective.

If your hypothesis is rejected, then: a) your experiment was a success. b) your experiment was poorly designed. c) your experiment was a failure. d) you should change the level of statistical significance until your hypothesis is accepted. e) you may still have learned something important about the system you were testing.

In cellular respiration, energy-rich: a) carbohydrate molecules are oxidized to carbon dioxide and water. b) fat molecules are oxidized to carbon dioxide and water. c) sugar molecules are oxidized to carbon dioxide and water. d) carbohydrate molecules are oxidized to carbon dioxide and oxygen. e) Only the first three choices are correct.

Life gains most of its energy from: a) carbohydrate molecules. b) sugar molecules. c) oxygen. d) water. e) sunlight.

Mammalian cells take in many molecules including hormones, antibodies, and blood proteins. This process is coordinated by proteins that recognize their specific target molecule. This process is best described as: a) phagocytosis. b) pinocytosis. c) exocytosis. d) active transport. e) receptor-mediated endocytosis.

N 14.01 What is missing from this cell of the periodic table? a) the atomic number for nitrogen, 6 b) the atomic number for nitrogen, 14 c) the atomic number for nitrogen, 28 d) the atomic number for nitrogen, 8 e) the atomic number for nitrogen, 7

Nuclear ______ are specialized holes in the ________- layered nuclear envelope that separates the nucleus from the ___________. A) passageways; one; cytoplasm B) vesicles; three; endoplasmic reticulum C) pores; one; endoplasmic reticulum D) vesicles; two; cytoplasm E) pores; two; cytoplasm

Of all the elements that occur on earth, how many are found in your body? a) 116 b) 4 c) 90 d) 10 e) 25

One of the four nucleotide bases in DNA is replaced by a different base in RNA. Which base is it, and what is it replaced by? A) guanine, replaced by cytosine B) cytosine, replaced by guanine C) thymine, replaced by guanine D) adenine, replaced by uracil E) thymine, replaced by uracil

Organic molecules consisting of only hydrogen and carbon are called: a) carbohydrates. b) hydroxyls. c) enantiomers. d) fats. e) hydrocarbons.

Phospholipids assemble spontaneously into bilayers driven by the attraction of their "tail" portions to each other and of their "head" portions to each other. The tail regions are: A) adhesive. B) hydrophilic. C) molecularly charged. D) cohesive. E) hydrophobic.

Saturated fatty acids have _________________ than unsaturated fatty acids, which is why they exist as a ____________ at room temperature. a) fewer hydrogen atoms; solid b) more double bonds; liquid c) more carbon atoms; solid d) more glycerol molecules; liquid e) fewer double bonds; solid

Some have claimed that the herb echinacea reduces the likelihood of catching the common cold. In many hundreds of studies, this claim has been refuted. Assuming these studies were properly conducted, which of the following is a scientifically responsible claim that an echinacea advocate could make in support of further research on this subject. a) The effective dosage of echinacea was outside the range of the dosages given in the scientific studies. b) The investigators were paid off by the drug companies. c) The effective length of time needed for taking echinacea is longer than that provided in any of the scientific studies. d) All of the above are scientifically responsible claims that an echinacea advocate could make in support of further research on this subject. e) Only a and c are scientifically responsible claims that an echinacea advocate could make in support of further research on this subject.

The Russian-American biochemist Phoebus Levene was the first to determine that nucleotides may contain one of four different nitrogen-containing bases. Levene believed that the nitrogen-containing bases occurred in equal amounts in DNA. What is the actual proportion of these bases? a) DNA contains twice as much of adenine and thymine as guanine and cytosine. b) All four do actually occur in equal amounts. Levene was right. c) DNA contains equal amounts of guanine and thymine, and equal amounts of adenine and cytosine. d) DNA contains equal amounts of adenine and guanine, and equal amounts of thymine and cytosine. e) DNA contains equal amounts of adenine and thymine, and equal amounts of guanine and cytosine.

The electron transport chain in eukaryotic mitochondria results in all of the following EXCEPT: a) a proton concentration gradient across the inner mitochondrial membrane. b) the conversion of NADH to NAD+ (as it gives up electrons). c) the conversion of molecular oxygen to water. d) the production of ATP via ATP synthase. e) the breakdown of glycogen to glucose.

The figure represents which class of chemical compounds? A) Fats B) acids C) carbohydrates D) proteins E) sterols

The generation of ATP by the movement of protons down their concentration gradient occurs in: a) mitochondria. b) chloroplasts. c) endoplasmic reticula. d) All of the above are correct. e) Only a and b are correct.

The lipids within the fluid mosaic of the plasma membranes are held in place by: a) covalent bonds. b) hydrogen bonds. c) ionic bonds. d) disulfide bridges. e) hydrophobic interactions.

The most effective portion(s) of the visible spectrum in driving photosynthesis is(are): a) the violet-blue portion. b) the yellow-green portion. c) the red-orange portion. d) Both a and b are correct. e) Both a and c are correct.

The number of protons in an element, also called its ____________, identifies the element. A) ion B) charge C) nucleus D) atomic weight E) atomic number

The pH of a fluid is a measure of: a) its capacity to function as soap. b) its enzymatic stability. c) the concentration of phosphate groups. d) the amount of adenosine triphosphate (a-pH) in it. e) how acidic or basic it is.

The passive transport of water across a membrane from a solution of lower solute concentration to a solution of higher solute concentration is best described as: A) facilitated diffusion. B) general diffusion. C) active transport. D) passive transport. E) osmosis.

The phosphate groups in ATP: a) represent a significant source of stored energy. b) release energy when separated from the rest of the molecule. c) are covalently bonded to each other. d) are negatively charged. e) All of the above are correct.

The scientific method will never prove or disprove: a) the existence of God. b) the beauty of Shakespeare's sonnets. c) the ability of echinacea to prevent the common cold. d) All of the above are examples of statements that the scientific method will never prove or disprove. e) Only a and b are examples of statements that the scientific method will never prove or disprove.

The tendency of molecules to stick together, called cohesion, is stronger in water than other liquids because the polarity of water allows a(n): a) hydrogen atom from one water molecule to form an ionic bond with the oxygen atom of another water molecule. b) hydrogen atom from one water molecule to form a hydrogen bond with the hydrogen atom of another water molecule. c) hydrogen atom from one water molecule to form a covalent bond with the oxygen atom of another water molecule. d) oxygen atom from one water molecule to form a hydrogen bond with the oxygen atom of another water molecule. e) hydrogen atom from one water molecule to form a hydrogen bond with the oxygen atom of another water molecule.

Three principal types of bonds hold multiple atoms together. These are: a) phosphate bonds, disulfide bonds, and hydrogen bonds. b) hydrogen bonds, ionic bonds, and glycosidic linkages. c) covalent bonds, ionic bonds, and disulfide bonds. d) ionic bonds, hydrogen bonds, and ester bonds. e) covalent bonds, ionic bonds, and hydrogen bonds.

When you put a piece of chocolate on your tongue, your brain registers a sensation of sweetness. What aspect of molecules is responsible for their having a particular taste? a) the total number of electron shells in the atoms of the molecule b) the total number of protons in the molecule c) the ratio of covalent bonds to ionic bonds joining the atoms of the molecule d) the amount of hydrogen bonds in the molecule (more hydrogen bonds = sweeter taste) e) the molecule's shape

Which of the following CANNOT occur? a) two cousins having identical mitochondrial DNA b) you and your great-grandmother having identical mitochondrial DNA c) you and your full-sibling sister having identical mitochondrial DNA d) you and your full-sibling brother having different nuclear DNA e) None of the above; all of these are possible.

Which of the following areas is NOT heavily influenced by biology? a) agriculture b) environmental issues c) criminology d) behavioral issues e) Biology heavily influences ALL of these areas.

Which of the following elements have four electrons in their outer shells? a) oxygen and sulfur b) nitrogen and phosphorus c) boron and aluminum d) fluorine and chlorine e) carbon and silicon

Which of the following facts supports the claim that mitochondria developed from bacteria that were long ago phagocytosed into eukaryotic cells? a) Mitochondria have flagella for motion. b) Mitochondria have proteins for the synthesis of ATP. c) Mitochondria are the "powerhouses" of the cell. d) Mitochondria are small and easily transported across the membrane. e) Mitochondria have their own DNA.

Which of the following is NOT a way in which the cell's surface membrane interacts with the exterior environment? a) The cellular surface receives and transmits incoming messages. b) The cellular surface controls which substances enter and leave the cell. c) The cellular surface mediates attachments to other cells. d) The cellular surface mediates interactions with extracellular material. e) The cellular surface organizes the interior organelle organization of the cell.

Which of the following is NOT an example of a theory? a) Species evolve through natural selection. b) Molecules are composed of atoms. c) Organisms are composed of cells. d) Diseases are caused by germs. e) All of the above are considered to be theories.

Which of the following is NOT an important biological function of lipids? a) insulation b) energy storage c) protection of internal organs and tissues d) regulation of growth and development e) All of the above are important biological function of lipids.

Which of the following is NOT an important structural feature on the surface membrane of an animal cell? a) glycoproteins b) cholesterol c) carbohydrates d) lipid bilayer e) cell wall

Which of the following is a feature of mitochondria that aids in their unique ability to harness energy from food? a) "bag-within-a-bag" structure b) lack of an internal membrane c) inner "bag" structure studded with electron carrier molecules d) presence of a thylakoid membrane e) Both a and c are correct.

Which of the following is an important difference between the rough endoplasmic reticulum and the smooth endoplasmic reticulum? a) The rough endoplasmic reticulum is the site of much protein folding and packaging, whereas the smooth endoplasmic reticulum is the site of lipid synthesis. b) The smooth endoplasmic reticulum is the site of protein synthesis, folding, and packaging, whereas the rough endoplasmic reticulum is the site of lipid synthesis. c) The rough endoplasmic reticulum is covered in ribosomes, whereas the smooth endoplasmic reticulum is not. d) The rough endoplasmic reticulum is studded with chloroplasts, whereas the smooth endoplasmic reticulum is not. e) Both a and c are correct.

Which of the following is an important difference between the rough endoplasmic reticulum and the smooth endoplasmic reticulum? A) The rough endoplasmic reticulum is the site of much protein folding and packaging while the smooth endoplasmic reticulum is the site of lipid synthesis. B) The rough endoplasmic reticulum is studded with chloroplasts, while the smooth endoplasmic reticulum is not. C) The rough endoplasmic reticulum is covered in ribosomes while the smooth endoplasmic reticulum is not. D) The smooth endoplasmic reticulum is the site of protein synthesis, folding, and packaging while the rough endoplasmic reticulum is the site of lipid synthesis. E) Both a) and c) are correct.

Which of the following is found in both prokaryotic and eukaryotic cells? A) peroxisome B) Golgi apparatus C) centriole D) lysosome E) ribosome

Which of the following is not an important biological function of lipids? A) Insulation B) protection of internal organs and tissues C) regulation of growth and development D) energy storage E) All of the above are true.

Which of the following is the most important factor governing a cell's particular type of interaction with other cells? a) the location of the cell within an organism b) whether or not the cell is eukaryotic or prokaryotic c) whether or not the cell is an animal cell or a plant cell d) the type of animal the cell came from e) the pattern of glycoproteins and glycolipids on the cell's surface

Which of the following questions CANNOT be answered by the scientific method? a) Does taking echinacea reduce the intensity or duration of the common cold? b) Does chemical runoff give rise to hermaphrodite fish? c) Does hair that is shaved grow back coarser? d) Is eyewitness testimony in criminal proceedings reliable? e) Which Shakespearean sonnet is the most beautiful?

Which of the following statements about cellulose is FALSE? a) Although it is not digestible, cellulose is still important to humans' diets. b) The cellulose we eat passes right through our digestive system unused. c) Cellulose and starch are made from similar molecules. d) Cellulose has a slightly different three-dimensional structure from starch. e) All of the above statements about cellulose are TRUE.

Which of the following statements about the cytoskeleton is FALSE? a) It is responsible for some cellular movement. b) It is made from proteins that act as a scaffolding. c) It is present in both prokaryotic and eukaryotic cells. d) It is a three-dimensional structure that fills the cytoplasm. e) All of the above statements are true.

Which one of the following organelles is NOT found in both plant and animal cells? a) nucleus b) peroxisome c) mitochondrion d) smooth endoplasmic reticulum e) central vacuole

Which statement about phospholipids is FALSE? a) They are hydrophobic on one end. b) They are a major constituent of cell membranes. c) They are hydrophilic at one end. d) They contain glycerol linked to fatty acids. e) Because their phosphate groups repel each other, they are used as organisms' chief form of short-term energy.

__________ is the smallest chemical unit of a type of pure substance. A) A molecule B) A cell C) An amino acid D) A proton E) An atom

_________________ may have biases that affect their abilities to perform in an objective fashion. a) Scientists b) Research assistants c) Politicians d) Authors of test questions e) All of the above are correct.

In a well-designed experiment:

e) a) and b) are both correct.

To absorb large particles, cells engulf them within their plasma membrane in a process called:

endocytosis

Where are cell membrane components synthesized?

endoplasmic reticulum

Membrane-bound vesicles containing a substance synthesized by a cell fuse to the outer cell membrane and release their contents to the outside world. What is this process called?

exocytosis

Which of the following are all monosaccharides?

glucose and fructose

According to the clip, what is the main function of chloroplasts?

harvest light energy to make sugars and other plant tissue

The C4 mechanism of carbon fixation is an advantage for plants that live in:

hot, dry climates.

A weak attraction between a slightly positive region of one polar molecule and a slightly negative region of another polar molecule is called a(n):

hydrogen bond.

The four most abundant elements in living organisms are:

hydrogen, nitrogen, oxygen, and carbon.

In a phospholipid, the head is _____, and the fatty acid is _____.

hydrophilic, hydrophobic

An element:

is a substance that cannot be broken down chemically into any other substance.

The object pictured above:

is an animal cell.

Scientific theories do not represent speculations or guesses about the natural world. Rather they are hypotheses—proposed explanations for natural phenomena—that have been:

so strongly and persuasively supported by empirical observation that the scientific community views them as unlikely to be altered by new evidence.

Every time a source of energy is converted from one form to another:

some of the energy is converted to heat, which is one of the least usable forms of kinetic energy.

Carbon dioxide and oxygen move into and out of plants through:

stomata

The specialized cells that facilitate gas exchange in plants are known as:

stomata

Life gains most of its energy from:

sunlight.

A deer is grazing on some hillside shrubs. It bites into the leaves of one plant and immediately spits it out because it tastes bad. Which cellular component saved the plant from being eaten down to its roots by the deer?

the central vacuole, which stores nasty-tasting materials

In studying the way energy is handled in the universe, one scientist summarized: "Not only can't you get something for nothing, but you can't even break even!" Which of the following do these two statements best summarize?

the first and second laws of thermodynamics

In eukaryotes where can the organism's complete set of DNA be found?

the nucleus

Biology is ________.

the study of living things

A powerful way to demonstrate that observed differences between a treatment group and a control group truly reflect the effect of the treatment is for researchers:

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