Exam 1

Question 1

Dr. Foster is studying the effectiveness of a new memory-boosting diet supplement. He posts an ad for subjects at two local colleges. He assigns 55 students from college A to the treatment group (daily doses of the diet supplement) and 60 students from college B (no supplement) to the control group. After 6 months of the study, Dr. Foster gives all of the students in each group a memory test. The treatment group scores an average of 20 points higher than the control group (a significant difference). Based on these findings, Dr. Foster declares that the memory-boosting supplement helps increase a person’s memory. What would improve the design of the
Dr. Foster’s study?

a. Make the number of students in both groups the same

b. Randomly assign students to one of the two conditions (treatment or control).

c. Administer the supplement for a longer period of time.

d. Give the control group half the daily dosage of the diet supplement that the treatment group receives.

e. Deprive the control group of sleep to see if that also affects memory recall.

Answer 1

Randomly assign students to one of the two conditions (treatment or control).

Question 2

The tendency of molecules to stick together, called cohesion, is stronger in water than in 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.

Answer 2

hydrogen atom from one water molecule to form a hydrogen bond with the oxygen atom of another water molecule.

Question 3

Which issue would be least helped by application of the scientific method?

a. comparing the effectiveness of two potential antibiotics

b. determining the most effective safety products for automobiles

c. developing more effective high school curricula

d. formulating public policy on euthanasia

e. evaluating the relationship between violence in video games and criminal behavior in teens

Answer 3

formulating public policy on euthanasia

Question 4

Which of these is not a function of proteins?

a. They help fight infection.

b. They form structural features, such as hair and bone.

c. They transport molecules within cells and throughout the body.

d. They are a chief form of long-term energy storage.

e. They help catalyze chemical reactions.

Answer 4

They are a chief form of long-term energy storage.

Question 5

On food packages, “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. carbohydrate.

b. nucleic acid.

c. protein.

d. lipid.

e. amino acid.

Answer 5

carbohydrate.

Question 6

Based on their descriptions, which of these atoms is least likely to interact with other atoms to form molecules?

a. lithium (Li) - 1st shell: 2 electrons, 2nd shell: 1 electron

b. neon (Ne) - 1st shell: 2 electrons, 2nd shell: 8 electrons

c. nitrogen (N) - 1st shell: 2 electrons; 2nd shell: 5 electrons

d. carbon (C) - 1st shell: 2 electrons; 2nd shell: 4 electrons

e. hydrogen (H) - 1st shell: 1 electron

Answer 6

neon (Ne) - 1st shell: 2 electrons, 2nd shell: 8 electrons

Question 7

Which of these is not a factor that influences the reaction rate of enzymes?

a. temperature

b. pH

c. presence of inhibitors or activators

d. enzyme and substrate concentration

e. enzyme size

Answer 7

enzyme size

Question 8

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. buffers.

c. reducing agents.

d. isotopes

e. oxidizing agents.

Answer 8

buffers.

Question 9

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 hydrogen bonds.

d. covalent bonds, ionic bonds, and disulfide bonds.

e. ionic bonds, hydrogen bonds, and ester bonds.

Answer 9

covalent bonds, ionic bonds, and hydrogen bonds.

Question 10

Biological literacy includes the ability to

a. use scientific-sounding language to promote consumer products.

b. make assumptions about the world, based on the opinions of others.

c. determine if one phenomenon caused another, just by making one or a few observations.

d. apply the scientific method to evaluate non-quantifiable, subjective information.

e. use the process of scientific inquiry to think creatively about real-world issues that have a biological component.

Answer 10

use the process of scientific inquiry to think creatively about real-world issues that have a biological component.

Question 11

Which carbohydrate is of most importance to living organisms?

a. fructose

b. maltose

c. galactose

d. glucose

e. cellulose

Answer 11

glucose

Question 12

A useful scientific hypothesis is one that is:

a. proven.

b. testable.

c. conclusive.

d. accurate.

e. abstract.

Answer 12

testable.

Question 13

You conduct a study to determine how the amount of time spent studying affects students’ performance on exams, and you want to display the data you have collected using a line graph. What is the dependent variable, and on which axis should it be represented in your graph?

a. The dependent variable is “time spent studying,” and it should be represented on the x-axis.

b. The dependent variable is “time spent studying,” and it should be represented on the y-axis.

c. The dependent variable is “performance on exams,” and it should be represented on the x-axis.

d. The dependent variable is “performance on exams,” and it should be represented on the y-axis.

e. The dependent variable is “time spent studying,” and it can be represented on either the x- or y-axis

Answer 13

The dependent variable is “performance on exams,” and it should be represented on the y-axis.

Question 14

After one conducts a critical experiment, what is the next step in the scientific process?

a. Make observations.

b. Formulate a hypothesis.

c. Draw conclusions and make revisions.

d. Devise a testable prediction.

e. Formulate a null hypothesis.

Answer 14

Draw conclusions and make revisions.

Question 15

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

a. a neutron.

b. a proton.

c. an electron

d. either a neutron or a proton.

e. either a proton or an electron.

Answer 15

an electron

Question 16

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

a. The control group and the test groups may have several differences between them.

b. The control group is identical to each test group, except for the variable under investigation.

c. There can be more than one difference between the control group and test groups but not several differences; otherwise, 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.

Answer 16

The control group is identical to each test group, except for the variable under investigation.

Question 17

The four most abundant elements in living organisms are:

a. carbon, hydrogen, potassium, and oxygen.

b. hydrogen, nitrogen, carbon, and silicon.

c. carbon, nitrogen, hydrogen, and calcium.

d. hydrogen, nitrogen, oxygen, and carbon.

e. carbon, hydrogen, nitrogen, and phosphorus.

Answer 17

hydrogen, nitrogen, oxygen, and carbon.

Question 18

If your hypothesis is “Estrogens in sewage runoff can cause individual fish to develop both male and female reproductive structures,” what is your null hypothesis?

a. Estrogens in sewage runoff have no effect on the development of fish reproductive structures.

b. Estrogens in sewage runoff cause individual turtles to develop both male and female reproductive structures.

c. Estrogens in sewage runoff cause fish possessing both male and female reproductive structures into fish with either male or female reproductive structures.

d. Testosterones in sewage runoff cause individual fish to develop both male and female reproductive structures.

e. Testosterones in sewage runoff have no effect on the development of fish reproductive structures.

Answer 18

Estrogens in sewage runoff have no effect on the development of fish reproductive structures.

Question 19

One likely consequence of protein denaturation is that the:

a. protein becomes more tightly folded.

b. protein adds another polypeptide to its folded shape.

c. protein loses its functionality.

d. protein performs more efficiently than it did before.

e. protein’s primary structure changes.

Answer 19

protein loses its functionality.

Question 20

A substance similar to table salt, called magnesium chloride, separates into positively charged magnesium ions and negatively charged chloride ions when placed in water. If you were to look at the magnesium ions dissolved in the water, what would you see?

a. The magnesium ions would be surrounded by chloride ions.

b. The magnesium ions would be surrounded by water molecules with their hydrogen atoms facing the magnesium ions.

c. The magnesium ions would be surrounded by water molecules with their oxygen atoms facing the magnesium ions.

d. The magnesium ions would be drifting by themselves, without any water molecules nearby.

e. The magnesium ions would be covalently bonded to water molecules.

Answer 20

The magnesium ions would be surrounded by water molecules with their oxygen atoms facing the magnesium ions.

Question 21

Several amino acids joined together form a(n):

a. monosaccharide.

b. polypeptide.

c. fatty acid.

d. polysaccharide.

e. amine.

Answer 21

polypeptide.

Question 22

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. hydrophobic.

c. molecularly charged.

d. adhesive.

e. cohesive.

Answer 22

hydrophobic.

Question 23

Pairing rice and lentils together in a single meal is advisable because, together, they:

a. are more easily digested than if eaten separately.

b. provide all the nutrients and vitamins your body needs.

c. provide all the essential amino acids.

d. function in at least two ways, such as serving in structural or protective roles.

e. provide a meal that is rich in complete proteins.

Answer 23

provide all the essential amino acids.

Question 24

Identify the statement that correctly describes hydrogen bonds.

a. any bond with a hydrogen

b. the attraction between a slightly positive, covalently bonded hydrogen atom and a slightly negative atom of another molecule

c. a bond between two hydrogen atoms to form H2

d. attraction between hydrogen and oxygen to form a water molecule

e. attraction between oppositely charged ions

Answer 24

the attraction between a slightly positive, covalently bonded hydrogen atom and a slightly negative atom of another molecule

Question 25

While measuring the fingers of people in different groups to study physical symmetry, a researcher noted that when she measured individuals from a group that she predicted would be more symmetrical, she was more likely to remeasure if her digital ruler indicated a large asymmetry. This is an example of which of the following?

a. experimenter bias

b. placebo effect

c. double-blind experimental design

d. randomized effect

e. a treatment/control study

Answer 25

experimenter bias

Question 26

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 groups are filled randomly using no particular criteria.

e. the experimenter knows which subjects are in the experimental group but not the control group.

Answer 26

neither the experimenter nor the subject know whether the subject is in a control group or an experimental group.

Question 27

Glucose ingested in your diet enters the bloodstream at a concentration of about 0.1%. If there is more glucose circulating in your blood than is necessary to meet your current energy needs, which of these serves as easily accessible, temporary energy storage?

a. glucose converted to fat

b. complex carbohydrates in the muscles

c. glycogen stored in the liver and the muscles

d. disaccharides in the blood stream

e. water molecules bound to fat

Answer 27

glycogen stored in the liver and the muscles

Question 28

Carbon:

a. has no vacancies in its outermost shell.

b. can form up to 4 bonds with other atoms.

c. can’t form bonds with other atoms of carbon.

d. can hold 4 electrons in its first electron shell.

e. is the least reactive of all elements.

Answer 28

can form up to 4 bonds with other atoms.

Question 29

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

a. you didn’t follow the scientific method.

b. you need to redo your experiment until you get the expected result.

c. you should revise the hypothesis.

d. you should not report the experiment.

e. the experiment was a failure.

Answer 29

you should revise the hypothesis.

Question 30

Which of these is not a characteristic of saturated fats?

a. They are liquid at room temperature.

b. Every carbon atom is attached to the maximum number of hydrogen atoms.

c. Only single hydrocarbon bonds are present.

d. They pack tightly together.

e. They are found in meat and eggs.

Answer 30

They are liquid at room temperature.

Question 31

Which of the following is not a difference between DNA and RNA?

a. The building blocks of DNA are nucleotides, whereas the building blocks of RNA are amino acids.

b. The sugar deoxyribose is found in DNA, whereas the sugar ribose is found in RNA

c. DNA is double-stranded, whereas RNA is single-stranded.

d. Thymine is a base of DNA, whereas thymine is not found in RNA.

e. Uracil is a base of RNA, whereas uracil is not found in DNA.

Answer 31

The building blocks of DNA are nucleotides, whereas the building blocks of RNA are amino acids.

Question 32

Choose the best description of a covalent bond from the choices below.

a. Two water molecules interact due to partial charges on the oxygen and hydrogen atoms.

b. A magnesium donates electrons and forms bonds with two chloride ions.

c. A bond forms between a hydrogen from one molecule and a nitrogen from another molecule.

d. A nitrogen atom shares electrons with three hydrogen atoms.

e. A positive potassium ion forms a bond with a negative chloride ion.

Answer 32

A nitrogen atom shares electrons with three hydrogen atoms.

Question 33

The pH scale is a direct measure of the concentration of

a. hydrogen ions in a solution.

b. hydroxide ions in a solution.

c. hydrogen atoms in a solution.

d. salt in a solution.

e. buffers in a solution.

Answer 33

hydrogen ions in a solution.

Question 34

All lipids are:

a. triglycerides.

b. not soluble in water

c. polar.

d. hydrophilic.

e. polymers of fatty acids.

Answer 34

not soluble in water

Question 35

Why might we refer to a complex carbohydrate as a “time release” pellet of energy?

a. Simple sugars give a quick burst of energy, because the sugars are almost immediately available.

b. The molecular shape of a complex carbohydrate does not stimulate the sweetness receptors on the tongue.

c. Simple sugars become available gradually as the complex carbohydrates are broken down into their simple sugar components.

d. Energy from complex carbohydrates is usually converted into fat, a form of long-term energy storage.

e. Complex carbohydrates contain more fiber and can help maintain the feeling of being full.

Answer 35

Simple sugars become available gradually as the complex carbohydrates are broken down into their simple sugar components.

Question 36

A nucleotide consists of a phosphate group, a molecule of sugar, and a _____ all linked together by covalent bonds.

a. polypeptide

b. triglyceride

c. nitrogen-containing base

d. sugar-containing base

e. phosphorus-containing base

Answer 36

nitrogen-containing base

Question 37

In your lab, you notice that pea plants that were given a mixture of water and fertilizer have grown nearly three times as tall as pea plants that were given water only. This step of the scientific method is:

a. stating a law.

b. making an observation.

c. drawing a conclusion.

d. conducting a critical experiment.

e. formulating a theory.

Answer 37

making an observation.

Question 38

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. genetics.

d science

e. statistics

Answer 38

statistics

Question 39

The thing that distinguishes one element, such as chlorine, from another, such as neon, is the number of

a. protons in the nucleus.

b. protons and neutrons in the nucleus

c. electrons.

d. protons, neutrons, and electrons.

e. neutrons in the nucleus.

Answer 39

protons in the nucleus.

Question 40

Bleach has an approximate pH of 13, and pure water has a pH of 7. How much more basic is bleach than pure water?

a. 100x

b. 1,000x

c. 10,000x

d. 100,000x

e. 1,000,000x

Answer 40

1,000,000x