Question 1

Which of the following best distinguishes between a proximate and an ultimate explanation for why birds migrate south for the winter?

Accepted Answer

Proximate: Birds migrate because decreasing daylight triggers hormonal changes. Ultimate: Birds migrate because migration increases survival and reproductive success.

Question 2

A researcher wants to test the effect of a new fertilizer on plant growth. Which of the following is the best example of a controlled experimental design?

Accepted Answer

Planting seeds in identical pots, giving half the new fertilizer and half no fertilizer, keeping all other conditions the same.

Question 3

Which of the following is a testable hypothesis?

Accepted Answer

If fertilizer increases nitrogen availability, then plants given fertilizer will grow taller than those without fertilizer.

Question 4

Which of the following statements about atomic structure is correct?

Accepted Answer

Protons and neutrons are found in the nucleus, while electrons occupy orbitals around the nucleus.

Question 5

Given the electronegativity values: Oxygen = 3.5, Hydrogen = 2.1, Sodium = 0.9, Chlorine = 3.0. Which bond is most likely to be ionic?

Accepted Answer

Na-Cl

Question 6

Which property of water is most directly responsible for the cooling effect of sweating in humans?

Accepted Answer

High heat of vaporization

Question 7

If the pH of a solution changes from 6 to 4, what happens to the hydrogen ion concentration $$[H^+]$$?

Accepted Answer

$$[H^+]$$ increases by a factor of 100

Question 8

Which functional group acts as a base and can accept a proton ($$H^+$$)?

Accepted Answer

Amino group ($$-NH_2$)

Question 9

Which statement best describes the second law of thermodynamics as it applies to living systems?

Accepted Answer

Living systems increase the entropy of their surroundings while maintaining order internally.

Question 10

A reaction has $$\Delta G = -15 kJ/$$mol. Which of the following is true?

Accepted Answer

The reaction is exergonic and spontaneous.

Question 11

Which of the following best explains why enzymes do not make endergonic reactions exergonic?

Accepted Answer

Enzymes lower the activation energy but do not change the overall free energy change ($$\Delta G) of $$the reaction.

Question 12

Which bond is responsible for the primary structure of a protein?

Accepted Answer

Peptide bonds

Question 13

Which of the following best describes the structure of a nucleotide?

Accepted Answer

A phosphate group, a five-carbon sugar, and a nitrogenous base

Question 14

Which of the following is a function of rRNA in the cell?

Accepted Answer

Forming the core of the ribosome and catalyzing peptide bond formation

Question 15

Which of the following carbohydrates is a major structural component in plant cell walls?

Accepted Answer

Cellulose

Question 16

Why do cells not store energy by accumulating large amounts of glucose monomers?

Accepted Answer

High concentrations of glucose would cause water to enter the cell by osmosis, potentially causing cell lysis.

Question 17

Which of the following is a property of unsaturated fatty acids compared to saturated fatty acids?

Accepted Answer

They tend to be liquid at room temperature due to kinks in their hydrocarbon chains.

Question 18

Which of the following substances is most likely to diffuse directly through a pure phospholipid bilayer without the help of a protein?

Accepted Answer

Oxygen ($$O_2)$$

Question 19

A cell is placed in a solution with a higher concentration of solute than inside the cell. What will happen to the cell?

Accepted Answer

Water will move out of the cell by osmosis.

Question 20

Which of the following best describes the role of ATP in coupling reactions in cells?

Accepted Answer

ATP hydrolysis releases free energy ($$\Delta G \u003c 0) $$that can be used to drive endergonic reactions.

Principles of Biology: Unit 1 Study Guide – Biological Molecules, Chemistry, and Membranes

Study Guide - Practice Questions

Study Guide - Flashcards