Question 1

Which of the following best illustrates an ultimate explanation for why birds migrate seasonally?

Accepted Answer

Birds migrate because individuals that move to areas with more food during winter have higher reproductive success.

Question 2

A researcher wants to test whether a new fertilizer increases plant growth. Which of the following is the best example of a testable hypothesis for this experiment?

Accepted Answer

If plants are given the new fertilizer, then their average height after 4 weeks will be greater than plants not given the fertilizer.

Question 3

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 4

Given the electronegativity values: Oxygen = 3.5, Hydrogen = 2.1, and Sodium = 0.9, which bond is most likely to be ionic?

Accepted Answer

Sodium-Oxygen

Question 5

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

Accepted Answer

High heat of vaporization

Question 6

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 7

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

Accepted Answer

Amino group ($$-NH_2$)

Question 8

Which of the following statements about the second law of thermodynamics is correct?

Accepted Answer

Every energy transfer increases the entropy of the universe.

Question 9

A reaction has a change in Gibbs free energy $$\Delta G = -15 kJ/$$mol. Which of the following is true?

Accepted Answer

The reaction is exergonic and spontaneous.

Question 10

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

Accepted Answer

Enzymes lower the activation energy but do not affect the overall free energy change.

Question 11

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

Accepted Answer

Peptide bonds

Question 12

Which of the following best describes the difference between DNA and RNA?

Accepted Answer

DNA is usually double-stranded, while RNA is usually single-stranded.

Question 13

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

Accepted Answer

Cellulose

Question 14

Why do cells not store energy as 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 15

Which of the following best describes a saturated fatty acid?

Accepted Answer

It has no double bonds and is usually solid at room temperature.

Question 16

A cell membrane is composed primarily of which of the following?

Accepted Answer

Phospholipids and proteins

Question 17

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

Accepted Answer

Oxygen ($$O_2)$$

Question 18

Which of the following best describes active transport across a cell membrane?

Accepted Answer

Movement of molecules against their concentration gradient using energy, often from ATP

Question 19

A red blood cell is placed in a solution and swells until it bursts. What can you conclude about the solution?

Accepted Answer

The solution is hypotonic to the cell.

Question 20

Which of the following is an example of facilitated diffusion?

Accepted Answer

Glucose entering a cell via a specific membrane protein

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

Study Guide - Practice Questions

Study Guide - Flashcards