Question 1

Which of the following best explains why water is considered essential for life on Earth?

Accepted Answer

Water's ability to form hydrogen bonds leads to unique properties such as high specific heat, cohesion, and solvent capabilities.

Question 2

A scientist is testing the effect of a new fertilizer on plant growth. She sets up two groups: one receives the fertilizer, and the other does not. She measures plant height weekly. In this experiment, which is the dependent variable?

Accepted Answer

The height of the plants

Question 3

Which of the following best describes the difference between covalent and ionic bonds?

Accepted Answer

Covalent bonds involve the sharing of electrons, while ionic bonds involve the transfer of electrons.

Question 4

A patient is diagnosed with acidosis, meaning their blood pH is below normal. Which of the following best explains how the bicarbonate buffer system helps maintain pH homeostasis in this situation?

Accepted Answer

Bicarbonate ions ($$ \mathrm{$$HCO_3$$^-} ) $$combine with excess hydrogen ions ($$ \mathrm{H^+} ) to $$form carbonic acid ($$ \mathrm{H_2CO_3} $$), which reduces the concentration of free $$ \mathrm{H^+} .$$

Question 5

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy of a reaction, increasing the reaction rate.

Question 6

A cell is placed in a hypertonic solution. What will most likely happen to the cell?

Accepted Answer

Water will move out of the cell, causing it to shrink (crenate or plasmolyze).

Question 7

Which of the following best describes the role of cholesterol in animal cell membranes?

Accepted Answer

Cholesterol increases membrane fluidity at low temperatures and decreases fluidity at high temperatures.

Question 8

Which of the following is an example of an emergent property of water that is critical for life?

Accepted Answer

Water's high specific heat, which helps moderate Earth's climate

Question 9

A protein is denatured by heat. Which level(s) of protein structure are most likely disrupted?

Accepted Answer

Secondary, tertiary, and quaternary structures

Question 10

Which of the following best explains why DNA is a better molecule for long-term genetic information storage than RNA?

Accepted Answer

DNA is double-stranded and contains deoxyribose, making it more chemically stable than RNA.

Question 11

Which of the following best describes the function of the sodium-potassium pump in animal cells?

Accepted Answer

It uses ATP to move sodium ions out of the cell and potassium ions into the cell, maintaining electrochemical gradients.

Question 12

Which of the following statements about the central dogma of molecular biology is correct?

Accepted Answer

Information flows from DNA to RNA to protein.

Question 13

A mutation changes a hydrophobic amino acid in a protein to a hydrophilic one. Which of the following is a likely consequence?

Accepted Answer

The protein's tertiary structure may be altered, affecting its function.

Question 14

Which of the following best describes the difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have a nucleus and membrane-bound organelles; prokaryotic cells lack both.

Question 15

Which of the following is a correct statement about the laws of thermodynamics as they apply to living organisms?

Accepted Answer

Living organisms convert energy from one form to another, but cannot create or destroy energy ($$ \Delta E = 0 ).$$

Question 16

Which of the following best explains why phospholipids form bilayers in water?

Accepted Answer

Their hydrophilic heads interact with water, while hydrophobic tails avoid water, resulting in a bilayer.

Question 17

A scientist wants to test whether a new drug affects heart rate in mice. She randomly assigns mice to two groups: one receives the drug, the other receives a placebo. She measures heart rate after treatment. Which of the following best describes the placebo group?

Accepted Answer

The placebo group is the control group, used for comparison.

Question 18

Which of the following best describes the function of ribosomes in a cell?

Accepted Answer

Ribosomes are the site of protein synthesis, translating mRNA into polypeptides.

Question 19

Which of the following is a correct statement about the structure of ATP?

Accepted Answer

ATP consists of adenine, ribose, and three phosphate groups.

Question 20

Which of the following best explains why enzymes are specific to their substrates?

Accepted Answer

Enzymes have active sites with shapes complementary to specific substrates, following the induced-fit model.

General Biology: Core Concepts and Learning Objectives

Study Guide - Practice Questions

Study Guide - Flashcards