Question 1

Which of the following best explains why ice floats on liquid water, and why this property is crucial for aquatic life in cold climates?

Accepted Answer

Ice is less dense than liquid water due to hydrogen bonds forming a crystalline lattice, which insulates water below and allows aquatic life to survive during freezing temperatures.

Question 2

A scientist is testing the effect of a new fertilizer on plant growth. She sets up two groups: one receives the fertilizer, the other does not. She measures plant height weekly. Which aspect of the scientific method is best represented by the group that does NOT receive fertilizer?

Accepted Answer

The control group, which serves as a baseline for comparison.

Question 3

Which of the following scenarios correctly applies the concept of homeostasis?

Accepted Answer

A human sweats to cool down when body temperature rises above normal, maintaining internal temperature.

Question 4

Which statement accurately describes the difference between covalent and ionic bonds?

Accepted Answer

Covalent bonds involve the sharing of electrons between atoms, while ionic bonds involve the transfer of electrons from one atom to another.

Question 5

A solution has a pH of 4. What is the concentration of hydrogen ions $$[H^+] in $$this solution, and is it acidic or basic? Use the formula $$pH = -\log_{10}[H^+].$$

Accepted Answer

$$[H^+] = 10$$^{-4}$$ \ \mathrm{M}$$; the solution is acidic.

Question 6

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

Accepted Answer

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

Question 7

A patient is diagnosed with a genetic disorder caused by a mutation in the gene encoding a lysosomal enzyme. Which cellular process is most likely to be directly affected?

Accepted Answer

Breakdown of macromolecules within the cell.

Question 8

Which of the following best describes the role of ATP in cellular metabolism?

Accepted Answer

ATP acts as an energy currency, providing energy for cellular processes by releasing a phosphate group: $$\mathrm{ATP} \rightarrow \mathrm{ADP} + \mathrm{P_i}.$$

Question 9

During aerobic cellular respiration, which stage produces the most ATP, and where does this process occur?

Accepted Answer

Electron transport chain and chemiosmosis; inner mitochondrial membrane.

Question 10

A plant is exposed to light, but its thylakoid membranes are damaged. Which process will be most directly impaired?

Accepted Answer

Production of ATP and NADPH during the light reactions.

Question 11

Which of the following best illustrates the difference between transcription and translation in eukaryotic cells?

Accepted Answer

Transcription occurs in the nucleus and produces mRNA; translation occurs in the cytoplasm at ribosomes and synthesizes proteins.

Question 12

A cell is placed in a solution and water moves into the cell, causing it to swell. Which term best describes the tonicity of the solution relative to the cell?

Accepted Answer

Hypotonic

Question 13

Which of the following mutations would most likely result in a nonfunctional protein?

Accepted Answer

A nonsense mutation that introduces a premature stop codon.

Question 14

Which process increases genetic variation during meiosis?

Accepted Answer

Crossing over between homologous chromosomes during prophase I.

Question 15

A woman who is a carrier for an X-linked recessive disorder and a man who does not have the disorder have a son. What is the probability that their son will have the disorder?

Accepted Answer

50%

Question 16

Which of the following best describes the function of Rubisco in photosynthesis?

Accepted Answer

It catalyzes the fixation of carbon dioxide in the Calvin cycle.

Question 17

Which of the following is a correct sequence of events in cell signaling?

Accepted Answer

Reception → transduction → response

Question 18

A cell with a defective Na⁺/K⁺ pump would have difficulty maintaining which of the following?

Accepted Answer

Electrochemical gradients across the plasma membrane

Question 19

Which of the following statements about gene expression in eukaryotes is correct?

Accepted Answer

Alternative splicing allows a single gene to produce multiple protein variants.

Question 20

A researcher finds that a certain protein is only present in the cytoplasm during the G2 phase of the cell cycle. Which regulatory mechanism is most likely responsible for this observation?

Accepted Answer

Cyclin-dependent kinases (Cdks) activating the protein only during G2.

Cumulative Biology Study Guide: Core Concepts from Chapters 1–16 & 26

Study Guide - Practice Questions

Study Guide - Flashcards