Q: Which of the following equations correctly represents the net ATP yield from glycolysis per molecule of glucose?

$$2 \text{ ADP} + 2 \text{ P}_i + 2 \text{ NAD}^+ + \text{glucose} \rightarrow 2 \text{ ATP} + 2 \text{ NADH} + 2 \text{ pyruvate} + 2 \text{ H}_2\text{O}$$

Q: During strenuous exercise, muscle cells switch to lactic acid fermentation. What is the primary benefit of this process?

It regenerates $$\text{NAD}^+$$, allowing glycolysis to continue.

Q: Which of the following scenarios would most likely increase photorespiration in a C3 plant?

High $$\text{O}_2$$ concentration

Question 1

Which of the following best explains why enzymes are essential for life at normal body temperatures?

Accepted Answer

They lower the activation energy, allowing reactions to proceed rapidly at physiological temperatures.

Question 2

A scientist adds a competitive inhibitor to an enzyme-catalyzed reaction. Which of the following changes would most likely restore the original reaction rate?

Accepted Answer

Increasing the substrate concentration.

Question 3

Which of the following equations correctly represents the net ATP yield from glycolysis per molecule of glucose?

Accepted Answer

$$2 	ext{ ADP} + 2 	ext{ P}_i + 2 	ext{ NAD}^+ + 	ext{glucose} ightarrow 2 	ext{ ATP} + 2 	ext{ NADH} + 2 	ext{ pyruvate} + 2 	ext{ H}_2	ext{O}$$

Question 4

A patient with a mitochondrial disorder cannot efficiently convert pyruvate to acetyl CoA. Which process would be directly impaired?

Accepted Answer

Krebs cycle in the mitochondrial matrix

Question 5

Which of the following best describes the role of NADH in cellular respiration?

Accepted Answer

It carries high-energy electrons to the electron transport chain.

Question 6

During strenuous exercise, muscle cells switch to lactic acid fermentation. What is the primary benefit of this process?

Accepted Answer

It regenerates $$	ext{NAD}^+$$, allowing glycolysis to continue.

Question 7

Which of the following best explains why oxygen is required for the electron transport chain to function?

Accepted Answer

Oxygen acts as the final electron acceptor, forming water.

Question 8

A plant is exposed to an atmosphere containing only $$^{18}	ext{O}-$$labeled water and normal $$	ext{CO}_2. $$Which molecule will contain the $$^{18}	ext{O}$$ label after photosynthesis?

Accepted Answer

Oxygen gas ($$	ext{O}_2)$$

Question 9

Which of the following correctly matches the process with its location in the cell?

Accepted Answer

Calvin cycle – stroma of the chloroplast

Question 10

A mutation causes RUBISCO to lose its function. Which process would be directly affected?

Accepted Answer

Carbon fixation in the Calvin cycle

Question 11

Which of the following scenarios would most likely increase photorespiration in a C3 plant?

Accepted Answer

High $$	ext{O}_2$$ concentration

Question 12

Which of the following best explains how C4 plants minimize photorespiration?

Accepted Answer

They spatially separate initial $$	ext{CO}_2$$ fixation from the Calvin cycle.

Question 13

A cell fails to pass the G1 checkpoint due to insufficient nutrients. What is the most likely outcome?

Accepted Answer

The cell will not enter S phase and may enter G0.

Question 14

Which event during meiosis increases genetic diversity by exchanging genetic material between homologous chromosomes?

Accepted Answer

Crossing over during prophase I

Question 15

A cell with 2n = 46 chromosomes undergoes meiosis. How many chromosomes will each resulting gamete contain?

Accepted Answer

23

Question 16

Which of the following best describes the outcome of nondisjunction during meiosis?

Accepted Answer

Some gametes have abnormal numbers of chromosomes (aneuploidy).

Question 17

Which checkpoint ensures that all chromosomes are properly attached to the spindle before the cell proceeds to anaphase?

Accepted Answer

Metaphase checkpoint

Question 18

Which of the following best explains why cancer can result from the failure of cell cycle checkpoints?

Accepted Answer

Cells divide uncontrollably due to unchecked DNA damage or errors.

Question 19

Which of the following equations best represents the process of oxidative phosphorylation in the electron transport chain?

Accepted Answer

$$	ext{NADH} + 	ext{H}^+ + 1/2 	ext{O}_2 ightarrow 	ext{NAD}^+ + 	ext{H}_2	ext{O}$$

Question 20

Which of the following is a direct result of chemiosmosis in mitochondria?

Accepted Answer

Synthesis of ATP from ADP and $$	ext{P}_i by $$ATP synthase

BIO 1 Exam 3 Practice – Step-by-Step Study Guidance

Study Guide - Practice Questions

Study Guide - Flashcards