Q: Which of the following equations correctly represents aerobic cellular respiration?

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \mathrm{O}_2 \rightarrow 6 \mathrm{CO}_2 + 6 \mathrm{H}_2\mathrm{O} + \text{energy}$$

Question 1

Which of the following statements best describes the role of NAD+ in cellular respiration?

Accepted Answer

NAD+ functions as an electron carrier, accepting electrons during glycolysis and the Krebs cycle and becoming reduced to NADH.

Question 2

During aerobic respiration, what is the correct sequence of events for the breakdown of one molecule of glucose?

Accepted Answer

Glycolysis → Pyruvate oxidation → Krebs cycle → Oxidative phosphorylation

Question 3

Which of the following best explains the difference between substrate-level phosphorylation and oxidative phosphorylation?

Accepted Answer

Substrate-level phosphorylation directly transfers a phosphate group from a substrate to ADP, while oxidative phosphorylation uses the energy from a proton gradient generated by the electron transport chain to produce ATP.

Question 4

Which of the following equations correctly represents aerobic cellular respiration?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \mathrm{O}_2 ightarrow 6 \mathrm{CO}_2 + 6 \mathrm{H}_2\mathrm{O} + 	ext{energy}$$

Question 5

In the electron transport chain (ETC) of mitochondria, what is the immediate source of energy used to synthesize ATP?

Accepted Answer

The proton gradient established across the inner mitochondrial membrane

Question 6

Which of the following statements about fermentation is correct?

Accepted Answer

Fermentation regenerates NAD+ by transferring electrons from NADH to pyruvate or its derivatives.

Question 7

During the breakdown of glucose in cellular respiration, how do the number of carbon atoms change from glucose to acetyl-CoA?

Accepted Answer

Glucose (6C) is split into two pyruvate (3C each), and each pyruvate loses one carbon as CO2 to form acetyl-CoA (2C each).

Question 8

Which of the following is the correct equation for photosynthesis?

Accepted Answer

$$6 \mathrm{CO}_2 + 6 \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6 \mathrm{O}_2$$

Question 9

Which molecule acts as the carbon dioxide acceptor in the Calvin cycle, and what is the name of the sugar produced in the second stage?

Accepted Answer

Ribulose-1,5-bisphosphate (RuBP); Glyceraldehyde-3-phosphate (G3P)

Question 10

Which adaptation allows CAM plants to survive in arid environments?

Accepted Answer

They open their stomata only at night to minimize water loss and fix CO2 into organic acids.

Question 11

Which of the following best describes the relationship between the light reactions and the Calvin cycle in photosynthesis?

Accepted Answer

The light reactions generate ATP and NADPH, which are then used by the Calvin cycle to fix carbon.

Question 12

Which of the following is a key difference between autotrophs and heterotrophs?

Accepted Answer

Autotrophs use light or inorganic chemicals to produce organic molecules, while heterotrophs must obtain organic molecules by consuming other organisms.

Question 13

Which pigment is primarily responsible for absorbing light energy during photosynthesis, and what is its main absorption spectrum?

Accepted Answer

Chlorophyll a; absorbs mainly blue-violet and red wavelengths

Question 14

During which phase of mitosis do sister chromatids separate and move toward opposite poles of the cell?

Accepted Answer

Anaphase

Question 15

A patient’s muscle cells are deprived of oxygen. Which process will allow the cells to continue producing ATP, and what is the likely byproduct?

Accepted Answer

Lactic acid fermentation; lactic acid

Question 16

Which of the following best describes photorespiration?

Accepted Answer

A process in which RuBisCO fixes O2 instead of CO2, leading to the consumption of ATP and release of CO2 without producing sugar.

Question 17

Which of the following statements about the electron transport chain (ETC) in mitochondria is correct?

Accepted Answer

The ETC pumps protons from the mitochondrial matrix to the intermembrane space, creating a proton gradient.

Question 18

Which of the following is true regarding the final electron acceptor in aerobic and anaerobic respiration?

Accepted Answer

Nitrate, sulfate, or other molecules serve as final electron acceptors in anaerobic respiration, while oxygen is the final electron acceptor in aerobic respiration.

Question 19

During which stage of the cell cycle does DNA replication occur?

Accepted Answer

S phase

Question 20

A scientist is studying a plant that closes its stomata during the day and fixes CO2 at night. Which type of plant is this, and what is the main advantage of this adaptation?

Accepted Answer

CAM plant; reduced water loss in arid environments

General Biology Exam Study Guide: Cellular Respiration, Photosynthesis, and Cell Division

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