Question 1

Which of the following best describes the primary function of chloroplasts in plant cells?

Accepted Answer

To convert light energy into chemical energy via photosynthesis

Question 2

Autotrophs differ from heterotrophs in which of the following ways?

Accepted Answer

Autotrophs produce their own food using inorganic substances and light energy

Question 3

During photosynthesis, which molecule is oxidized and which is reduced?

Accepted Answer

H$$_2O is $$oxidized and CO$$_2 is $$reduced

Question 4

Which chemical equation correctly represents the overall process of photosynthesis?

Accepted Answer

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6$ + 6O_2$$

Question 5

Which part of the electromagnetic spectrum is primarily responsible for driving photosynthesis?

Accepted Answer

Visible light (400–700 nm)

Question 6

Why do leaves appear green to the human eye?

Accepted Answer

Chlorophyll reflects green light and absorbs red and blue

Question 7

Which of the following best explains the role of accessory pigments in photosynthesis?

Accepted Answer

They increase the absorption range of light wavelengths

Question 8

What is the main product of the light-dependent reactions of photosynthesis that is used in the Calvin cycle?

Accepted Answer

ATP and NADPH

Question 9

During the Calvin cycle, how many CO$$_2$$ molecules are required to produce one molecule of glyceraldehyde-3-phosphate (G3P)?

Accepted Answer

3

Question 10

Which phase of the Calvin cycle involves the regeneration of ribulose-1,5-bisphosphate (RuBP)?

Accepted Answer

Regeneration phase

Question 11

Photorespiration occurs when Rubisco binds to which molecule instead of CO$$_2$$?

Accepted Answer

O$$_2$$

Question 12

Which adaptation allows CAM plants to survive in arid environments?

Accepted Answer

Opening stomata only at night to minimize water loss

Question 13

Which of the following is a major difference between chemiosmosis in chloroplasts and mitochondria?

Accepted Answer

In chloroplasts, protons flow from the thylakoid space into the stroma; in mitochondria, protons flow from the intermembrane space into the matrix

Question 14

Which of the following best describes the function of G3P produced in the Calvin cycle?

Accepted Answer

It is used to regenerate RuBP and to synthesize glucose and other organic molecules

Question 15

Which pigment is primarily responsible for absorbing light energy during photosynthesis?

Accepted Answer

Chlorophyll a

Question 16

What is the main purpose of the electron transport chain in the light-dependent reactions?

Accepted Answer

To generate a proton gradient for ATP synthesis

Question 17

Which of the following statements about C$$_4$$ plants is correct?

Accepted Answer

They minimize photorespiration by spatially separating carbon fixation and the Calvin cycle

Question 18

Which molecule acts as the final electron acceptor in the light reactions of photosynthesis?

Accepted Answer

NADP$$^+$$

Question 19

How do plants use the sugar produced during photosynthesis to power cellular work?

Accepted Answer

By converting glucose into ATP through cellular respiration

Question 20

Which of the following best explains why photorespiration is considered wasteful for most plants?

Accepted Answer

It consumes ATP and releases fixed CO$$_2$$ without producing sugars

Study Guide: Photosynthesis (Chapter 8)

Study Guide - Practice Questions