Question 1

Which of the following best describes the role of chlorophyll in photosynthesis?

Accepted Answer

Chlorophyll absorbs visible light, primarily in the red and blue regions, and transfers the energy to electrons used in the light reactions.

Question 2

Which equation correctly summarizes the overall process of photosynthesis?

Accepted Answer

$$6 \mathrm{CO}_2 + 6 \mathrm{H}_2O \rightarrow C_6H_{12}O_6$ + 6 \mathrm{O}_2$$

Question 3

Which of the following statements about autotrophic and heterotrophic nutrition is correct?

Accepted Answer

Autotrophs synthesize organic molecules from inorganic raw materials, while heterotrophs obtain organic molecules by consuming other organisms.

Question 4

During the light reactions of photosynthesis, what is the primary function of NADP$$^+$$?

Accepted Answer

NADP$$^+ is $$reduced to NADPH, which temporarily stores energized electrons for use in the Calvin cycle.

Question 5

Which structure within the chloroplast is the site of the light-dependent reactions?

Accepted Answer

Thylakoid membrane

Question 6

What is the role of RuBP carboxylase (rubisco) in the Calvin cycle?

Accepted Answer

It catalyzes the fixation of CO$$_2 to $$ribulose bisphosphate (RuBP), forming an unstable six-carbon intermediate.

Question 7

If a plant is exposed only to green light, what would you expect to happen to its rate of photosynthesis?

Accepted Answer

The rate of photosynthesis would decrease because chlorophyll reflects green light and absorbs little of it.

Question 8

Which of the following is a direct product of the Calvin cycle?

Accepted Answer

Glyceraldehyde 3-phosphate (G3P)

Question 9

Why do non-photosynthetic parts of plants (such as roots) depend on photosynthetic parts?

Accepted Answer

Non-photosynthetic parts depend on organic molecules exported from leaves for energy and biosynthesis.

Question 10

Which of the following best explains why ATP is required in the Calvin cycle?

Accepted Answer

ATP supplies the chemical energy required for the synthesis of organic molecules from CO$$_2.$$

Question 11

A scientist uses a spectrophotometer to measure the absorption spectrum of a pigment. What information does this provide?

Accepted Answer

The wavelengths of light that are absorbed by the pigment.

Question 12

Which of the following is NOT a product of the light reactions of photosynthesis?

Accepted Answer

Glucose

Question 13

Which process occurs in the stroma of the chloroplast?

Accepted Answer

Calvin cycle (carbon fixation)

Question 14

How many turns of the Calvin cycle are required to produce one molecule of glucose ($$C_6H_{12}O_6$)?

Accepted Answer

Six

Question 15

Which of the following statements about photoautotrophs is correct?

Accepted Answer

Photoautotrophs use light energy to synthesize organic molecules from CO$$_2$$ and H$$_2O.$$

Question 16

Which of the following is a reason why plants store extra sugars as starch?

Accepted Answer

Starch provides a stable storage form for energy that can be used later for growth and metabolism.

Question 17

Which of the following is true about the fate of oxygen produced during photosynthesis?

Accepted Answer

Oxygen is produced during the light reactions from the splitting of water molecules.

Question 18

Which pigment is primarily responsible for the absorption of light in the light reactions of photosynthesis?

Accepted Answer

Chlorophyll a

Question 19

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

Accepted Answer

The light reactions produce ATP and NADPH, which are used in the Calvin cycle to fix carbon.

Lecture 9 - Photosynthesis: Mechanisms, Nutrition Types, and Pigments

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