Q: Which of the following best describes the overall chemical equation for photosynthesis?

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

Question 1

Which of the following best describes the overall chemical equation for photosynthesis?

Accepted Answer

$$6CO_2 + 6H_2O + 	ext{light energy} ightarrow C_6H_{12}O_6$ + 6O_2$$

Question 2

A plant is exposed only to green light. What is the most likely outcome for its rate of photosynthesis, and why?

Accepted Answer

The rate of photosynthesis will decrease because chlorophyll does not efficiently absorb green light.

Question 3

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

Accepted Answer

Thylakoid membrane

Question 4

During the light reactions of photosynthesis, what is the main role of water ($$H_2O$$)?

Accepted Answer

To provide electrons to replace those lost by chlorophyll in photosystem II

Question 5

Which of the following best explains why plants appear green to the human eye?

Accepted Answer

Chlorophyll reflects green wavelengths of light and absorbs other wavelengths more efficiently.

Question 6

Which of the following is a correct sequence of events in the light-dependent reactions of photosynthesis?

Accepted Answer

Light absorption by photosystem II, electron transport, ATP synthesis, NADPH formation

Question 7

In the Calvin cycle, which enzyme catalyzes the fixation of carbon dioxide to ribulose bisphosphate (RuBP)?

Accepted Answer

Rubisco

Question 8

Which of the following statements about the Calvin cycle is TRUE?

Accepted Answer

It uses ATP and NADPH produced in the light reactions to fix carbon dioxide into sugars.

Question 9

A mutation prevents the formation of NADPH during the light reactions. Which process in the Calvin cycle would be directly affected?

Accepted Answer

Reduction of 3-phosphoglycerate to G3P

Question 10

Which of the following best describes the role of relay proteins in cell signaling?

Accepted Answer

They transmit the signal from the receptor to the site of cellular response through a cascade of phosphorylation events.

Question 11

A researcher adds a chemical that blocks the function of G proteins in a cell. Which type of receptor-mediated signaling would be most directly affected?

Accepted Answer

G protein-coupled receptor (GPCR) signaling

Question 12

Which of the following is an example of paracrine signaling?

Accepted Answer

A neuron releases neurotransmitters that affect a nearby muscle cell.

Question 13

Which of the following best explains the concept of signal amplification in cell signaling?

Accepted Answer

A single ligand-receptor interaction can activate many downstream molecules through an enzyme cascade.

Question 14

Which of the following is a key difference between nuclear and cytoplasmic cellular responses to signaling?

Accepted Answer

Nuclear responses involve changes in gene expression, while cytoplasmic responses involve changes in enzyme activity.

Question 15

Which of the following best describes the function of second messengers in signal transduction?

Accepted Answer

They are small molecules that relay signals from receptors to target molecules inside the cell.

Question 16

A plant cell is unable to regenerate RuBP in the Calvin cycle. Which molecule would you expect to accumulate as a result?

Accepted Answer

G3P (glyceraldehyde-3-phosphate)

Question 17

Which of the following statements about photosystems is correct?

Accepted Answer

Photosystem II is the first to absorb light and initiates the electron transport chain.

Question 18

Which of the following is a real-world example of density-dependent signaling in prokaryotes?

Accepted Answer

Bacteria producing signaling molecules to coordinate biofilm formation once a threshold concentration is reached.

Question 19

Which of the following best explains why the process of photosynthesis is considered endergonic?

Accepted Answer

It requires an input of energy (from sunlight) to build complex molecules from simpler ones.

Question 20

A scientist discovers a new plant pigment that absorbs light most efficiently at 700 nm. Which photosystem is this pigment most likely associated with?

Accepted Answer

Photosystem I (P700)

Photosynthesis and Cell Communication: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard