Q: Which equation best represents the acid growth hypothesis for cell elongation?

$$\text{Auxin} \rightarrow \text{Proton Pump Activation} \rightarrow \text{Cell Wall pH Decrease} \rightarrow \text{Expansin Activation} \rightarrow \text{Cell Elongation}$$

Question 1

Which of the following best describes the sequence of events in plant signal transduction?

Accepted Answer

Reception \rightarrow Transduction \rightarrow Response

Question 2

During de-etiolation, which cellular process is primarily activated by light in plants?

Accepted Answer

Gene expression for greening proteins

Question 3

Which hormone is most directly involved in the acid growth hypothesis, leading to cell elongation?

Accepted Answer

Auxin

Question 4

A plant exposed to light will show which of the following developmental changes compared to a plant grown in darkness?

Accepted Answer

Expanded green leaves and stronger roots

Question 5

In the classic phototropism experiment, what happens when the coleoptile tip is removed?

Accepted Answer

No curvature occurs

Question 6

Which of the following is a correct statement about plant hormone interactions?

Accepted Answer

Hormone interactions are more important than isolated hormone effects

Question 7

What is the role of cGMP and $$Ca^{2+} in $$the de-etiolation signaling pathway?

Accepted Answer

They act as second messengers to relay the signal

Question 8

Which hormone is primarily responsible for maintaining apical dominance by suppressing axillary bud growth?

Accepted Answer

Auxin

Question 9

A seed begins to germinate after water enters. Which hormone is released by the embryo to mobilize nutrients?

Accepted Answer

Gibberellin (GA)

Question 10

Which equation best represents the acid growth hypothesis for cell elongation?

Accepted Answer

$$	ext{Auxin} ightarrow 	ext{Proton Pump Activation} ightarrow 	ext{Cell Wall pH Decrease} ightarrow 	ext{Expansin Activation} ightarrow 	ext{Cell Elongation}$$

Question 11

Which hormone is most likely to promote branching by counteracting apical dominance?

Accepted Answer

Cytokinin

Question 12

If a plant is exposed to drought, which hormone is most likely to increase to help the plant cope?

Accepted Answer

Abscisic acid (ABA)

Question 13

Which of the following best explains why a coleoptile bends toward light?

Accepted Answer

Auxin accumulates on the shaded side, causing faster growth there

Question 14

Which hormone is most directly involved in fruit ripening and leaf abscission?

Accepted Answer

Ethylene

Question 15

A plant's response to touch, such as closing leaves when touched, is an example of which type of signal?

Accepted Answer

External mechanical signal

Question 16

Which hormone is most likely to be involved in the mobilization of nutrients from the endosperm to the embryo during seed germination?

Accepted Answer

Gibberellin (GA)

Question 17

Which of the following is a plausible outcome if a plant's phytochrome receptor is nonfunctional?

Accepted Answer

The plant will fail to undergo de-etiolation in response to light

Question 18

Which hormone is most likely to inhibit seed germination and promote dormancy?

Accepted Answer

Abscisic acid (ABA)

Question 19

Which of the following best describes the role of strigolactones in plant development?

Accepted Answer

Repress axillary bud growth and regulate mycorrhizal interactions

Question 20

A plant exposed to both auxin and cytokinin will most likely exhibit which of the following?

Accepted Answer

Enhanced branching due to cytokinin counteracting auxin

L11Signal Transduction and Plant Hormones: Plant Responses to Internal and External Signals

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