Q: Which of the following is a correct equation for the conversion of starch to sugar during fruit ripening, promoted by ethylene?

$$\text{(C}_6\text{H}_{10}\text{O}_5\text{)}_n + n\,\text{H}_2\text{O} \rightarrow n\,\text{C}_6\text{H}_{12}\text{O}_6$$

Question 1

Which plant hormone is primarily responsible for promoting cell elongation on the shaded side of a stem during phototropism, causing the plant to bend toward light?

Accepted Answer

Auxin

Question 2

A gardener notices that after removing the shoot tip of a plant, the lateral buds begin to grow more vigorously. Which hormone interaction best explains this phenomenon?

Accepted Answer

Decrease in auxin and increase in cytokinin activity

Question 3

Which of the following best describes the role of abscisic acid (ABA) during drought stress in plants?

Accepted Answer

ABA promotes stomatal closure to reduce water loss

Question 4

A citrus farmer applies ethylene to harvested oranges. What is the most likely outcome, considering oranges are non-climacteric fruits?

Accepted Answer

The oranges will change color but not ripen further

Question 5

Which of the following is a non-directional, rapid movement in plants in response to touch, as seen in Mimosa pudica?

Accepted Answer

Thigmonasty

Question 6

Which hormone is most directly involved in breaking seed dormancy and promoting germination by stimulating the synthesis of hydrolytic enzymes?

Accepted Answer

Gibberellin

Question 7

A plant's tendril wraps around a nearby support structure after contact. Which process and hormone are primarily responsible for this behavior?

Accepted Answer

Thigmotropism and auxin

Question 8

Which plant hormone is most associated with promoting fruit ripening, leaf senescence, and response to mechanical stress?

Accepted Answer

Ethylene

Question 9

A scientist observes that a plant's leaves close rapidly when touched, but the movement is not directional. What is the term for this type of movement?

Accepted Answer

Seismonasty

Question 10

Which of the following best describes the role of jasmonates in plants?

Accepted Answer

Mediate plant defense responses and regulate senescence

Question 11

A plant is exposed to a chemical gradient in the soil, and its roots grow toward the higher concentration of nutrients. What is this response called?

Accepted Answer

Chemotropism

Question 12

Which hormone is primarily responsible for delaying leaf senescence and promoting shoot growth?

Accepted Answer

Cytokinin

Question 13

Which of the following is a correct equation for the conversion of starch to sugar during fruit ripening, promoted by ethylene?

Accepted Answer

$$	ext{(C}_6	ext{H}_{10}	ext{O}_5	ext{)}_n + n\,	ext{H}_2	ext{O} ightarrow n\,	ext{C}_6	ext{H}_{12}	ext{O}_6$$

Question 14

Which of the following best explains why phytochromes are important for seed germination and flowering?

Accepted Answer

They are light-sensitive pigments that detect changes in light quality and duration

Question 15

A plant is exposed to a short day and long night cycle. Which process is most likely to be affected, and which pigment is involved?

Accepted Answer

Photoperiodism; phytochrome

Question 16

Which hormone is most directly involved in promoting tolerance to cold, drought, and salt stress in plants?

Accepted Answer

Brassinosteroids

Question 17

Which of the following is an example of a plant's defense mechanism mediated by salicylic acid?

Accepted Answer

Systemic acquired resistance to pathogen infection

Question 18

A Venus Flytrap closes its leaves rapidly when an insect lands on it. What type of movement is this, and what is its biological significance?

Accepted Answer

Thigmonastic movement; defense and prey capture

Question 19

Which of the following best describes the process of signal transduction in plant cells?

Accepted Answer

Proteins on cell membranes recognize and bind to specific molecules, initiating chemical changes

Question 20

Which of the following is a correct example of a multi-step plant response integrating multiple hormones and environmental cues?

Accepted Answer

A seed exposed to water and light breaks dormancy (ABA decreases), produces gibberellin to stimulate enzyme synthesis, and uses phytochrome to regulate germination timing.

Plant Physiology: Plant Hormones and Movement

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