Question 1

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

Accepted Answer

A hormone binds to a receptor, triggering a series of molecular events that lead to a cellular response.

Question 2

A seedling bends toward a light source due to the asymmetric distribution of which hormone?

Accepted Answer

Auxin

Question 3

Which of the following is a correct statement about the acid-growth hypothesis?

Accepted Answer

Proton pumps move $$\mathrm{H^+}$$ into the cell wall, activating expansins that loosen cellulose fibers.

Question 4

A plant exposed to far-red light will most likely:

Accepted Answer

Inhibit seed germination due to phytochrome photoreversibility.

Question 5

Which of the following best explains why a plant bends toward light (phototropism)?

Accepted Answer

Auxin accumulates on the shaded side, causing those cells to elongate more than cells on the lighted side.

Question 6

Which hormone is primarily responsible for promoting cell division in plant roots and shoots?

Accepted Answer

Cytokinins

Question 7

A plant that flowers only when nights are longer than a critical length is classified as a:

Accepted Answer

Short-day plant

Question 8

Which of the following is a direct result of ethylene production in plants?

Accepted Answer

Fruit ripening and leaf abscission

Question 9

A plant's response to touch, such as the closing of a Venus flytrap, is an example of:

Accepted Answer

Thigmotropism

Question 10

Which of the following best describes the statolith hypothesis for gravitropism?

Accepted Answer

Dense, starch-filled organelles sink to the bottom of cells, triggering a growth response to gravity.

Question 11

Which hormone is most closely associated with seed dormancy and the inhibition of germination?

Accepted Answer

Abscisic acid (ABA)

Question 12

A plant is exposed to a pathogen and rapidly kills its own cells at the infection site. This is an example of:

Accepted Answer

Hypersensitive response

Question 13

Which of the following is a secondary metabolite used by plants to deter herbivores?

Accepted Answer

Alkaloids

Question 14

Which of the following best explains why bananas ripen faster when stored together?

Accepted Answer

Ethylene gas produced by ripening bananas accelerates the ripening of nearby fruit.

Question 15

Which process is regulated by the ratio of cytokinins to auxin in plants?

Accepted Answer

Apical dominance

Question 16

A plant's leaves are exposed to red light, then immediately to far-red light. What is the likely outcome for seed germination?

Accepted Answer

Germination will be inhibited due to the conversion of phytochrome to its inactive form.

Question 17

Which of the following is an example of systemic acquired resistance in plants?

Accepted Answer

Production of methyl salicylate at the infection site, which is transported throughout the plant to induce resistance.

Question 18

Which of the following best describes the role of proteinase inhibitors in plant defense?

Accepted Answer

They block digestive enzymes in herbivores, reducing the ability to digest plant tissue.

Question 19

Which hormone is most directly involved in the induction of seed germination?

Accepted Answer

Gibberellins

Question 20

A plant's tendril wraps around a support structure after contact. Which process is responsible for this movement?

Accepted Answer

Thigmotropism

Plant Sensory Systems, Signals, and Responses: Mini-Study Guide

Study Guide - Practice Questions