Question 1

The fruit ripening process releases large quantities of

Accepted Answer

Ethylene is a plant hormone known for its role in the ripening process of fruits. It acts as a signaling molecule that triggers various physiological changes, leading to the ripening of the fruit.

Question 2

The suppression of the growth of axillary or lateral buds is called

Accepted Answer

Apical dominance is the phenomenon where the main, central stem of the plant is dominant over (i.e., grows more strongly than) other side stems; it is largely regulated by plant hormones and results in the suppression of the growth of axillary (lateral) buds.

Question 3

Which of the following is synthesized from carotenoid pigments in plastids?

Accepted Answer

Abscisic acid is synthesized from carotenoid pigments in plastids. This process involves the cleavage of carotenoids to produce the precursor of abscisic acid, which is then converted into the active hormone.

Question 4

Which of the following statements is correct?

Accepted Answer

Turgor movements, which are rapid movements in response to stimuli, were indeed the basis for Linnaeus' garden clock, where different flowers open or close at specific times of the day.

Question 5

Plants that have two critical photoperiods in order to flower are called

Accepted Answer

Intermediate-day plants require two specific photoperiods, one for the minimum and another for the maximum, to initiate flowering.

Question 6

Differentiation refers to changes in the structure of a cell so that it can perform a specific function.

Accepted Answer

Differentiation is the process by which a cell changes from one cell type to another, usually becoming more specialized in its structure and function.

Question 7

Special cells that facilitate the perception of gravity by root caps and coleoptiles are

Accepted Answer

The answer of Special cells that facilitate the perception of...

Question 8

The most important effect of cytokinin is its influence on

Accepted Answer

Cytokinins are a class of plant hormones that promote cell division, or cytokinesis, in plant roots and shoots. They are involved in various aspects of plant growth and development, including stimulating cell division.

Question 9

The movement of a leaf blade on its petiole to keep the blade oriented perpendicular to the sun's rays throughout the day is facilitated by

Accepted Answer

Motor cells are responsible for the movement of plant parts, such as the orientation of leaf blades to maximize photosynthesis by keeping them perpendicular to the sun's rays throughout the day. This movement is a type of tropism called phototropism, where plants grow or move in response to light.

Question 10

A reduction in the elongation of stems subject to mechanical stresses is called

Accepted Answer

Thigmomorphogenesis is the term used to describe changes in plant growth patterns, such as a reduction in stem elongation, in response to mechanical stress (e.g., wind or touch).

Question 11

This plant pigment has two forms; one form absorbs red light and is then converted into the second form that absorbs far-red light. The second form, after absorption of far-red light, is converted back into the red absorbing form. This pigment is

Accepted Answer

Phytochrome is the plant pigment that exists in two forms: one that absorbs red light and another that absorbs far-red light. These forms are interconvertible, depending on the light they absorb. This characteristic of phytochrome plays a crucial role in regulating plant development processes such as seed germination and flowering.

Question 12

Which of the following is used by nurseries to cause active plants to become dormant?

Accepted Answer

Abscisic acid is known for its role in inducing dormancy in plants, especially in response to environmental stress conditions such as drought. It helps plants conserve water by closing stomata and halts growth processes, effectively causing the plant to become dormant.

Question 13

Which of the following play a major role in water-conservation movements of grasses?

Accepted Answer

Bulliform cells, which are large, bubble-shaped epidermal cells found in the leaves of many grasses, play a significant role in the water-conservation movements of these plants. They help in the rolling and unrolling of leaves in response to changes in water availability, thereby reducing water loss through transpiration.

Question 14

Absicsic acid is associated with maintaining ________ in buds and seeds.

Accepted Answer

Abscisic acid is a plant hormone that plays a crucial role in maintaining dormancy in buds and seeds, helping to ensure that they only germinate or break dormancy under favorable conditions.

Question 15

Plant movements that are not oriented relative to the direction of the stimulus are called

Accepted Answer

Nastic movements in plants are non-directional responses to stimuli, meaning the direction of the response does not depend on the direction from which the stimulus originates, unlike tropisms which are directional responses.

Question 16

Which of the following plant movements is due solely to an external stimulus?

Accepted Answer

Gravitropism is a plant movement that occurs in response to gravity, an external stimulus.

Question 17

There probably is only one auxin naturally produced by plants.

Accepted Answer

Plants produce several types of auxins, with indole-3-acetic acid (IAA) being the most common and well-studied, but not the only one.

Question 18

Which of the following is a simple device that rotates a potted plant slowly about a horizontal axis?

Accepted Answer

A clinostat is a device used to rotate plants slowly about a horizontal axis to negate the effects of gravity on plant growth.

Question 19

Which of the following is an effect of light on auxin?

Accepted Answer

Auxin, a plant hormone, tends to migrate away from light sources, leading to differential growth rates on the shaded side of the plant. This causes the plant to bend towards the light, a phenomenon known as phototropism.

Question 20

The flowering of Arabidopsis is a result of turning on a gene called ________ which produces of a protein that moves from the leaves to the buds to initiate flowering.

Accepted Answer

The answer of The flowering of Arabidopsis is a result...

Quiz 11: Growth