Question 1

A horticulturalist who wants to induce flowering in a crop of short-day plants should carry out the induction

Accepted Answer

Short-day plants, also known as long-night plants, require a certain amount of uninterrupted darkness to initiate flowering. Therefore, the induction should be carried out when the day length is below a critical maximum. This typically occurs in the fall and winter months, when the nights are longer than the days. The other options listed do not provide the necessary conditions for inducing flowering in short-day plants.

Question 2

The ability of plants to measure night length was determined by experiments in which

Accepted Answer

Plants are able to measure night length through the process of photoperiodism, in which they are able to detect changes in the length of the day and night cycle. Experimentally, plants have been grown in dark periods that were interrupted with brief pulses of light to determine their ability to sense the length of the night. This method is known as the interrupted dark period technique and allows for the study of the effect of light treatment timing and intensity on plant growth and development.

Question 3

An SDP plant flowers when

Accepted Answer

In plants, the ratio of red light (P_fr) to far-red light (P_r) is detected by phytochrome photoreceptors to determine the length of the night (dark period) and initiate flowering. When the ratio of P_fr to P_r is sufficiently low, it indicates a long night and triggers the flowering process. Therefore, option B is the correct answer as it states that the SDP (Short Day Plant) will flower when the ratio of P_fr to P_r is sufficiently low.

Question 4

A plant's transition to a flowering state is often marked by a(n)

Accepted Answer

When a plant transitions to a flowering state, it typically decreases in vegetative growth as it redirects its energy towards reproducing. This process is triggered by factors such as changes in day length or environmental cues.

Question 5

In a short-day plant like cocklebur,which has a critical day length of 15 hours,flowering could be induced by _______ hours of light alternating with _______.

Accepted Answer

Short-day plants flower when the day length is shorter than their critical day length. 12 hours of light with 12 hours of darkness is below the 15-hour critical day length, inducing flowering.

Question 6

Which of the following would most likely happen if a repressor to APETALA1 were overexpressed in shoot apical meristems throughout the plant?

Accepted Answer

Overexpression of a repressor to APETALA1, a gene crucial for the initiation of flowering, would likely prevent flowering regardless of environmental conditions.

Question 7

To stage long-day plants so they will produce blooms for a flower show,what can a greenhouse manager provide to the plants to prevent flowering?

Accepted Answer

Long-day plants require a short period of darkness to trigger flowering. Therefore, to prevent flowering in long-day plants, the greenhouse manager can provide them with a long, uninterrupted period of darkness.

Question 8

Technically,short-day plants flower when the _______ period _______ a critical maximum.

Accepted Answer

Short-day plants flower when the day period is shorter than a critical maximum.

Question 9

A vegetative meristem must _______ in order to begin switching to floral development.

Accepted Answer

Meristem identity genes are responsible for regulating the transition from vegetative to floral development in plants. Without the influence of these genes, the vegetative meristem will continue to produce vegetative growth rather than transitioning to flower production.

Question 10

You are asked to identify the version of florigen found in carnivorous sundew plants.You decide to start by using biochemical methods to separate different macromolecules to isolate the florigen,because it is a(n)

Accepted Answer

Florigen is a plant hormone that is responsible for flowering, and it is known to be a protein molecule. Therefore, the best choice is D) protein.

Question 11

A conifer is found with homologs of the genes that determine the location of floral parts in the flower.These are homologs of _______ genes.

Accepted Answer

The genes that determine the location of floral parts in a flower are known as floral organ identity genes. These genes play a crucial role in specifying the identity of each floral organ, such as sepals, petals, stamens, and carpels. The fact that a conifer has homologs of these genes suggests that they are involved in the development of reproductive structures in this plant. Option A, meristem identity genes, are involved in the initiation and maintenance of the shoot apical meristem, while option B, whorl genes, are involved in controlling the number and arrangement of floral organs in different whorls. Option C, flowering time genes, regulate the timing and onset of flowering, while option D, apical genes, play a role in the growth and development of the apical meristem.

Question 12

A new kind of mustard is found to flower with any length of day or night as long as it is at least two months old.What kind of plant is this?

Accepted Answer

The mustard described flowers regardless of day length, indicating it is day-neutral, which is not listed among the options.

Question 13

For plants that flower in response to photoperiodic stimuli,the most critical determinant in the light-dark cycle is the

Accepted Answer

The most critical determinant for plants that flower in response to photoperiodic stimuli is the length of uninterrupted dark. This period is crucial for the plant's perception of day length, which in turn influences flowering time.

Question 14

Experiments have shown that when a short-day plant (SDP)and a long-day plant (LDP)are grafted together and the SDP is exposed to a photoperiod that causes it to flower,the LDP also flowers.This suggests that a specific flower-initiating hormone is produced in plants.A properly controlled experiment would also

Accepted Answer

A properly controlled experiment would include grafting the two plants without inducing the SDP to ensure that the flowering of the LDP is due to the hormone produced by the SDP when it flowers, rather than other factors.

Question 15

Even if a plant receives an inductive stimulus that would normally lead to flowering,the flowering may be prevented by a quick removal of the

Accepted Answer

Leaves are responsible for perceiving the inductive stimulus for flowering, and their removal can prevent the flowering process.

Question 16

When a vegetative apical meristem ceases production of leaves and axillary buds and instead produces structures such as bracts,it has become a(n)

Accepted Answer

An inflorescence meristem is responsible for the transition from vegetative growth to reproductive growth, including the production of structures such as bracts, which are associated with flowers or flower clusters.

Question 17

Flowers can occur singly or in an orderly cluster known as a(n)

Accepted Answer

The term for an orderly cluster of flowers is inflorescence, making choice A the correct answer. Choices B, C, D, and E are not accurate terms for this concept.

Question 18

After an apical meristem has been redirected toward developing into a floral meristem,_______ are responsible for further refinement of the floral development pathway.

Accepted Answer

Floral organ identity genes, such as the ABC model genes, are responsible for controlling the development of specific floral organs and refining the floral development pathway. Hormones and light signals may play a role in floral development, but they do not specifically refine the pathway. Other mature floral meristems may also contribute to floral development, but this is not a necessary step in the refinement of the pathway.

Question 19

Which of the following is not a pattern of plant flowering?

Accepted Answer

Annual, biennial, and perennial are all patterns of plant flowering. Diapausal is not a pattern of plant flowering but rather an interruption in development or growth in response to environmental cues.

Question 20

Short-day plants bloom

Accepted Answer

The answer of Short-day plants bloom
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Quiz 27: Reproduction of Flowering Plants