Question 1

In apple plants,cotyledons protect the shoot of the seedling as it grows.Eventually,the plant becomes a small deciduous tree that produces large pomaceous fruits (the apple).Based on this developmental course,one can infer that

Accepted Answer

The development of cotyledons and the production of pomaceous fruits suggest that apples are eudicots. They are also deciduous, meaning they lose their leaves annually. There is no information to suggest that they lack apical dominance or produce hormones from specialized glands.

Question 2

Which process does not occur during the earliest stages of germination?

Accepted Answer

During the earliest stages of germination, cell division has not yet occurred. The seed is taking up water, activating enzymes, increasing cellular respiration, and mobilizing food reserves in preparation for cell division and growth.

Question 3

Seeds of a plant that is native to Mexico are released in mid-spring just as their native habitat is drying out and becoming unfavorably hot.They are dormant after they are released.This example demonstrates that seed dormancy usually helps ensure that

Accepted Answer

Seed dormancy helps ensure that germination occurs at a favorable time for the plant, such as after a period of cold weather or when environmental conditions are favorable. In this example, the seeds are released in mid-spring when their native habitat is drying out and becoming hot, so dormancy ensures they don't germinate prematurely and are able to wait for more favorable conditions.

Question 4

As a seed undergoes the early stages of germination,its water content will _______ and its water potential will become _______ negative.

Accepted Answer

The answer of As a seed undergoes the early stages...

Question 5

The pre-photosynthetic seedling must survive using resources from the _______ or the _______.

Accepted Answer

The cotyledons are the first leaves to emerge from the seed and provide nutrients for the seedling until it can make its own food through photosynthesis. The endosperm is the tissue within the seed that provides energy and nutrients for the growing embryo.

Question 6

Which step is initially most crucial for the survival of a growing seedling that has germinated an inch underground?

Accepted Answer

Rapid elongation of the shoot is crucial for the seedling to reach the surface and access light, which is necessary for photosynthesis and further growth.

Question 7

Plant primary roots typically grow into the ground by responding to the directional signal of gravity.If you wanted to identify a plant that had a mutation in its gravity signal transduction pathway,which method would be most useful?

Accepted Answer

Mutant plants with altered gravity signal transduction would show root growth in a direction different from the wild-type plants when grown under normal conditions.

Question 8

A scientist receives a seed sample from a plant growing in an unknown location and discovers that prolonged cold treatment is needed to break seed dormancy.This suggests that in the native habitat of the plant,the colder part of the year

Accepted Answer

The need for prolonged cold treatment to break seed dormancy suggests that the plant's native habitat experiences cold conditions right before the optimal growing season, as this adaptation ensures that seeds germinate at the right time for growth.

Question 9

If you were conducting a study to determine how seeds from various habitats break dormancy,which experimental variable would be least useful?

Accepted Answer

Low oxygen levels are generally not a common factor influencing seed dormancy breakage compared to other factors like fire, temperature changes, or soil microorganisms.

Question 10

Which method is most useful for studying plant signal transduction pathways?

Accepted Answer

Genetic screens of mutants are the most useful method for studying plant signal transduction pathways as they allow scientists to isolate and analyze specific components of the pathway and determine their roles in the process.

Question 11

You are given a sample of seeds to analyze and are told that the germination process may have begun.If this is the case,the seeds will

Accepted Answer

If the germination process has begun, it means the seeds have imbibed water and started the process of sprouting.

Question 12

A researcher studying a seedling can determine its stage of development according to the molecular phenomena that are occurring.If DNA synthesis is observed,the seedling is at the stage at which

Accepted Answer

DNA synthesis begins during the stage where the embryonic root, or radicle, begins to grow. This is known as the germination stage. Gibberellins are typically secreted during the seedling emergence stage, which is after germination. Imbibition, endosperm metabolism, and aleurone layer assembly occur during earlier stages of seed development.

Question 13

A scientist is studying seeds from a species of sundew native to Western Australia.These seeds need to be treated with smoke before they can imbibe and germinate.This suggests that _______ in order for the seeds to germinate.

Accepted Answer

The fact that smoke is required for the seeds to imbibe and germinate suggests that there is a seed dormancy mechanism in place that needs to be broken in order for the seeds to germinate.

Question 14

In order to respond to environmental stimuli,plants employ sequences of biochemical reactions called

Accepted Answer

Plants respond to environmental stimuli using signal transduction pathways that involve a series of biochemical reactions which convert the initial stimulus into an appropriate response. This process involves the activation or deactivation of proteins, gene expression, and the production of second messengers.

Question 15

The adaptive advantage of seed dormancy is that it may

Accepted Answer

Seed dormancy provides multiple benefits for plants. It allows them to germinate at a favorable time when environmental conditions are most suitable for growth and survival (A). Dormancy also increases the chances of germinating in the right place by increasing the probability of the seed being transported and deposited in a suitable location (B). Seed dormancy can also help plants avoid competition with other plants for resources like water, nutrients, and light by delaying germination until the conditions are optimal for growth and survival (C). Finally, dormancy can increase the likelihood of dispersal by delaying germination until the seed has been transported to a new location (D). Therefore, all of the above options are beneficial to plants and contribute to the adaptive advantage of seed dormancy.

Question 16

Which sequence represents the correct order of the stages of seed germination and subsequent events?

Accepted Answer

Imbibition is the first stage of seed germination, followed by RNA synthesis, starch degradation, and cell division.

Question 17

What part of the weight of a dormant seed is water?

Accepted Answer

The water content of a dormant seed can range from 5-15 percent, depending on the species. This water is important for seed germination, as it helps to activate enzymes that break down stored nutrients and fuel the growth of the embryo. If a seed becomes too dry or experiences extreme temperatures, this can damage its ability to germinate.

Question 18

A botanist is trying to isolate all of the auxin produced in a bean plant by extracting it from seedlings in a range of developmental stages.Which aspect of plant hormones must the scientist take into consideration while planning the extraction protocol?

Accepted Answer

Plant hormones, including auxins, are produced in many different parts of the plant and are transported throughout the organism to produce various physiological effects. Therefore, the botanist must take into consideration the different developmental stages of the seedlings and sample from different parts of the plants in order to capture the entire range of auxin produced.

Question 19

A biology class studying plant development is observing the germination of orange seeds.What structure are they most likely to observe emerging first from the seed coat?

Accepted Answer

The radicle is the first structure to emerge from the seed coat during germination. It is the embryonic root that will eventually grow into the primary root of the plant.

Question 20

What molecule is most critical for the germination of all seeds?

Accepted Answer

Water is the most critical molecule for the germination of all seeds, as it is required for the activation of enzymes that break down stored food reserves and drive growth processes. Glucose, DNA, and protein are important for plant growth and development, but they are not as immediately necessary for the germination of seeds.

Quiz 26: Plant Growth and Development

In apple plants,cotyledons protect the shoot of the seedling as it grows.Eventually,the plant becomes a small deciduous tree that produces large pomaceous fruits (the apple) .Based on this developmental course,one can infer that