Tag: plants: structure and function

Questions Related to plants: structure and function

Choose the correct answers from the alternatives given.
The structure that forms most of the flesh of an apple is the

biology fruit and seed morphology of the fruit fruit plants: structure and function

  1. pistil

  2. receptacle

  3. petal

  4. stamen

Show answer
Correct Option: B
Explanation:
An Apple is called a false fruit as it is developed from the thalamus, not from the ovary. Thus apple flesh is not derived from the ovary instead it is derived from the receptacle.
So, the correct answer is receptacle.


Which one of the following is produced during stress conditions which leads to closure of stomata?

biology chemical coordination in plants abscisic acid fruit plants: structure and function

  1. Auxin

  2. ABA

  3. Cytokinin

  4. Gibberellin

Show answer
Correct Option: B
Explanation:

Abscisic acid is a phytohormone critical for plant growth and development and plays an important role in integrating various stress signals and controlling downstream stress responses. Plants have to adjust ABA levels constantly in response to changing physiological and environmental conditions. ABA causes the closure of stomata. It thus helps in reducing the rate of transpiration.

Which one of the following acids is a derivative of carotenoids?

biology chemical coordination in plants abscisic acid fruit plants: structure and function

  1. Gibberellic acid

  2. Abscisic acid

  3. Indole butyric acid

  4. Indole-3-acetic acid

Show answer
Correct Option: B
Explanation:

Abscisic acid is also called as abscism. It is a plant hormone which has carotenoid as precursor. ABA functions in many plant developmental processes, including bud dormancy. ABA is an isoprenoid plant hormone, which is synthesized in the plastidal 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway, unlike the structurally related sesquiterpenes, which are formed from the mevalonic acid-derived precursor farnesyl diphosphate, the C15 backbone of ABA is formed after cleavage of C40 carotenoids in MEP.

Which one is anti transpirant hormones?

biology chemical coordination in plants abscisic acid fruit plants: structure and function

  1. Auxin

  2. Cytokinin

  3. Abscisic Acid

  4. Gibberellin

Show answer
Correct Option: C
Explanation:

Abscisic acid is anti-transpirant hormone. It stimulates the closure of stomata in the epidermis and increases the tolerance of plants to various kind of stresses. It is also called stress hormone.

A substance that induces dormancy in seed is

biology plants: structure and function abscisic acid fruit chemical coordination in plants

  1. ABA

  2. GA

  3. Thiourea

  4. Cytokinins

Show answer
Correct Option: A
Explanation:

A substance that induces dormancy in seed is ABA. Abscisic acid (ABA), also known as abscisin II and dormin, is an isoprenoid plant hormone. ABA functions in many plant developmental processes, including bud dormancy. It is responsible for seed dormancy by inhibiting cell growth inhibits seed germination.

Thus, the correct answer is option A.

The hormone produced during adverse environment condition is ...............

biology chemical coordination in plants abscisic acid fruit plants: structure and function

  1. Abscisic acid

  2. $N^{6}$ - Isopentanyl adenine (CK)

  3. Dichlorophenoxy acetic acid, (2, 4 - D)

  4. Gibberellic acid (GA)

Show answer
Correct Option: A
Explanation:

Abscisic acid (ABA) was discovered for its role in regulating abscission and dormancy. But like other PGRs, it also has other wide ranging effects on plant growth and development. It acts as a general plant growth inhibitor and an inhibitor of plant metabolism. ABA inhibits seed germination. ABA stimulates the closure of stomata in the epidermis and increases the tolerance of plants to various kinds of stresses.Therefore, it is also called the stress hormone. ABA plays an important role in seed development, maturation and dormancy. By inducing dormancy, ABA helps seeds to withstand desiccation and other factors unfavourable for growth. In most situations, ABA acts as an antagonist to gibberellins.

Which of the following is a stress hormone?

biology chemical coordination in plants abscisic acid fruit plants: structure and function

  1. Benzyl aminopurine

  2. Dichlorophenoxy acetic acid

  3. Ethylene

  4. Abscisic acid

Show answer
Correct Option: D
Explanation:

Despite its name, abscisic acid does not induce abscission in most plants. Instead, abscisic acid is involved in a plants response to stress and in seed dormancy, a temporary state of arrested physiological activity. As an environmental stress hormone, abscisic acid particularly promotes changes in plant tissues that are water stressed.

Thus, the correct answer is option D.

Abscisic acid induces .......................

biology chemical coordination in plants abscisic acid fruit plants: structure and function

  1. Shoot elongation

  2. Cell elongation and cell wall formation

  3. Cell division

  4. Leaf fall and dormancy

Show answer
Correct Option: D
Explanation:
Abscisic acid (ABA) was discovered for its role in regulating (leaf and fruit) abscission and dormancy. But like other PGRs, it also has other wide ranging effects on plant growth and development. It acts as a general plant growth inhibitor and an inhibitor of plant metabolism. ABA inhibits seed germination. ABA stimulates the closure of stomata in the epidermis and increases the tolerance of plants to various kinds of stresses. Therefore, it is also called the stress hormone. ABA plays an important role in seed development, maturation and dormancy. By inducing dormancy, ABA helps seeds to withstand desiccation and other factors unfavourable for growth. In most situations, ABA acts as an antagonist to gibberellins
So, the correct answer is 'Leaf fall and dormancy'

In autumn leaf fall occurs, because

biology chemical coordination in plants abscisic acid fruit plants: structure and function

  1. Formation of abscission layer at the base.

  2. Leaf becomes heavy.

  3. Leaf does not remain green.

  4. Of low temperature.

Show answer
Correct Option: A
Explanation:

Deciduous plants shed leaves in autumn. The shedding of leaves is a controlled and orderly process preceded by the formation of abscission layer at the base of leaf or fruit.

Thus, the correct answer is option A.

Hormone produced during leaf fall is

biology chemical coordination in plants abscisic acid fruit plants: structure and function

  1. IAA

  2. ABA

  3. Florigen

  4. Kinetin

Show answer
Correct Option: B
Explanation:

Abscisic acid (ABA) was discovered for its role in regulating abscission and dormancy. It is the hormone believed to be responsible for controlled abscission of mature leaves and fruits from plants. But like other PGRs, it also has other wide ranging effects on plant growth and development. It acts as a general plant growth inhibitor and an inhibitor of plant metabolism. ABA inhibits seed germination. ABA stimulates the closure of stomata in the epidermis and increases the tolerance of plants to various kinds of stresses. Therefore, it is also called as the stress hormone.

Thus, the correct answer is option B.