Factors Affecting Plant Development

Q. Plant growth regulators can be categorized under ______________.

1. intercellular intrinsic factors
2. intracellular intrinsic factors
3. extrinsic factors
4. none of these

Q. The term synergistic action of hormones is ______.

1. When one hormone affects more than one function

2. When many hormones bring about any one function

3. When two hormones act together but bring about opposite effects

4. When two hormones act together and contribute to the same function

Q. Genetic factors are factors whereas environmental factors are factors affecting plant growth and development.

1. plastic
2. intrinsic
3. extrinsic
4. flexible

Q. Read the assertion and reason carefully to mark the correct option in question.

Assertion: Growth, differentiation and development are very closely related events in the life of a plant.

Reason: Development in plants (i.e., both growth and differentiation) is under the control of intrinsic and extrinsic factors.

1. If both assertion and reason are true but reason is not the correct explanation of the assertion.
2. If both assertion and reason are false.
3. If both assertion and reason are true and the reason is the correct explanation of the assertion.
4. If the assertion is true but the reason is false.

Q. Plant hormone which is translocated to other parts for the growth of the plant is:

1. IAA
2. Gibberellins
3. Cytokinins
4. Zeatin

Q.

In animals, there are special glands secreting hormones, whereas there are no glands in plants. Where are plant hormones formed? How are the hormones translocated to the site of activity?

Q. What is chemotropism ? Give one example. Name any two plant hormones and mention their functions.

Q.

How is development defined in terms of differentiation and growth?

Q.

While experimentation, why do you think it is difficult to assign any effect seen to any single hormone?

Q. Which is not a phytohormone?

1. Phytochrome
2. GA
3. Florigen
4. IAA

Q. In tissue culture, callus can be induced to form shoot or root by altering the ratio of

1. Cytokinin to ethylene
2. Auxin to cytokinin
3. Auxin to gibberellin
4. Gibberellin to cytokinin

Q.

Look at the image below. The circled parts are the site of action for certain PGRs. Identify the PGR that would affect the site and choose the correct option.

1. a- Gibberellins, b- Abscisic Acid, c- Ethylene, d- Auxins

2. a- Abscisic Acid, b- Auxins, c- Gibberellins, d- Ethylene

3. a- Auxins, b- Ethylene, c- Gibberellins, d- Abscisic Acid

4. a- Ethylene, b- Gibberellins, c- Abscisic Acid, d- Auxin

Q. In plants, the type of germination in which the cotyledons remain underground is

1. epigeal germination
2. hypogeal germination
3. indefinite type
4. definite

Q. Assertion :Development is the sum of growth and differentiation. Reason: Development in plants is under the control of extrinstic factors only.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Callus develops roots if medium is supplied with

1. Auxin
2. Both cytokinin and auxin
3. Cytokinii
4. More cytokinin and less auxin

Q. The natural plant hormones were first isolated from

1. Cotton fruits, spinach leaves and rice plant
2. Human urine and corn germ oil
3. Avena coleoptiles, spinach leaves and fungus Gibberella
4. Human urine and rice plant

Q. In plant tissue culture, induction of roots and shoots can be accomplished by _______________.

1. Using tissue of a certain minimum size
2. Using a specific concentration of sucrose in the culture medium
3. Using a particular auxin-cytokinin ratio
4. Manipulating physical factors such as duration of light, temperature, pH etc.

Q. Abscission of fruits is prevented by

1. ABA
2. Ethylene
3. Cytokinin
4. IBA

Q. Choose the correct statement about auxins:

1. Auxins are responsible for inhibition of apical dominance
2. Indole-3-acetic acid, Naphthalene acetic acid and kinetin are the examples of auxins
3. Auxins promote fruit and leaf drop at early stages
4. Auxins promote flowering e.g., in pineapples

Q.

what is the role of auxin in gravotropism

Q.

Look at the image below. The circled parts are the site of action for certain PGRs. Identify the PGR that would affect the site and choose the correct option.

1. a - Gibberellin, b - Abscisic Acid, c - Ethylene, d - Auxin

2. a - Abscisic Acid, b - Auxin, c- Gibberellin, d - Ethylene
3. a - Auxin, b - Ethylene, c - Gibberellin, d - Abscisic Acid
4. a - Ethylene, b - Gibberellin, c - Abscisic Acid, d - Auxin

Q. The concept of cellular totipotehcy was given by

1. Steward
2. Carlson et al
3. Vasil and Hilderbrandt
4. Barski et al

Q. Which one of the following generally act as an antagonist to gibberellins?

1. Zeatin
2. Ethylene
3. ABA
4. IAA