Role of Gibberellin

Q.

During seed germination, its stored food is mobilized by

1. gibberellin

2. ABA

3. cytokinin

4. ethylene

Q.

What is bolting? What condition can induce it naturally and how it can be induced artificially?

Q.

What is the precursor of the plant hormone gibberellin?

Q.

Bolting is promoted by:

1. CK

2. Gibberellins

3. NAA

4. Zeatin

Q. In order to increase the yield of sugarcane crop, which of the following plant growth regulators should be sprayed?

1. Auxins
2. Gibberellins
3. Cytokinins
4. Ethylene

Q.

Why dont boiled seeds germinate?

Q. In 1920s, the Japanese biologist Kurosawa and his colleagues discovered the foolish-seedling disease' in which rice plants grow too tall, is caused by

1. a gibberellin secreting fungi
2. the herbicide 2, 4-D
3. degraded nucleic acids
4. too much auxin, due to stagnant water in the fields

Q. Match the following:

Column I	Column II
a. Weedicide	(i) GA${}_3$
b. Bolting	(ii) Cytokinin
c. Thinning of cotton	(iii) Ethylene
d. Lateral shoot growth	(iv) 2, 4-D

1. a(iii), b(ii), c(iv), d(i)
2. a(iv), b(i), c(iii), d(ii)
3. a(iv), b(i), c(ii), d(iii)
4. a(iv), b(ii), c(iii), d(i)

Q. ___________ hormone breaks the dormancy of a potato tuber.

1. Cytokinin
2. Abscisic Acid
3. Auxin
4. Gibberellin

Q.

Root development is promoted by

1. Abscisic acid

2. Auxin

3. Gibberellin

4. Ethylene

Q. A plant growth hormone promotes bolting in beet. Which among the following is not an effect of this hormone?

1. Elongation of stem
2. Mobilization of food reserves
3. Fruit development
4. Ripening of fruits

Q.

Why do germinating seeds have high amylase activity?

Q.

Give an example of a plant hormone that promotes growth.

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

Assertion: Ethylene helps the plants to increase their absorption surface.

Reason: Ethylene promotes root growth and root hair formation.

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

Q.

What are auxin and cytokinin?

Q.

Define germination. What are the conditions required for germination of seed?

Q. Which of the following hormones does not promote abscission?

1. Auxin
2. Gibberellic acid
3. Ethylene
4. Abscisic acid

Q. PGRs that involve in growth inhibiting activities are

1. Abscisic acid and auxins

2. Ethylene and Gibberellins

3. Cytokinin and ABA

4. ABA and ethylene

Q. Auxin was isolated from tips of coleoptiles of

Q. Internodal elongation in sugarcane stem is promoted by:

1. ABA
2. Cytokinin
3. Auxin
4. $G{A}_3$

Q. Match the following:

Column I	Column II
a. Ethephon	(i) GA
b. Terpene	(ii) Ethylene
c. Zeatin	(iii) Natural auxin
d. IAA	(iv) Cytokinin

1. a(ii), b(i), c(iii), d(iv)
2. a(ii), b(i), c(iv), d(iii)
3. a(iv), b(ii), c(iii), d(iv)
4. a(i), b(ii), c(iii), d(iv)

Q.

Question 16

Gibberellins were first discovered in Japan when rice plants were suffering from bakane (the foolish seedling disease) caused by a fungus Gibberella fujikuroi.
Give two functions of this phytohormone.

Which property of gibberellin caused foolish seedling disease in rice?

Q. Assertion : Plants having gene from Bacillus thuringiensis are resistant to insects .

Reason : These transgenic plants have receptors which convert protoxin into active toxin.

1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is not correct explanation of A
3. A and R are false
4. A is true but R is false

Q.

Genetic dwarfness in some plants may be solved by treatment with:

1. Auxins

2. Gibberellins

3. Antigibberellins

4. Ethylene

Q.

What is the difference between auxin and cytokinin?

Q.

What stimulates plant growth?

Q. Which hormone promotes bolting?

1. Gibberellin
2. Cytokinin
3. 2, 4-D
4. Zeatin

Q. Gibberellin promotes _______________

1. germination of seed
2. dormancy of seed
3. senescence
4. elongation of root

Q. Gibberellin helps in _____________

1. Elongation of internodes
2. Curving of coleoptile towards the light
3. Initiation of lateral roots
4. Cell division

Q.

Differentiate between the following:
Auxins and ethylene