Which one of the following growth regulators is known as stress hormone?
abscsic acid
Ethylene
GA3
GA3
A.
abscsic acid
Abscisic Acid (ABA) is also known as stress hormone or dormin because it is produced in much higher amounts, when plants are subjected to various kinds of stresses. It often gives plants organs a signal that they are undergoing physiological stresses such as lack of water, saline soil, cold temperature and frost. ABA often cause responses that help plants and protect against these stresses.
Match the following and select the correct answer.
|
Column I |
Column II |
||
|
A. |
Centriole |
1. |
Infolding in mitochondria |
|
B. |
Chlorophyll |
2. |
Thylakoids |
|
C. |
Cristae |
3. |
Nucleic acid |
|
D. |
Ribozymes |
4. |
Basal body cilia of flagella |
|
A |
B |
C |
D |
|
4 |
3 |
1 |
2 |
|
A |
B |
C |
D |
|
1 |
2 |
4 |
3 |
|
A |
B |
C |
D |
|
1 |
3 |
2 |
4 |
|
A |
B |
C |
D |
|
1 |
3 |
2 |
4 |
A few normal seedlings of tomato were kept in a dark room. After a few days they were found to have become white - coloured like albinos. Which of the following terms will you use to describe them?
Mutated
Embolised
Etiolated
Etiolated
Through their effect on plant growth regulators, what do the temperature and light control in the plants?
Apical dominance
Flowering
Closure of stomata
Closure of stomata
Which one of the following generally acts as an antagonist to gibberellins?
Zeatin
Ethylene
ABA
ABA
What causes a green plant exposed to the light on only one side, to bend toward the source of light as it grows?
Green plants need light to perform photosynthesis.
Green plants seek light because they are phototropic
Light stimulates plant cells on the lighted side to grow faster
Light stimulates plant cells on the lighted side to grow faster
