Consider the following statements regarding phytochrome:

I. Pr is metabolically inactive and absorbs red light(660nm). On absorption of light it gets

   converted into a metabolically active Pfr.

II. Pfr converts back to Pr after absorbing far red light(730nm).

III. Treatment with red light (R) stimulates seed germination,whereas far red light (FR)

     inhibits seed germination.

   The correct statements are:

(1) I and II

(2) I and III

(3) I, II, III

(4) None

 53%

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

Consider the following statements:

I. They flower when the day length is less than a certain critical length. If these plants are

exposed to day lengths in excess of this critical point, they continue growing vegetatively.

II. Long day plants flower when the day length is greater than a certain critical length

III. short day plants are actually long night plants and long day plants are actually short

     night plants. The correct statements are:

(1) I and II

(2) II and III

(3) I and III

(4) I, II and III

 56%

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

Consider the following statements:

I. The phytochrome-mediated response to photoperiod occurs in the leaves

II. Flowering occurs in the apical meristems.

III. A signal, called florigen, connects the two

The correct statements are:

(1) I, II, III

(2) I, II

(3) I, III

(4) II, III

 71%

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

advertisementadvertisement

Assertion(A): Flowering in certain plants depends on the relative durations of light and dark periods.
Reason(R): Flowering in LDP needs only the duration of light period.
Choices for Assertions and reasons:
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 the correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true.
 68%
From NCERT

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.

Hints

To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.