Statement I: | The root apical meristem and the shoot apical meristem are responsible for the primary growth of the plants and cause the increase in the girth of the organs in which they are active. |
Statement II: | In dicotyledonous plants and gymnosperms, the lateral meristems, vascular cambium and cork-cambium principally contribute to the elongation of the plants along their axis. |
I: | Root apical meristem |
II: | Shoot apical meristem |
III: | Vascular cambium |
IV: | Cork-cambium |
1. | Growth is primarily expressed as increase in number of cells at the root apical meristem in maize. |
2. | Growth is primarily represented as increase in size of cells in watermelons. |
3. | Growth of a pollen tube is measured in terms of its girth. |
4. | An increase in surface area denotes the growth in a dorsiventral leaf. |
Assertion (A): | Growth, at the cellular level, is measured by a variety of parameters, some of which are: increase in fresh weight, dry weight, length, area, volume and cell number. |
Reason (R): | Growth, at a cellular level, is principally a consequence of an increase in the amount of protoplasm, and increase in protoplasm is difficult to measure directly. |
1. | Both (A) and (R) are True and (R) correctly explains (A). |
2. | Both (A) and (R) are True but (R) does not correctly explain (A). |
3. | (A) is True; (R) is False. |
4. | (A) is False; (R) is True. |
1. | They are constantly dividing cells. |
2. | They are rich in protoplasm, possess large conspicuous nuclei. |
3. | Their cell walls are primary in nature. |
4. | Plasmodesmatal connections between the cells are absent. |
1. | Increased vacuolation | 2. | Cell enlargement |
3. | Constant division | 4. | New cell wall deposition |
Statement I: | In geometric growth, following mitotic cell division, only one daughter cell continues to divide while the other differentiates and matures. |
Statement II: | In arithmetic growth, both the progeny cells following mitotic cell division retain the ability to divide and continue to do so. |
1. | Lt = L0 + rt | 2. | Lt = L0 X rt |
3. | Lt = L0 / rt | 4. | Lt = L0 - rt |
Assertion (A): | A sigmoid curve is a characteristic of living organism growing in a natural environment. |
Reason (R): | It is typical for all cells, tissues and organs of a plant. |
1. | Both (A) and (R) are True and (R) correctly explains (A). |
2. | Both (A) and (R) are True but (R) does not correctly explain (A). |
3. | (A) is True; (R) is False. |
4. | (A) is False; (R) is True. |