Statement I: | In roots, the protoxylem lies towards the center (pith) and the metaxylem lies towards the periphery of the organ. This type of primary xylem is called endarch. |
Statement II: | In stems, the protoxylem lies towards the periphery and the metaxylem lies towards the center. Such an arrangement of the primary xylem is called an exarch. |
Assertion (A): | Xylem and phloem are not called complex tissues in a plant body. |
Reason (R): | They are composed of a single type of cell with similar structures and functions. |
1. | Both (A) and (R) are True and (R) correctly explains (A). |
2. | Both (A) and (R) are True and (R) does not correctly explain (A). |
3. | (A) is True; (R) is False |
4. | Both (A) and (R) are False |
Assertion (A): | Vessels are particularly advantageous in environments where rapid water transport is needed, such as in tall trees or in plants growing in warm, sunny environments. |
Reason (R): | Tracheids are less efficient in conducting water due to their smaller diameter and the absence of large openings (perforations) at their ends. |
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 |
I: | Sclerenchyma cells are typically dead and have thickened lignified walls that help in providing structural support. |
II: | Xylem tissues are primarily involved in the storage of proteins and starch. |
III: | Phloem tissues are responsible for the transport of water and minerals from the roots to the leaves. |
IV: | Parenchyma cells are versatile cells that can store food, and are also involved in photosynthesis and repair. |
Statement I: | Gymnosperms lack albuminous cells and sieve cells. |
Statement II: | Gymnosperms have sieve tubes and companion cells. |
I: | Monocots have companion cells, dicots do not. |
II: | Monocots have sieve tubes, while dicots have sieve cells. |
A | B | |
1. | Xylem | Phloem |
2. | Phloem | Xylem |
3. | Vessel | Tracheid |
4. | Tracheid | Vessel |
I: | Gymnosperms have albuminous cells and sieve cells but lack sieve tubes and companion cells |
II: | The sieve tube elements and companion cells are connected by pit fields present between their common longitudinal walls. |
III: | Cell walls of phloem parenchyma cells have pits through which plasmodesmatal connections exist between cells. |
IV: | Phloem parenchyma is absent in most of the monocots. |
V: | Phloem fibers become dead at maturity. |
VI: | Phloem fibers are generally absent in primary phloem. |