Statement I: | Parenchyma is living but collenchyma is dead tissue. |
Statement II: | Gymnosperms lack xylem vessels but presence of xylem vessels is the characteristic of angiosperms. |
A. | Companion cells help in maintaining the pressure gradient in the sieve tubes. |
B. | Gymnosperms lack vessels in their xylem |
C. | The xylem vessels are devoid of cytoplasm |
D. | Xylem fibres may be septate or aseptate |
E. | A mature sieve element in phloem possesses cytoplasm, vacuole and nucleus. |
Statement I: | In collenchyma, cell walls are thickened at corners due to deposition of cellulose, hemicellulose and pectin. |
Statement II: | Sclerenchyma consists of lignified cell walls and possesses pits. |
Statement I: | Endarch and exarch are the terms often used for describing the position of secondary xylem in the plant body. |
Statement II: | Exarch condition is the most common feature of the root system. |
Assertion (A): | Late wood has fewer xylary elements with narrow vessels. |
Reason (R): | Cambium is less active in winters. |
1. | (A) is False but (R) is True. |
2. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
3. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
4. | (A) is True but (R) is False |
A: | Lenticels are the lens-shaped openings permitting the exchange of gases. |
B: | Bark formed early in the season is called hard bark. |
C: | Bark is a technical term that refers to all tissues exterior to vascular cambium. |
D: | Bark refers to periderm and secondary phloem. |
E: | Phellogen is single- layered in thickness. |
1. | B and C only | 2. | B, C and E only |
3. | A and D only | 4. | A, B and D only |