Select true statement -
(A) The presence of vessels in xylem is a characteristics feature of angiosperms
(B) The cells of parenchyma are generally isodiametric
(C) Xylem vessels are multicellular whereas tracheids are unicellular

Options

A. Only A
B. Only B and C
C. Only B
D. All A, B and C

Answer

To solve the question, we need to evaluate each of the statements provided and determine which ones are true.

### Step-by-Step Solution:

1. **Evaluate Statement (A)**: "The presence of vessels in xylem is a characteristic feature of angiosperms."
- **Analysis**: Xylem vessels are indeed a defining feature of angiosperms (flowering plants). They are responsible for efficient water transport and are typically absent in gymnosperms (non-flowering plants). Therefore, this statement is **true**.

2. **Evaluate Statement (B)**: "The cells of parenchyma are generally isodiametric."
- **Analysis**: Parenchyma cells are known to be versatile and can be polygonal, round, or oval in shape. While they can be isodiametric (having equal diameters), they are not exclusively so. Thus, this statement is **partially true** but not universally applicable, leading us to conclude it is **not entirely true**.

3. **Evaluate Statement (C)**: "Xylem vessels are multicellular whereas tracheids are unicellular."
- **Analysis**: Xylem vessels are indeed multicellular structures composed of multiple cells that form long tubes for water transport. In contrast, tracheids are elongated, single cells that are also part of the xylem but are unicellular. Therefore, this statement is **false** as it incorrectly categorizes tracheids as unicellular when they are also part of the xylem.

### Conclusion:
Based on the evaluations:
- Statement (A) is **true**.
- Statement (B) is **not entirely true**.
- Statement (C) is **false**.

Thus, the only true statement is **(A)**.