Question

Which of the following is not an element of phloem tissue?

• A. Tracheids
• B. Sieve tubes
• C. Phloem fibers
• D. Companion cells

Answer 1

The correct option is A

Tracheids

The correct option is A.

Explanation for correct option:

1. Phloem and xylem are the complex tissue found in all vascular plants.
2. Xylem works to transport water and minerals to all the parts of the plants.
3. The main function of phloem is to transport food products from the source to the sink.
4. Tracheids are the part of xylem tissue, which are tubular, long with tapering, chisel-like ends.
5. They help to support and provide upward transportation of water and minerals in all the vascular plants.

Explanation for incorrect options:

Option B:

1. A living tissue found in vascular plants, which mediates the soluble organic components produced at the time of photosynthesis downwards from the leaves is phloem.
2. Sieve tubes are one of the elements of phloem tissues.
3. These are elongated living cells, which help in the transportation of carbohydrates, that is, sucrose from leaves to roots and fruits.

Option C:

1. Phloem fibers are also the constituent of phloem tissues.
2. They are commercially useful as they exhibit great tensile strength and pliability.

Option D:

1. Companion cells are also the elements of phloem tissues.
2. They check the activity of the surrounding sieve elements and take part in unloading and loading the sugar into the sieve element.

Final answer: Tracheids are not the element of phloem tissue.