Question

Which of the following does not lose its nucleus at maturity?

• A. Companion cells
• B. Red blood cells
• C. Vessel
• D. Sieve tube cells

Answer 1

The correct option is A

Companion cells

The correct option is A.

Explanation of the correct option:

1. The nucleus is an important membrane-bound organelle found in eukaryotic cells.
2. They carry all the genetic information of the cell. All cells do not have a nucleus.
3. Companion cells contain a nucleus and have a large number of mitochondria and ribosomes.
4. Option a is correct because the companion cell has nucellus even at maturity.

Explanation of the incorrect options:

Option B:

Red blood cells in humans do not have nuclei at maturity.

Option C:

Vessels in plants contain xylem and phloem. Sieve tube cells in plants' phloem do not have nuclei at maturity.

Option D:

Sieve tube cells have cytoplasm in the periphery and have vacuoles but cells lack a nucleus at maturity.

Final answer: Companion cells in plants do not lose nuclei at maturity.