Question

Vessels and companion cells are found in

• A. angiosperms
• B. pteridophytes
• C. bryophytes
• D. thallophytes.

Answer 1

The Correct Option is A

Vessels are a part of xylem. They are long cylindrical tube-like structures made up of many cells called vessel members, each with lignified walls and a large central cavity devoid of protoplasm (a characteristic feature of angiosperm). In some members of pteridophytes e.g. Selaginella and Equisetum, the primitive vessels are present. Companion cells are part of phloem. They are specialised parenchymatous cells, which are closely associated with sieve tube elements. They help in maintaining the pressure gradient in the sieve tubes. They are absent in pteridophytes and gymnosperms. Thallophytes and bryophytes do not contain vascular bundles (i.e. xylem and phloem).