Question

Describe components of phloem. Define translocation.

Answer 1

• Phloem is complex permanent tissue. It conducts organic solutes or food materials from leaves to different parts of plants.
  
• Phloem is composed of the following four components or cells.

1. Sieve tubes – Sieve tubes are slender, tube-like structures composed of elongated thin-walled cells, placed end to end. Their end walls are perforated by numerous pores called sieve plates.

2. Companion cells - These cells are found associated with sieve tubes and connected. These are thin-walled cell containing dense and very active cytoplasm and large elongated nucleus.

3. Phloem parenchyma - These cells are living and thin walled.

4. Phloem fibres - They have thick walled, elongated, dead cells.

Translocation: The bulk movement of substances through the conducting vascular tissues of plants is called translocation.