Types of Phloem
- Primary Phloem: A vascular plant's primary meristem produces this kind of phloem. Primary phloem is phloem that comes from the procambium during primary growth. The constituents of the main phloem are protophloem or metaphloem.
- Secondary Phloem: In vascular plants, the secondary meristems are where the secondary phloem is produced. This expansion is a result of the vascular cambium, a meristematic tissue. During secondary growth, the vascular cambium gives rise to the secondary phloem. Secondary growth is what causes the increase in plant width, which is mostly seen in trees.
Function of Phloem
- A large amount of the carbohydrates created during photosynthesis are present in water-based sap. Phloem transports these sugars to non-photosynthetic plant parts like the roots or storage organs like tubers or bulbs. Unlike the largely dead xylem, which transfers sap, the phloem is made up of still-living cells.
- Phloem is a group of intricate permanent tissues that grows into the plant's conductive or vascular system. It moves the ready nutrients from the leaves to the storage organs and growth zones. Phloem sap from vascular plants is thought to aid in the communication of instructive impulses.
Which of the following are dead cells in phloem? (a) Sieve Cells (b) Sieve Tubes (c) Companion cells (d) Phloem Fibres
Dead cells in phloem are referred to as fibres. Companion cells, sieve cells, sieve tubes, phloem fibres, and phloem parenchyma are the five cells that make up pholem.