Tag Archives | Ontogeny and Phylogeny

Phloem consists of sieve cell, sieve tube, companion cell, phloem parenchyma and fibre. 1. Sieve Cell-Origin: The mother cells of sieve cells vary in shape. They are slender, short cylindrical to elongate with both ends tapering. Numerous primary pit fields occur on lateral walls. During differentiation the mother cells elongate. Vacuole appears in the cytoplasm that streams actively. The cell [...]