Question

What are cytoplasmic strands? Why do they pass through the holes of sieve plates?

Answer 1

Cytoplasmic strands are otherwise called as plasmodesmata. These are small extensions of cytoplasm which extend through cell wall of plant cells to connect adjoining cells. Cytoplasmic strands also hold nucleus in position inside the cell. These can transport transcripts, proteins and signals from the nucleus to the periphery of the cell. Cytoplasmic strands pass into sieve plates in the early stages of development. Sieve plates are the connection sites of the sieve elements. Sieve elements, being a type of phloem cells, aid in transport of food molecules among the cells.