Alternation of genes in plants question.?

Question

I know in the alternation of genes the diploid/sporophyte (2N) and haploid/gametophyte (N) phases switch, as do meosis and mitosis.

But is diploid/sporophyte (2N) meosis or meosis? And same with the other.

Or are the alternations independent?

Answer 1

You are referring to alternation of generations in the plant life cycle.  There is a diploid (2n) sporophyte that produces haploid spores by meiosis.  Sporophytes are the typical plant you see when you are looking at plants.  The spores germinate to form haploid (n) gametophytes that form s*x cells by mitosis.  In the flowering plants, the male gametophyte is the pollen grain and the female is the ovule located in the ovary inside the carpels of the flower.

A cell has to be diploid (2n) to undergo meiosis during which the number of chromosomes is reduced from two complete sets to one set per cell.  Diploid or haploid cells can undergo mitosis.