Question

Explain the phenomenon of alteration of generation.​

Answer 1

AnsWer :

• The life cycle of a plant includes two generations, sporophytic (diploid = 2n) and gametophytic (haploid = n)

• Some special diploid cells of sporophyte divide by meiosis to produce haploid cells.

• These haploid cells divide mitotically to produce gametophyte.

• On maturation, gametophyte produces gametes which fuse during fertilization and produce diploid zygote.

• Diploid zygote divides by mitosis and forms diploid sporophyte.

• Thus, sporophytic and gametophytic generations generally occur alternately in the life cycle of a plant.

• Bryophytes and Pteridophytes show distinct alternation of generation.