Alternation of Generations Plant Reproduction Alternation of Generations

Alternation of Generations – the way in which all land plants and many algae undergo sexual reproduction

First, let’s talk about animals…

Plants are similar New plants are formed by the union of sex cells Each sex cell carries half the hereditary material to create a new plant But, plants can carry both male and female sex cell structures

Plant life cycle 2 distinct stages, or “generations”, of plants Adult generation produces spores, and is a sporophyte Immature “spore” generation are called gametophytes. These produce sex cells, called gametes

Soooooo………. Plant Life Cycle Sporophyte chromosomes exist in its cells in pairs – denoted as “2n” Full set of chromosomes in a cell is also referred to as being diploid Gametophyte chromosomes exist in its cells as singles – denoted as “1n” Half set of chromosomes = haploid Soooooo……….

And the cycle begins again… Plant Life Cycle Most of a plant’s life cycle is spent with a full set of chromosomes (as a sporophyte) However, plants live one entire stage, or “generation”, of life with a single set of chromosomes (as a gametophyte) When the sex cells, or gametes, produced by gametophytes come together, fertilization occurs And the cycle begins again…