Sexual Reproduction in Plants

[Bernard NebelKeymaster]

PLANTS.  As biologists investigated the life cycles of plants on a cellular level, they discovered the same phenomena of meiosis, to occur; that is the same process of segregation and recombination of chromosomes. 

Typically, the same plant is both male and female, That is flowers have both male and female parts as describe in the following video. 

Meiosis occurs within the anthers and resulting  cells with a single (1N) set off chromosomes. These develop into pollen grains. Meiosis also occurs within ovules giving rise to  1N egg cells. Pollen grains landing on the sigma germinate, grow their way down to the ovule, and deliver the sperm nucleus to the egg. A fertilized egg grows into the plant embryo while the tissue surrounding ovule develops into

into the rest of the seed. 

There are variations regarding the sexual nature of plants. 

1. Many species have both sexes within the same plants/flowers as described above
2. In other species, there are separate male (anthers only) and female (carpels only) flowers on the same plant
3. In other species sexes are separate. Members may be male (have only anther bearing flowers) or female (have only carpel bearing flowers.)
4. There are many nonflowering plants, e.g., cone bearing trees, mosses, ferns. The have structures analogous to flowers. Meiosis and fertilization as a key part of their life cycles.

Discuss: What is the significance of meiosis and fertilization. Every organism examined (animal, plant, fungus etc) is found to have it as part of its life cycle. Must it not have a very significant biological purpose?

[Author]

Posts