Sexuality in Plants and Animals.

Sexuality in Plants and Animals.
In Plants.
Bisexual Plants: Plants having both male & female reproductive structures in the same plant.
Unisexual: Plants that possess either male or female reproductive structure only.
In bisexual Plants staminate flowers & pistillate flowers are present.

Staminate flower: Male flower bearing only stamens.

Pistillate flower: Femle flower bearing only pistil.

Diploid and Haploid
Haploid: Having half the number of the diploid condition (n).In this condition a cell or nucleus has a single set of unpaired chromosomes.Chromosome number of human are 23.
eg: Male gamete & Female gamete.
Diploid: Having full number of chromosomes characteristic in species.There are two set of chromosomes,one from each parent(2n). eg:Zygote, In Human the condition 2n are 23 pairs.
Haploid organisms produce gametes by mitotic division.
In diploid species, there are specialised cells called meiocyte or gamete mother cell undergoes meiosis. It results in the formation of haploid gamets. So gametogenesis and meiosis are interlinked.

Chromosome number in meiocytes [diploid (2n) ] & gametes[haploid (2n)] of some organisms.





Gametes possess half the number of chromosomes compared to meiocyte.

Gamete Transfer
In this process the male and female gametes are physically brought together to facilitate fusion between them.
In majority of organisms the male gamete is motile and female gamete is non motile (motile=can move).
In plants fution of gamets is possible through pollination.