Topic 3B.4 Gametes: Structure and Function

gametogenesis

the formation of the gametes by meiosis in the sex organs

oocyte

the cell in an ovary which may form an ovum if it undergoes meiotic division

acrosome

the region at the head of the sperm that contains enzymes to break down the protective layers around the ovum

zona pellucida

a layer of protective jelly around the unfertilised ovum

sporophyte generation

the diploid generation in plants that produces spores by meiosis

gametophyte generation

the haploid generation in plants that gives rise to the gametes by mitosis

sporophyte

the diploid main body of the plant

microgametes

the male gametes produced in plants, the pollen grains

tube nucleus

the male nucleus that will control the production of the pollen tube in fertilisation

generative nucleus

the male nucleus that will fuse with the female nucleus

pollen tube

a tube that grows out of a pollen grain down the style, into the ovary and through the micropyle of the ovule to carry the generative nucleus (which divides to form two male nuclei) to the ovule

placenta (plant)

the pad of special tissue that attaches the plant ovule to the ovary wall

megagamete

the female gamete, the egg cell, in plants