Topic 3B.5 Fertilisation in Mammals and Plants

pollination

the transfer of pollen from the anther to the stigma, often from one flower to another

external fertilisation

the process of fertilisation in which the female and male gametes are released outside of the parental bodies to meet and fuse in the environment

internal fertilisation

the fertilisation of the female gamete by the male gamete, which takes place inside the body of the female

mating

the process by which a male animal transfers sperm from his body directly into the body of the female

acrosome reaction

the reaction seen when the sperm reach the oocyte and enzymes are released from the acrosome and digest the follicle cells and the zona pellucida

polyspermy

the fertilisation of an egg by more than one sperm

cortical reaction

the reaction seen when cortical granules in the cytoplasm of the ovum release enzymes into the zona pellucida; these enzymes destroy the sperm-binding sites and also thicken and harden the jelly of the zona pellucida

fertilisation membrane

the tough layer that forms around the fertilised ovum to prevent the entry of other sperm

conception

the term used for fertilisation of the ovum in humans

germinate

(of pollen) the process by which a pollen tube starts to grow out of the pollen grain to transfer the male nuclei to the ovule

double fertilisation

the process that occurs in plants in which one male nucleus fuses with two polar nuclei to form the triploid endosperm nucleus and the other fuses with the egg cell to form the diploid zygote