Theory question 104
Behaviour(a) (i) Explain the term courtship behaviour in animals (ii) How does courtship aid reproduction in animals
(b) Describe the process of fertilization in flowering plants
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(a)(i) Courtship behaviour: the series of instinctive actions (display, songs, dances, colour changes, territorial defence, pairing) by which male and female of a species attract each other before mating
(ii) Brings the sexes of the same species together; identifies a suitable mate; makes partners ready to mate at the same time (synchronises release of gametes); reduces aggression; increases the chance of fertilisation
(b) Pollen lands on a ripe stigma (pollination); it absorbs sugary fluid and grows a pollen tube down the style; the tube nucleus leads, and the generative nucleus divides into two male nuclei; the tube enters the ovule through the micropyle and bursts; one male nucleus fuses with the egg cell to form the zygote; the other fuses with the polar nuclei to form the endosperm nucleus (double fertilisation)
After fertilisation: zygote → embryo, ovule → seed, ovary → fruit
Describe the pollen tube's journey before the two fusions.