Ontogenesis – individual development
Answers are for parents and teachers.
1
Describe the three types of ontogenesis (larval, in an egg, in the mother’s body) and name two animals for each.
Larval – frog, butterfly; in an egg – swallow, snake; in the mother’s body – cow, human.
2
Give two examples of animals that develop with complete metamorphosis and write its importance in nature.
Butterfly and honeybee. The larva feeds and grows, the pupa reorganises the body, the adult reproduces and disperses; the different stages reduce competition.
3
Give three examples of biorhythms (daily and seasonal).
Daily: sleep and waking, variation in body temperature; seasonal: leaf fall in autumn, moulting and hibernation of animals.
4
How many blastomeres are there after 7 cleavage divisions? (Number only.)
128
5
Why are regeneration and immunity important in maintaining homeostasis?
Regeneration restores damaged or worn cells and tissues; immunity neutralises foreign substances and microbes; both keep the internal environment constant.