Theory question 103
Ecological Associations(a) What is meant by competition
(b) Explain briefly the terms (i) inter-species competition (ii) intra-species competition
(c) Explain two ways each by which the toad/frog is structurally adapted to the following: (i) obtaining food; (ii) protection; (iii) movement.
Show the model answer
(a) Competition is the struggle between organisms for resources that are in limited supply (food, water, light, space, mates)
(b)(i) Inter-species competition: between members of different species for the same resource, e.g. goats and cattle for grass
(ii) Intra-species competition: between members of the same species, e.g. maize plants in an overcrowded farm for light and nutrients; usually more severe because their needs are identical
(c)(i) Food: long sticky tongue attached at the front of the mouth, flicked out to catch insects; wide mouth; protruding eyes for spotting prey; small teeth on upper jaw to grip prey
(ii) Protection: colour of skin matches surroundings (camouflage); skin glands secrete poisonous/distasteful substances (toad's parotid glands); eyes on top of the head see danger while body is under water; slimy skin
(iii) Movement: long, strong hind limbs for jumping; webbed hind feet for swimming; short fore limbs absorb landing shock; streamlined body
Give two separate structures for each of the three headings.