page 13 20. Many species display some characteristics that are typical of r-selection and some that are typical of K-selection. Which of the following species displays only K-selected characteristics? A Leatherback turtles: lay up to nine large clutches of eggs per breeding season; hatchlings receive no parental care; small proportion survives to reach sexual maturity. B Arctic terns: usually lay two eggs per clutch; adults are aggressive in defence of their young; more than 50% of offspring live to 30 years of age. C English oak trees: slow-growing; do not produce seeds until at least 40 years of age; mature trees produce many thousands of seeds annually but only a small proportion germinate. D Common dandelions: readily colonise disturbed ground; grow rapidly; flower several times a year; produce many seeds per flower head. 21. During the ritualised courtship in peafowl, Pavo muticus, the male spreads and shakes his tail feathers to attract a female before stepping back and bowing. This is followed by loud mating calls. This type of fixed action pattern response can be a result of A honest signals B imprinting C male-male rivalry D species-specific sign stimuli. 22. An in vivo study involves observations made in A the natural habitat of an animal B a living cell culture in the laboratory C a living organism D extracts prepared from living tissues. [Turn over