Grazers and Mutualists

Question 1

Define predation?

Answer 1

Predation is the consumption of all or part of one organism (the prey) by another (the predator) in which the prey is alive when the predator first attacks it.

Question 2

What are true predators?

Answer 2

True Predators kill the prey immediately and kill several over the course of their lifetime.

Question 3

Define Grazers?

Answer 3

Grazers also attack large numbers of prey but remove only part of each prey individual.

Question 4

Give examples of true predators?

Answer 4

Birds of prey, carnivorous plants, whales, large carnivores.

Question 5

Give examples of grazers?

Answer 5

Large ungulates, rodents, marsupials, insect larvae.

Question 6

How do plants avoid grazing?

Answer 6

Physical defences (throws, spines), chemical defences (taste, digestibility, toxicity)

Question 7

How do plants tolerate grazing?

Answer 7

Protection of meristems, alteration of relative rates of growth, utilisation of stored carbohydrates, stimulation of dormant buds.

Question 8

How do grazers affect plant communities?

Answer 8

Affects plant community composition as it alters the competitive balance between the dominant and the subordinate species.

Question 9

Define mutualism?

Answer 9

An association between a pair of species which benefits both.

Question 10

List the order and function of the ruminant digestive system?

Answer 10

Esophagus, food mixed with cellulose fermenting microorganisms in the rumen, passes to the omasum where is is concentrated by water reabsorption, enters abomasum (true stomach) which secretes HCl and proteases, kills microorganisms, food is digested then passed onto the small intestine for further digestion/absorption.

Question 11

Give examples of other mutualistic relationships?

Answer 11

Termites and leaves, mycorrhizae, nitrogen fixation.