part 5

Question 1

predation and its examples

Answer 1

predator kills the prey so one of them is benefitted and the other in harmed
eg., ladybird are useful to control aphid and dragonflies for mosquitoes

Question 2

prey species have evolved various mechanisms to reduce the impact of predation. Give two examples

Answer 2

1. certain insect species and frogs have camouflage (cryptical coloration)
2. monarch butterfly is very distasteful to its predator(bird). they have special chemicals. this chemical is produced during its caterpillar stage by feeding on poisonous weed

Question 3

for plants what are the predators and what are known as phytophagous

Answer 3

for plants, herbivores are the predators. nearly all 25% of insects are known as phytophagous

Question 4

even plants have evolved certain mechanisms against herbivores. what are they?

Answer 4

1. thorns in bouganvillea and spines in Acacia.

2. Calotropis produces highly poisonous cardiac glycoside

Question 5

competition and its example

Answer 5

none of the two species were benefitted.eg., the Abingdon tortoise became extinct within a decade after goats were introduced in the Galapagos island because goats had greater browsing efficiency

Question 6

Gause’s “Competitive Exclusion Principle”

Answer 6

states that two closely related species competing for the same resource cannot co exist indefinitely and the competitively inferior one will be eliminated eventually

Question 7

parasitism and its example

Answer 7

parasite and the host co evolve. example: lice on human and tick on dogs