The permanent decrease in population number occurs due to

• migration

• natality

• emigration

• mortality

Study of Ecology of population is called

• Autecology

• Synecology

• Ecotype

• Demecology

The process where a population inhibits the growth of other population without affecting itself is known as

• amensalism

• mutualism

• parasitism

• commensalism

Which of the following is not a factor that would limit the growth of a population

• Food shortage

• Immigration

• Disease

• Famine

A small rise in the body temperature of humans is corrected by

(i) sweating
(ii) dilating the skin arteries
(iii) constricting the skin arteries
(iv) increased tension of muscles in the skin

• (i) only

• (ii) only

• (i) and (ii)

• (iii) and (iv)

Which of the following associations shows mutualism

• Fig and wasp

• Barnacles on whale

• Roundworms in human intestine

• Orchids on mango tree

167.

Which is correctly labelled with respect to the given diagram

• B: Logistic curve

• C: Carrying capacity

• C: Exponential curve

• A: Carrying capacity

Assertion: Some marine animals find it difficult to live in fresh water and vice versa.

Reason: Some animals can tolerate a narrow salinity range, while others can tolerate a wide salinity range.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false

What are labelled phases A, B and C in given sigmoidal growth curve.

• A	B	C
  stationery	Log	Lag

• A	B	C
  Lag	stationery	Log

• A	B	C
  Log	Lag	stationery

• A	B	C
  Lag	Log	stationery

Monarch butterfly escapes from predators by

• foul smell

• bitter taste

• colour combination

• rough skin