Assertion : Holoblastic cleavage with almost equal-sized blastomeres is a characteristic of placental animals.

Reason : Eggs of most mammals, including humans, are of centrolecithal type.

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

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

• If Assertion is true statement but Reason is false

• If both Assertion and Reason are false statements

Assertion : Old age is not an illness. It is a continuation of life with decreasing capacity for adaptation.

Reason : Cessation of mitosis is a normal genetically programmed event.

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

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

• If Assertion is true statement but Reason is false

• If both Assertion and Reason are false statements

Prototherians are the connecting links between:

• amphibians and aves

• reptiles and mammals

• fishes and amphibians

• reptiles and amphibinas

Assertion : Bats and whales are classified as mammals.

Reason : Bats and whales have four-chambered heart.

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

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

• If Assertion is true statement but Reason is false

• If both Assertion and Reason are false statements

Assertion : Organochlorine pesticides are organic compounds that have been chlorinated.

Reason : Fenitrothion is one of the organochlorine pesticides. 

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

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

• If Assertion is true statement but Reason is false

• If both Assertion and Reason are false statements

Assertion: Natural selection is the outcome of differences in survival and reproduction among individuals that show variation in one or more traits.

Reason: Adaptive forms of a given trait tend to become more common; less adaptive ones become less common or disappear.

• 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.

Assertion: From evolutionary point of view, human gestation period is believed to be shortening.

Reason: One major evolutionary trend in humans has been the larger head undergoing relatively faster growth rate in the foetal stage.

• 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.

The pioneers in the field of 'organic evolution' are:

• Karl Landsteiner, Hugo de Vries, Malthus

• Darwin, Hugo de Vries, Lamarck, Huxley

• Lamarck, Karl Landsteiner, Malthus, Hugo de Vries

• Darwin, Lamarck, Karl Landsteiner, Hugo de Vries

Assertion : All birds, except the ones like koel (cuckoo) build nests for retiring and taking rest during night time (day time for nocutrnal).

Reason : Koel lays its eggs in the nests of tailor bird.

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

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

• If Assertion is true statement but Reason is false

• If both Assertion and Reason are false statements

A force which acts against the achievement of highest possible level to population growth is known as

• population pressure

• saturation level

• carrying capacity

• environmental resistance