CBSE
The important gas which was absent during the formation of Earth is
oxygen
hydrogen
nitrogen
carbon dioxide
Which one of the following is the most primitive ancestor of man?
Homo habilis
Australopithecus
Ramapithecus punjabicus
Homo neanderthalensis
Which one of the following ancestors of man first time showed bipedal movement
Australopithecus
Cro-magnon
Java ape man
Peking mann
Bursa fabricius is an important organ of birds. This organ is associated with
generation of basophil
production of uric acid
metabolism of fatty acids
generation of B-cell
According to Darwin, the organic evolution is due to
intraspecific competition
interspecific competition
competition within closely related species
reduced feeding efficiency in one species due to the presence of interfering species
The process by which organisms with different evolutionary history evolve similar phenotypic adaptations in response to a common environmental challenge, is called
natural selection
convergent evolution
non-random evolution
adaptive radiation
Homo erectus evolved during
Oligocene
Pliocene
Pleistocene
Miocene
Variation in gene frequencies within populations can occur by chance rather than by natural selection. This is referred to as
genetic flow
genetic drift
random mating
genetic load
The tendency of population to remain in genetic equilibrium may be disturbed by
random mating
lack of migration
lack of mutations
lack of random mating
Mammals have originated from which of the following
Pisces
Amphibia
Reptilia
Aves