Following are the two statements regarding the origin of life
I. The earliest organisms that appeared on the earth were non-green and presumably anaerobes.
II. The first autotrophic organisms were the chemoautotrophs that never released oxygen.
Of the above statement which one of the following options is correct?
II is correct but I is false
Both I and II are correct
Both I and II are false
Both I and II are false
B.
Both I and II are correct
The first organisms were chemoautotrophic anaerobes.
The tendency of population to remain in genetic equilibrium may be disturbed by
random mating
lack of migration
lack of mutations
lack of mutations
D.
lack of mutations
According to Hardy-Weirberg principle, allele frequencies in a population are stable and is constant from generation to generation allele frequencies in a population will remain constant over generations only if the following condition are met
i) There is no mutation no gene flow and all mating is random
ii) All genotypes reproduce equally well (i.e., no natural selection,)But their conditions rarely met in nature.
Which of the following structures is homologous to the wing of a bird?
Wing of a moth
Hind limb of a rabbit
Flipper of whale
Flipper of whale
C.
Flipper of whale
Wings of bird and flipper of whale are modified forelimbs of the two organisms so have same origin wings help in flying and flippers help in swimming but thus perform the different functions
According to Darwin, the organic evolution is due to
intraspecific competition
interspecific competition
competition within closely related species
competition within closely related species
B.
interspecific competition
Darwin stated that the organic evolution is due to interspecific competition. it is the competition between members of different species. Intraspecific competition occurs amongst members of the same species for obtaining optimum amounts of their food, shelter, mate, water, light, species etc. Closely species compete cannot cause evolution. Reduced feeding efficiency in one species due to the presence of interfering species is due to strugle for existance.
The process by which organisms with different evolutionary history evolve similar to a common environmental challenge is called
natural selection
convergent evolution
non-random evolution
non-random evolution
B.
convergent evolution
Convergent evolution occurs in an unrelated group of organisms. It is the development of similar functional structures but in related groups.
The process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography is called adaptive radiation. Natural selection is the basis of evolution.