The concept of chemical evolution is based on
1. crystallization of chemicals
2. interaction of water, air, and clay under intense heat
3. effect of solar radiation on chemicals
4. the possible origin of life by the combination of chemicals under suitable environmental conditions
Which one of the following describes correctly the homologous structures?
1. Organs appearing only in embryonic stage and disappearing later in the adult
2. Organs with anatomical similarities, but performing different functions
3. Organs with anatomical dissimilarities, but performing same functions
4. Organs that have no function now, but had an important function in ancestors
Correct order is [1991]
1. Palaeozoic Archaeozoic Coenozoic
2. Archaeozoic Palaeozoic Proterozoic
3. Palaeozoic Mesozoic Coenozoic
4. Mesozoic Archaeozoic Proterozoic
Which was absent in the atmosphere at the time of origin of life?
1. NH3
2. H2
3. O2
4. CH4
Evolutionary convergence is the development of
1. common set of characters in the group of different ancestry
2. dissimilar characters in closely related groups
3. common set of characters in closely related groups
4. random mating
The finches of Galapagos islands provide an evidence in favour of
1. special creation
2. evolution due to mutation
3. retrogressive evolution
4. biogeographical evolution
What is genetic equilibrium?
(1) When all the alleles of a gene are present in a population in equal frequencies
(2) When the number of heterozygotes in a population are equal to the number of either of the homozygote
(3) When the number of heterozygotes in a population are equal to the number of either of the homozygote
(4) When the frequency of particular genes or alleles remain constant in a population through generations
The presence of the monotremes and marsupials in the Australian continent can be explained by:
1. Convergent evolution
2. Adaptive radiation
3. Punctuated equilibrium
4. Gene flow
Which of the following would lead to deviation from Hardy-Weinberg equilibrium?
1. Random mating
2. Lack of mutations
3. No gene flow or gene migration
4. Natural selection
The now extinct reptile group that evolved into mammals was:
1. Therapsids
2. Dinosaurs
3. Thecodants
4. Sauropsids