Tag: natural selection
Questions Related to natural selection
The major/ ultimate source of variations are
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Polyploidy
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Mutations
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Chromosome aberrations
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Segregation
- Point mutation e.g. nonsense and missense mutations
- Frame-shift mutation e.g. insertion or deletion mutations
Cannibals feed on
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Carcases
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Blood
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Carnivores
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Members of own species
Discontinuous variations are :
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Essential features
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Acquired character
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Non-essential changes
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Mutations
Height in humans is
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Somatogenic variation
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Discontinuous variation
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Continuous variation
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Both B and C
A.Somatogenic variation – These are acquired variations and non inheritable in nature. Eg:phenotypic plasticiy.
B.Discontinuous variations – These are responsible for the formation of a new species and the organism, thus, formed is called mutant. Eg:Mutations.
C.Continuous variations – These are fluctuating variations and cannot give rise to new species. Eg:Human height.
So, the correct option is ‘Continuous variations’.
Primary source of allelic variation is
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Independent assortment
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Recombination
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Mutation
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Polyploidy
Primary source of allelic variation is recombination. Recombination is the natural process of breaking and rejoining DNA strands to produce new combinations of genes and, thus, generate genetic variation. This is the phenomenon that occurs during meiosis I.
Mutations are responsible for.
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Extinction of organisms
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Variations in population
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Increase in population
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Maintaining genetic continuity
Recombinations and variations in eucaryotic organisms are due to
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Mitosis and meiosis
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Fertilization and mitosis
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Meiosis and fertilisation
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Meiosis and amitosis
The process of forming new allelic combination in offspring by exchanges between genetic materials of parents is called Recombination.
Variation is a change or slight difference in condition, amount, or level, typically within certain limits appear in the progeny compared with parents.
Recombination and variations appear in sexually reproducing organisms during meiosis and fertilization.
So, the correct option is ‘Meiosis and fertilization’.
Some individuals produce lesser amounts of insulin. It is a type of
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Physiological variation
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Behavioural variation
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Morphological variation
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All the above
- Physiological variation is related to the differences in the ways individuals of the same species react to conditions in their environment because of difference in their functioning of the body. Production of insulin is an example of physiological variation.
- So, the correct option is 'Physiological variation'
Mutation, selection and genetic drift are three important forces which are responsible for evolutionary changes
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True
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False
Evolution is dependent on the natural selection , genetic drift , gene flow , mutation are the main factors responsible for evolution .
Aspects such as sedentary habit, territoriality, etc., not aiding diversification are classified as
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Reproductive isolation
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Mutational effects
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Biological barriers
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Genetic incompatibility