Tag: variation and its type
Questions Related to variation and its type
Which is the source of variations?
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Mutation
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Recombination
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Deletion
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All of the above
Mutations, recombinations and deletions all are the sources of genetic variation. A Mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene. Recombination involves the exchange of genetic material either between multiple chromosomes or between different regions of the same chromosome. Deletion is a mutation in which a part of a chromosome or a DNA sequence is missing.
The variations are caused by
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Internal changes
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Environment
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Hybridization
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All of the above
Variations can be defined as the difference in characters among the individuals of same species, it gets affected by internal changes, environmental changes, hybridization etc.
Which is a source of variation and genetic diversity that is shared between prokaryotes and eukaryotes?
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Random fertilization involving a unique sperm and a unique egg
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Independent assortment of each chromosome pair during metaphase I of meiosis
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Crossing-over during prophase I of meiosis
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Random mutation
The genetic material in prokaryotes is not confined into a nucleus and they do not have a nuclear membrane and the genetic material is present in the form of chromatin and cytoplasm and there is no chance of crossing over during meiosis and no fertilization but random mutations do arise in them and it results change in the genetic material.
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’.