Variations


 
 
Concept Explanation
 

Variations

Variations are the differences in the characters (traits) among the individuals of a species are called variations. Variations may also be produced during asexual mode of reproduction (due to small inaccuracies in copying of DNA), but sexual reproduction produces a large number of variations, e.g. in plants, less variations are seen in comparison to animals which reproduce mainly by sexual reproduction.

  • Variations are beneficial and necessary for organic evolution. These variations may environmental or genetic. Transmission of characters (resemblances as well as variations) from parents to the offspring i.e. from one generation to the next is called heredity.
  • Although the offsprings inherit the characters (or traits) of the parents and resemble them very closely, but the resemblance is not complete in all respects.
  • The offsprings are never a true copy of the parents. In fact, no two individuals are exactly alike and the members of any one species differ from one another in some characters (or traits) or the other.
  • These differences are known as variations. The differences in the characters or traits shown by the individuals of a species, and also by the offsprings of the same parents are referred to as variations.
  • Here is an example of variations in human beings which involves our ears. In most of the people the earlobe is hanging, it is called free earlobe. In some people the earlobe is closely attached to the side of the head and it is called closely attached earlobe.
  • So free ear lohes and attached earlobe are the two variations found in human population.
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    Sample Questions
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    Question : 1

    Which of the following are correct ?

    (a) Variations are the differences in the characters among the individuals of a species.

    (b) Variations may also be produced during asexual mode of reproduction .

    (c) Transmission of characters  from parents to the offspring i.e. from one generation to the next is called evolution .

    Right Option : A
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    Explanation
    Question : 2

    Variations in human beings which involves our ears are  ____________________ earlobes.

    Right Option : C
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    Explanation
    Question : 3

    The differences in the traits among the individuals of a species are called __________________ .

    Right Option : C
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    Explanation
     
     
     
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