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प्रश्न
What do you mean by vestigial structures? Name four vestigial organs found in man.
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उत्तर
1. Ill developed structures or structures which are of no use are sometimes found in both plants and animals. They are referred to as vestigial organs. The same organ may be functional in one organism but vestigial in another.
2. Vermiform appendix of man is one such organ. The reason could be that human ancestors were eating uncooked food with considerable amount of cellulose in it. The normal function of caecum and appendix
in mammals is the digestion of cellulose.
3. Man shows a number of other vestigial organs. About 100 have been named. A few examples are ear muscles, wisdom teeth, plica semilunaris (representing nictitating membrane of the eye), coccyx (reduced tail) etc.
4. In plants, the scale like leaves on the Indian pipe, a plant which has lost its chlorophyll and became saprophytic in nature, is vestigial.
5. There are certain flowers in which stamens do not bear anthers.
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संबंधित प्रश्न
Mammals : _________ : : Amphibia : Fishes
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(a) What could the animals A, B, C, D and E be?
(b) Why are the forelimbs of animals A, B, C, D called homologous organs?
(c) What does the existence of homologous organs in animals A, B, C and D tell us about their ancestors ?
(d) Why are the modified forelimbs of animal A and the wings of animal E called analogous organs?
(e) State whether animals A and E have a common ancestor or not.
Select a set of homologous organs from the following:
(A) Wings of a bat and wings of a butterfly
(B) Wings of a pigeon and wings of a bat
(C) Wings of a butterfly and wings of a pigeon
(D) Forelimbs of a duck, forelimbs of a cow and forelimbs of a lizard
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Complete the following chart:
Explain the importance of Anatomical evidences with examples.
______ is a vestigial organ in human beings.
Match the following.
| Column A | Column B |
| 1) Morphological evidences | a) Tail-bone or wisdom teeth |
| 2) Paleontological evidences | b) Leaf venation |
| c) Fossils |
Give scientific reason.
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Homologous organs and vestigial organs are examples of ______ type of evidence in evolution.
Select the CORRECT match.
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Study of fossils is ______.
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