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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
State the connecting links between Peripatus with Annelida and Arthopoda.
What are vestigial organs?
(a) Select the homologous structures from the combinations given below:
(i) Forelimbs of whales and bats
(ii) Tuber of potato and sweet potato
(iii) Eyes of octopus and mammals
(iv) Thorns of Bougainvillea and tendrils of Cucurbita
(b) State the kind of evolution they represent.
Study the following statements:-
I. Wings of birds and wings of bats are homologous organs.
II. Wings of birds and wings of insects are modified forelimbs.
III. Wings of birds and wings of insects are analogous organs.
IV. Wings of birds and forelimbs of horse are homologous organs.
The correct statements are
(A) I and II
(B) II and III
(C) III and IV
(D) I and IV
Which of the following pairs of two vegetables represent the correct homologous structures?
(A) Sweet potato and potato
(B) Sweet potato and tomato
(C) Carrot and potato
(D) Radish and carrot
Write the similarity between the wing of a butterfly and the wing of a bat. What do you infer from the above with reference to evolution?
Select two pairs from the following which exhibit divergent evolution. Give reasons for your answer.
(i) Forelimbs of cheetah and mammals
(ii) Flippers of dolphins and penguins
(iii) Wings of butterflies and birds
(iv) Forelimbs of whales and mammals
Attempt giving a clear definition of the term species.
Human tailbone is a vestigial organ. Explain.
Differentiate between analogous and homologous structures.
The forelimbs of a frog, a bird and a man show the same basic design (or basic structure) of bones. What name is given to such organs?
The wings of a housefly and the wings of a sparrow are an example of :
(a) analogous organs
(b) vestigial organs
(c) respiratory organs
(d) homologous organs
Write short notes based upon the information known to you.
Connecting link
Write the names of those animals in whom some vestigial organs in human body are functioning.
“Appearance of melanised moths post-industrialisation in England is a classic example of evolution by natural selection.” Explain.
With the help of diagrams, describe emasculation and bagging.
The most common types of fossils are ------------------------.
Long answer question.
Would you consider wings of butterfly and bat as homologous or analogous and why?
______ is a vestigial organ in human beings.
The decaying process of C-14 occurs continuously in dead organisms only.
Give scientific reason.
Peripatus is said to be the connecting link between Annelida and Arthropoda.
Give scientific reason.
Vertebrates have slowly originated from invertebrates.
Define the evidence of evolution shown in the figure.
Tendons and ligaments are examples of ______.
The process of mating of individuals, which are more closing related than the average of the population to which they belong is called ______.
Which is not a vestigial organ in a man?
Which of the following is used as an atmospheric pollution indicator?
How do we compute the age of a living tree?
The evolutionary story of moths in England during industrialisation reveals, that 'evolution is apparently reversible'. Clarify this statement.
You have studied the story of Peppermoths in England. Had the industries been removed, what impact could it have had on the moth population? Discuss.
Give a scientific reason.
Morphological evidences suggest that dog, sheep and wolf have a common origin.
What is the function of the appendix of our digestive system?
As shown in figure below some organisms that share a common ancestor have features that have different functions, but similar structures.
These are known as ______. Give example.
Find the odd one out:
Define the term:
Homologous organs
Pick the odd man out:
