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प्रश्न
What is carbon dating?
उत्तर
- Carbon consumption of animals and plants stops after death and only the decaying processes of C-14 take place continuously.
- The ratio of C-14 to C-12 changes constantly with time as C-12 is nonradioactive in dead plants and animals.
- The time passed since the death of a plant or animal can be calculated by carbon dating i.e. by measuring the radioactivity of C-14 and the ratio of C-14 to C-12 present in the remains of the dead organism.
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संबंधित प्रश्न
Given below is the list of vegetables available in the market. Select from these the two vegetables having homologous structures:
Potato, sweet potato, ginger, radish, tomato, carrot, okra (Lady’s finger)
(A) Potato and sweet potato
(B) Radish and carrot
(C) Okra and sweet potato
(D) Potato and tomato
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 is a correct set of homologous organs?
(a) Forelimbs of frog, bird and lizard
(b) Spine of cactus and thorn of bougainvillea
(c) Wings of bat and wings of butterfly
(d) Wings of a bird and wings of a bat
An example of homologous organs is
Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.
Attempt giving a clear definition of the term species.
Enlist any four sequential evolutionary names of human ancestors.
Give the importance of fossil in support of organic evolution
Human tailbone is a vestigial organ. Explain.
Name two animals having homologous organs and two having analogous organs. Name these organs.
Out of bacteria, spider, fish and chimpanzee, which organism has a better body design in evolutionary terms? Give reason for your answer.
Wing of an insect and forelimb of a bird are :
(a) analogous organs
(b) analeptic organs
(c) homologous
(d) homophobic 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
The organs P and Q of two animals have different structures but similar functions. On the other hand, the two organs R and S of two other animals have the same basic structure but different functions.
(a) What are the organs like P and Q known as?
(b) Name the organs like P and Q. Also name the animals which have such organs.
(c) What are the organs like R and S called?
(d) Name the organs like R and S. Also name the animals which have such organs.
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
Write short notes based upon the information known to you.
Embryology
Complete the following chart:
Differentiate between connecting links and the missing links.
Very short answer question.
What are homologous organs?
Long answer question.
Would you consider wings of butterfly and bat as homologous or analogous and why?
Similarities in the initial stages indicate the _______ evidence.
Appendix : vestigial organ : : Peripatus : ____________
The decaying process of C-14 occurs continuously in dead organisms only.
The degenerated and non-functional organs found in an organism are called ______.
How do you differentiate homologous organs from analogous organs?
Select the CORRECT match.
Cucurbits do not develop thick and woody stem as they are:
Evolutionary convergence is the development of:
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Animal husbandry and plant breeding programmes are the examples of ______.
The bones of forelimbs of whale, bat, cheetah and man are similar in structure, because ______.
Analogous organs arise due to ______.
Fossils are generally found in ______.
I am the connecting link of annelida and arthropoda. What is my name?
Give a scientific reason.
Morphological evidences suggest that dog, sheep and wolf have a common origin.
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.
Write avian characters of Archaeopteryx.
Industrial melanism was highlighted by ______.
Give examples of homologous organs and analogous organs in plants.
