Class 12th Biology 2017 Set1 Delhi Board Paper Solution
Question 3
What role does an individual organism play as per Darwin’s theory of natural selection?
Answer
According to Darwin, fitness refers ultimaterly and only to reproductive fitness. Those who are better fit in an environment, leave more progeny than others.
Popular Questions of Class 12th biology
- Q:- What is spermatogenesis? Briefly describe the process of spermatogenesis.
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(a) Adaptations of desert plants and animals
(b) Adaptations of plants to water scarcity
(c) Behavioural adaptations in animals
(d) Importance of light to plants
(e) Effect of temperature or water scarcity and the adaptations of animals. - Q:- With a neat diagram explain the 7-celled, 8-nucleate nature of the female gametophyte.
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- Q:- Explain the Law of Dominance using a monohybrid cross.
Recently Viewed Questions of Class 12th biology
- Q:- Identify True/False statements. Correct each false statement to make it true.
(a) Androgens are produced by Sertoli cells. (True/False)
(b) Spermatozoa get nutrition from Sertoli cells. (True/False)
(c) Leydig cells are found in ovary. (True/False)
(d) Leydig cells synthesise androgens. (True/False)
(e) Oogenesis takes place in corpus luteum. (True/False)
(f) Menstrual cycle ceases during pregnancy. (True/False)
(g) Presence or absence of hymen is not a reliable indicator of virginity or sexual experience. (True/False) - Q:- Give an account of energy flow in an ecosystem.
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(a) Plants are called as_________ because they fix carbon dioxide.
(b) In an ecosystem dominated by trees, the pyramid (of numbers) is _________ type.
(c) In aquatic ecosystems, the limiting factor for the productivity is _________.
(d) Common detritivores in our ecosystem are_________.
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Adenine, Cytidine, Thymine, Guanosine, Uracil and Cytosine. - Q:- Explain why meiosis and gametogenesis are always interlinked?
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(a) Surgical methods of contraception prevent gamete formation.
(b) All sexually transmitted diseases are completely curable.
(c) Oral pills are very popular contraceptives among the rural women.
(d) In E. T. techniques, embryos are always transferred into the uterus. - Q:- What measure would you take to prevent water-borne diseases?