Class 12th Biology 2015 Set2 Delhi Board Paper Solution
Question 3
Indiscrimate diagnostic practices using X-rays etc., should be avoided. Give one reason.
Answer
X-rays are ionising radiations. They cause adverse effects in children in the form of genital changes; that is, they alter the genetic make-up of an organism.
Popular Questions of Class 12th biology
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- Q:- Why is reproduction essential for organisms? Answer
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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:- What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.
- Q:- With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.
- Q:- Explain the Law of Dominance using a monohybrid cross.
Recently Viewed Questions of Class 12th biology
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- Q:- Give examples to prove that microbes release gases during metabolism.
- 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:- List two essential roles of ribosome during translation.
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(a) 100%
(b) 50 %
(c) 1-5%
(d) 2-10% - Q:- Name the three important components of biodiversity.