Class 12th Biology 2018 Set1 Delhi Board Paper Solution
Question 3
How do cytokine barriers provide innate immunity in humans?
Answer
Cytokines including interferons, lymph Okines, necrosis factor etc. protect the non-infected cells from further viral infection by modulating the immune system in response to infection.
Popular Questions of Class 12th biology
- Q:- What is spermatogenesis? Briefly describe the process of spermatogenesis.
- Q:- Why is reproduction essential for organisms? Answer
- Q:- Write a short note on
(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:- With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.
- Q:- Explain the Law of Dominance using a monohybrid cross.
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(a) Transcription
(b) Polymorphism
(c) Translation
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(a) Hibernation and Aestivation
(b) Ectotherms and Endotherms - Q:- State True/False with explanation
(a) Abortions could happen spontaneously too. (True/False)
(b) Infertility is defined as the inability to produce a viable offspring and is always due to abnormalities/defects in the female partner. (True/False)
(c) Complete lactation could help as a natural method of contraception. (True/False)
(d) Creating awareness about sex related aspects is an effective method to improve reproductive health of the people. (True/False) - Q:- Name the primary and secondary lymphoid organs.
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