Class 12th Biology 2017 Set2 Delhi Board Paper Solution
Describe the structure of a nucleosome.
The negatively charged DNA is wrapped around positiverly charged histone octamer to form a structure called nucleosome. A typical nucleosome consist of 200 bp of DNA helix. It consist four type of proteins which occurs in pairs :
H2A, H2B, H3 and H4
Popular Questions of Class 12th biology
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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:- 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
- Q:- Suggest some methods to assist infertile couples to have children.
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- Q:-
Fill in the blanks:
(a) Humans reproduce __________. (asexually/sexually)
(b) Humans are__________. (oviparous/viviparous/ovoviviparous)
(c) Fertilization is __________ in humans. (external/internal)
(d) Male and female gametes are __________. (diploid/haploid)
(e) Zygote is __________. (diploid/haploid)
(f) The process of release of the ovum from a mature follicle is called__________.
(g) Ovulation is induced by a hormone called the __________.
(h) The fusion of male and female gametes is called _____________.
(i) Fertilisation takes place in _____________.
(j) Zygote divides to form _____________which is implanted in uterus.
(k) The structure which provides vascular connection between fetus and uterus is called ____________. - Q:- Draw a well-labelled diagram of an antibody molecule.
- Q:-
Explain the following terms with example
(a) Co-dominance
(b) Incomplete dominance - Q:- Name the functions of the following.
(a) Corpus luteum
(b) Endometrium
(c) Acrosome
(d) Sperm tail
(e) Fimbriae - Q:- Name the parts of an angiosperm flower in which development of male and female gametophyte take place.
- Q:- In which way have microbes played a major role in controlling diseases caused by harmful bacteria?
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