Long Answer TypeGive reasons why:
a. Most zygotes in angiosperms divide only after certain amount of endosperm is formed.
b. Groundnut seeds are exalbuminous and castor seeds are albuminous.
c. Micropyle remains as a small pore in the seed coat of a seed.
d. Integuments of an ovule harden and the water content is highly reduced, as the seed matures.
e. Apple and cashew are not called true fruits.
A. Why is haemophilia generally observed in human males? Explain the conditions under which a human female can be haemophilic.
B. A pregnant human female was advised to undergo M.T.P. It was diagnosed by her doctor that the foetus she is carrying has developed from a zygote formed by an XX egg fertilized by Y-carrying sperm. Why was she advised to undergo M.T.P.?
A. Haemophilia is sex-linked recessive disease; it is transmitted from unaffected female carrier to male child with haemophilia. It is an X-linked recessive gene.
The females have XX condition and thus may be heterozygous carrying one normal X chromosome and diseased/affected X. Since the disease is a recessive one, therefore, it does not express until it is present in the homozygous condition.
The males have XY condition. The presence of the diseased allele of X will result in the person to develop the disease. The Y has no allele for this disease. Thus the probability of the males getting affected is much more than the females.
B. MTP stands for medical termination of pregnancy (MTP) or it may be called as abortion in common language.
The egg usually has one of the two X-chromosomes, but in this case, the pregnant female has egg having XX condition. The doctor advises for M.T.P. because her foetus may be carrying an abnormal number of chromosomes as the fertilisation of the XX egg by the Y sperm will create a trisomy condition.
A. Describe the characteristics a cloning vector must possess.
B. Why DNA cannot pass through the cell membrane? Explain. How is a bacterial cell made competent to take up recombinant DNA from the medium?
If a desired gene is identified in an organism for some experiments, explain the process of the following:
(i) Cutting this desired gene at specific location
(ii) Synthesis of multiple copies of this desired gene
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