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प्रश्न
Why did T. H. Morgan select Drosophila melanogaster to study sex linked genes for his lab experiments ?
उत्तर
T. H. Morgan selected Drosophila melanogaster to study sex-linked genes in his lab experiment due to the following reasons:
(i) Drosophila melanogaster has short life cycle, high reproductive rate and has sex chromosomes similar to that of humans, that is, females have XX chromosomes while males have XY chromosomes (however, their sex determination mechanism is different from humans).
(ii) Sex-linked traits such as red eye colour and white eye colour are found only in Drosophila melanogaster, where white eye colour in males is a sex-linked recessive trait.
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संबंधित प्रश्न
The sex of a child is determined by which of the following?
(a) the length of the mother's pregnancy
(b) the length of time between ovulation and copulation
(c) the presence of and X chromosome in an ovum
(d) the presence of a Y chromosome in a sperm
A zygote which has inherited an X chromosome from the father will develop into :
(a) baby boy
(b) baby girl
(c) adult
(d) either boy or girl
Drone of the honeybees shows haploid number of chromosomes. Illustrate.
Read the following statements and select the correct option.
i. If sperm containing Y chromosome fertilizes the ovum, then diploid zygote is formed that grows into a male child.
ii. If sperm containing X chromosome fertilizes ovum, then diploid zygote is formed, that grows into a female child.
Chromosomal constitution of normal human females can be written as ______.
In XO type of sex determination ______.
Which of the following is an example of genetic variation?
Which of the following determines the sex of a child?
All human chromosomes ate not paired. Most human chromosomes have a maternal and a paternal copy, and we have 22 such pairs. But one pair called the sex chromosomes, is odd in not always being a perfect pair. Women have a perfect pair of sex chromosomes. But men have a mismatched pair in which one is normal sized while the other is a short one.
(a) In humans, how many chromosomes are present in a Zygote and in each gamete?
(b) A few reptiles rely entirely on environmental cues for sex determination. Comment.
(c) "The sex of a child is a matter of chance and none of the parents are considered to be responsible for it." Justify it through flow chart only.
OR
(c) Why do all the gametes formed in human females have an X chromosome?
What is sex determination? Explain the mechanism of sex determination in the case of birds.
