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प्रश्न
The person A has only B chromosomes in all its gametes. On the other hand, another person C has chromosome D in half of gametes and chromosome E in the other half of gametes. When chromosomes B and D combine during fertilisation, a female zygote results. On the other hand, combination of B and E chromosomes produces a male zygote.
(a) What are chromosomes (i) B (ii) D, and (iii) E?
(b) Out of B, D and E, which two chromosomes are of the same type?
(c) Which chromosome is smaller in size?
(d) What is the general name of chromosomes such as B and E?
(e) Out of the two persons A and C, which one is (i) male, and (ii) female?
उत्तर
(a) (i) B is X chromosome; (ii) D is also X chromosome; (iii) E is Y chromosome.
(b) Chromosomes B and D are of same type.
(c) Chromosome E is smaller in size.
(d) Chromosomes B and E are called sex chromosomes.
(e) (i) A is female; (ii) C is male.
APPEARS IN
संबंधित प्रश्न
Answer the following questions related to sex determination in human beings:
i. What is sex chromosome?
ii. How many pairs of chromosomes are present in human beings?
iii. How is the sex of the human offspring determined?
iv. Draw a diagram depicting sex determination in man.
Fill in the following blank with suitable word :
The...............chromosomes for a ............are XX whereas that for a ..............are XY.
Explain how, sex is determined in human babies.
In a human, how many chromosmes are present in a sperm in the testes?
A family consists of two parents and their five children and the pedigree chart below shows the inheritance of the trait colour blindness in them.
Who is colour blind in the parents – the Father or the Mother?
Choose the correct answer:
Chromosomes identical in male and female are called __________
Choose the correct answer:
A man can transfer his sex-linked gene to his ______________
What is parthenogenesis?
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.
