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प्रश्न
Answer the following question:
How is sex determined in human beings? Explain with the help of a diagram.
उत्तर
- In human beings, the gametes from the male parent decide the sex of the baby.
- In human beings, there are 22 pairs of autosomes and 1 pair of sex chromosomes.
- In human male gametes, two dissimilar sex chromosomes XY are present whereas in females two similar sex chromosomes XX are present.
- All children inherit 'X' chromosomes from their mother and 'X or 'Y' from their father.
- If it is X chromosome from father, then the offspring will be a daughter, and if 'Y' chromosomes, then it will be a son.
- Hence, the gametes from the male parent decide the sex of the baby.
APPEARS IN
संबंधित प्रश्न
Explain sex determination in human beings.
Write the types of sex-determination mechanisms the following crosses show. Give an example of each type.
(i) Female XX with Male XO
(ii) Female ZW with Male ZZ
How is the sex of the child determined in human beings?
Fill in the following blank with suitable word :
Genes always work in ................ .
In a human, how many chromosmes are present in a sperm in the testes?
The human animal which has an XY pair of chromosomes is called :
(a) male
(b) hybrid
(c) female
(d) doomed
A normal cell of human body contains 23 pairs of chromosomes. The number of chromosomes in a sex cell (sperm or ovum) of a human being is most likely to be :
(a) 46
(b) 23
(c) 21
(d) 42
The number of pair(s) of sex chromosomes in the zygote of humans is :
(a) one
(b) two
(c) three
(d) four
A couple with a newborn baby is troubled that the child does not resemble either of them. Suspecting that a mixup occurred at the hospital, they check the blood type of the infant. It is type O. Because the father is type A and the mother type B, they conclude that a mixup has definitely occurred. Are they correct? Give reason for your answer.
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?
________ shows haplo-diploid type of sex-determination.
Choose the correct answer from the four options given below :
In a human male, a sperm will contain :
Choose the correct answer :
Human sex chromosomes are __________
Complete the following sentence with appropriate word:
______are the alternative forms of a gene producing different effects.
Explain the mechanism of sex determination in humans with a suitable chart.
Which of the following is incorrect regarding ZW-ZZ type of sex determination?
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.
From the following which option correctly represents the normal genetic constitution of a ovum?
Sex is determined in human beings ______.
ZZ / ZW type of sex determination is seen in ______.
Grasshopper is an example of XO type of sex determination in which the males have ______.
Which of the following combination of chromosome numbers represents the correct sex determination pattern in honey bees?
Which of the following decides the sex of the child?
Which of the following is an example of genetic variation?
The maleness of a child is determined by ______
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?
Which pair of sex chromosome will determine a male?
A zygote which has Y chromosome inherited from the father will develop into a ______.
