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प्रश्न
A woman has only daughters. Analyse the situation genetically and provide a suitable explanation.
उत्तर
In humans, women produce one type of eggs (all with X chromosome) and men produce two types of sperms - 50% with X chromosome and 50% with Y chromosome. All the children of a woman receive X chromosome from her but second sex chromosome which is received from father, can be X or Y. So, the sex is determined by the sex chromosome present in the sperms of the father. If a woman has only daughters, it means father has contributed sperm with X chromosome.
APPEARS IN
संबंधित प्रश्न
Write notes on sex determination in the unborn baby.
Explain how, sex is determined in human babies.
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
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?
Brief about female heterogamety.
Explain the mode of sex determination in honeybees.
Diploid larvae which get royal jelly as food develops into ____________ and other develops into workers (sterile females).
In human males all the chromosomes are paired perfectly except one. This/these unpaired chromosomes is/are ______.
- large chromosome
- small chromosome
- Y-chromosome
- X-chromosome
Which of the following statements is not true with respect to variation?
How is the sex of a newborn individual determined in different species of animals? Give three examples to support your answer.
