Short Answer TypeA colour-blind child is born to a normal couple. Work out a cross to show how it is possible. Mention the sex of this child.
Mendel published his work on inheritance of characters in 1865, but it remained unrecognized till 1900. Give three reasons for the delay in accepting his work.
Women are often blamed for producing female children. Consequently, they are ill-treated and ostracized. How will you address this issue scientifically if you were to conduct an awareness programme to highlight the values involved?
It is not appropriate to blame women for producing female children because scientifically it is the father who determines the sex of the baby.
The scientific explanation for the following is:
The chromosome pattern in human females is XX and human males are XY. Males are heterogametic and produce two types of gametes one carrying X and the other carrying Y. The females are homogametic and produce same type of gamete carrying X chromosome. The sex of the child depends on the sperm that fuses with the ovum. If the fertilizing sperm has an X chromosome, then the baby would be a female and if a sperm with Y chromosome fuses with the ovum, it will develop into a male child. Thus, males are responsible for determination of the sex of a child. So, we should not blame women for the birth of a female child and stop ill-treating them.
Name the tropical sugar cane variety grown in South India. How has it helped in improving the sugar cane quality grown in North India?
Identify ‘a’, ‘b’ and ‘c’ in the following table:
|
No. |
Crop |
Variety |
Insect Pests |
|
1. |
Brassica |
Pusa Gaurav |
(a) |
|
2. |
Flat bean |
Pusa Sem 2 |
(b) |
|
3. |
(c) |
Pusa Sawani |
Shoot and fruit borer |
Why are beehives kept in a crop field during flowering period? Name any two crop fields where this is practiced.
How did the process of RNA interference help to control the nematode from infecting the roots of tobacco plants?
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