Human Reproduction — BIOLOGY STD 12 Science — Question

Anita was happy when she gave birth to her first child. Her in-laws were dissatisfied at her not giving birth to a male child and blamed Anita. Anita tried to convince her in-laws that she had no role in the child's gender. They understood the biological reason but were yet to be satisfied. Anita's husband took up the matter and convinced the parents.
i. What values did Anita's husband show in the above situation?
ii. What governs sex determination in humans? How is it different from birds?
iii. Why can't Anita be blamed for not giving birth to a male child?

Draw a well-labelled diagram of an antibody molecule.

Rajesh was doing gel electrophoresis to purify DNA fragments. Given below is the sketch of the observations of the experiment performed by him.

1. At which end he would have loaded the samples and where?
2. Analyse the reason for different positions taken up by the DNA bands.
3. Elaborate the step he would have followed to visualize DNA bands.

Construct and label a transcription unit from which the RNA segment given below has been transcribed. Write the complete name of the enzyme that transcribed this RNA.

Explain pyramid of numbers with the help of an example.

Expand IUD.

Describe any three steps taken up by our Governmentto check population growth rate.

Following the collision of two trains, a large number of passengers are killed. A majority of them are beyond recognition. Authorities want to hand over the dead to their relatives. Name a modem scientific method and write the procedure that would help in the identification of kinship.

With the help of any two suitable examples explain the effect of anthropogenic action on organic evolution.

Explain PCR technique which used to multiply genes.