Human Reproduction — BIOLOGY STD 12 Science — Question

Answer the following questions:
Four children with four different blood groups are born to parents where the mother has blood group ‘A’ and the father has blood group ‘B’. Work out the cross to show the genotypes of the parents and all four children.

Write an article on vaccination and immunization.

1. Name the respective forms in which the malarial parasite gains entry into

1. Human body and
2. Body of female Anopheles.

2. Name the respective hosts and the sites in their body, where the sexual and asexual reproduction of malarial parasite occur.
3. What is meant by:

1. Addiction
2. Dependence with reference to drugs/ alcohol?

What do you mean by ecological pyramid? Describe the pyramid of biomass in grassland with the help of diagram.

Try to trace the various components of human evolution (hint: brain size and function, skeletal structure, dietary preference, etc.)

A youth in his twenties met with an accident and succumbed to the injuries. His parents agreed to donate his organs. So, their:

1. List any two essential clinical steps to be undertaken before any organ transplant.
2. Why is the transplant rejected sometimes?
3. What views would you share with your health club members to promote organ donation?

What are the major features of embryonic development at various months of pregnancy?

Describe the main ideas behind the biological control of pests and diseases.

Match the sex-chromosome complements in Column I with the male/ female organisms in Column II.

S.No	Column I	S.No	Column II
A.	XO	1.	Human male
B.	XX	2.	Male bird
C.	XY	3.	Male grasshopper
D.	ZZ	4.	Female Drosophila
		5.	Female bird