Human Reproduction — BIOLOGY STD 12 Science — Question

(a) Write the name of primates existing on earth about 15 million years ago. Write its important characteristics also?
(b) (i) From where did the animals similar to human being meet?
(ii) In which sequence were neanderthal, homohabilis and homo erectus evolved on earth?
(iii) When did modern man evolve on this planet?

In one family, the four children each have a different blood group. Their mother has blood group A and their father has blood group B. Work out a cross to explain how it is possible.

Name and describe the steps involved in the technique widely used in forensics that serves as the basis of paternity testing in case of disputes.

What is tRNA? Where does it occur in a cell? Show by diagram the structure of tRNA. Write a note on the activation of amino acids and the involvement of tRNA in it?

What is foetal ejection reflex? Explain how it leads to parturition?

1. Explain the phenomenon of multiple allelism and co-dominance taking ABO blood group as an example,
2. What is the phenotype of the following:

1. I^Ai
2. ii

Write critical notes on the following :
(a) Eutrophication
(b) Biological magnification
(c) Ground water depletion and measures for its replenishment

Answer the following questions:
Explain the role of any two accessory glands in human male reproductive system.

Describe the exponential growth model of a population with diagram and curve.

If a desired gene is identified in an organism for some experiments, explain the process of the following:
i. Cutting this desired gene at specific location.
ii. Synthesis of multiple copies of this desired gene.