Human Health and Disease — BIOLOGY STD 12 Science — Question

How does replication of the long DNA molecule occur? Explain the process.
OR
Explain the process of DNA replication with the help of a replicating fork.

Answer the following questions:
Why is banana called a parthenocarpic fruit? Would you call banana a true fruit? Give reason in support of your answer.

Answer the following questions:
Explain the hormonal regulation of the process of spermatogenesis in humans.

Vicky's mother was using the same mosquito repellent cream from last six years. She was regularly complaining that this cream has no effects on mosquitoes now. Hearing this, Vicky advised his mother to change the cream as regular usage has led the mosquitoes to develop resistance against it. His mother changed the cream and could notice its effect on mosquitoes.

1. Explain how mosquitoes were not affected by the previous cream?
2. On what factors, Darwin's theory was based?
3. Can you relate this incident to Darwin's concept? How?
4. Identify the values shown by Vicky.

Match the codons in Column I with the amino acids in Column II.

S. No.	Column I		Column II
A	UUU	1	Termination
B	AUG	2	Tyrosine
C	UAA	3	Phenylalanine
D	AGU	4	Methionine
E	UAC	5	Serine

Describe the functions of the following:
Epididymis.

Write the full name of the word AIDS. By what name is the virus that causes this disease known? Explain the symptoms and prevention measures of AIDS disease. Draw a labelled diagram of the replication of the AIDS virus.

Explain the different steps in the construction of recombinant DNA.

Study the graph given below and answer the questions that follow:
Name the hormones ‘X’ and ‘Y’.