Reproductive Health — BIOLOGY STD 12 Science — Question

A tRNA is charged with the amino acid methionine:

1. At what site in the ribosome will the tRNA bind?
2. Give the anticodon of this tRNA.
3. What is the mRNA codon for methionine?
4. Name the enzyme responsible for this binding.

1. What precaution(s) would you recommend to a patient requiring repeated blood transfusion?
2. If the advise is not followed by the patient there is an apprehension that the patient might contract a disease that would destroy the immune system of his/her body.

Explain with the help of schematic diagram only how the immune system would get affected and destroyed.

During the secondary treatment of the primary effluent how does the significant decrease in BOD occur?

OR

During the secondary treatment of the primary effluent how does the significant decrease in BOD occur?

Explain the packaging of DNA helix.

Certain cotton plants are called Bt cotton. Explain.

In medical termination of pregnancy strict conditions are to be followed. Mention few.

A relevant portion of β–chain of haemoglobin of a normal human is given below:

The codon for the sixth amino acid is GAG. The sixth codon GAG mutates to GAA as a result of mutation ‘A’ and into GUG as a result of mutation ‘B’. Haemoglobin structure did not change as a result of mutation ‘A’ whereas haemoglobin structure changed because of mutation ‘B’ leading to sickle shaped RBCs.

Explain giving reasons how could mutation ‘B’ change the haemoglobin structure and not mutation ‘A’.

What are transgenic bacteria? Illustrate using any one example.

Spermatids possess haploid chromosome number. Explain.

Define heliophytes and sciophytes. Name a plant from your locality that is either heliophyte or sciophyte.