Biotechnology: Principles and Processes — BIOLOGY STD 12 Science — Question

What would happen if histones were to be mutated and made rich in acidic amino acids such as aspartic acid and glutamic acid in place of basic amino acids such as lysine and arginine?

i. Name an ideal pyramid existing in an ecosystem. Construct it up to its three trophic levels along with their
names.
ii. The sun provides 1,000,000 J of sunlight (solar energy) to an ecosystem. Write the amount of energy that is available to the first and third trophic levels, respectively.

Compare in any three ways the chromosomal theory of inheritance as proposed by Sutton and Bovery with that of experimental results on pea plant presented by Mendel.

What is ‘semi-conservative’ DNA replication? How was it experimentally proved and by whom?

Your classmate complains of headache and cough. The doctor confirms that he is suffering from Pneumonia and not common cold, on the basis of certain symptoms. List these symptoms. Mention any two precautions to be followed to prevent the spread of this disease.

What is genetic code? How did genetic code came into existence ?

Correct the following statements:

1. Surgical methods of contraception prevent gamete formation.
2. All sexually transmitted diseases are completely curable.
3. Oral pills are very popular contraceptives among the rural women.
4. In E. T. techniques, embryos are always transferred into the uterus.

During an excavation assignment, scientists collected pollen grains of a plant preserved in deeper layers of soil. Analyse the properties of pollen grains which help in the fossilization.

Briefly give an account of various intra uterine devices. How do they function? What is their advantage?

How do antibiotic-resistance genes function as selectable markers? Explain with the help of E.coli cloning vector pBR 322.