Correct Answer – Option 3

Increase in temperature is does not refer to behavior of the fruit fly or intensity of light, hence, options 1 and 2 are incorrect.

Mutation is an activity taking place with respect to the cell structure and is not governed by temperature however is influenced by the environment, hence, option 3 is the most appropriate answer.

Correct Answer – Option 4 – The inserted DNA may direct the synthesis of human proteins

The human gene is inserted into a bacterial cell making it a part of the gene of the bacteria. The bacteria will not destroy itself hence cannot destroy the human gene. Hence, option 1 is incorrect.

Embryo cannot be formed by asexual reproduction, which is the mode of reproduction of bacteria. Hence, option 2 is incorrect.

The inserted human DNA does not have full control of the functioning of the cell. Hence, it cannot change the harmful bacteria to harmless one. However it may direct the synthesis of human protein. Hence, option 3 is incorrect and option 4 is the correct answer.

Correct Answer – Option 3

Variation in offspring's occurs due to cross over. This is quite evident in the figure shown above representing "After"

Correct Answer – Option 1 – may result in the production of a defective protein

A gene mutation is a permanent change in the DNA sequence that makes up a gene. Mutations range in size from a single DNA building block (DNA base) to a large segment of a chromosome.

Gene mutation in a human skin cell cannot alter the sequence of sugars in insulin, cannot decrease mutation rate in offspring and cannot alter the rate of all the metabolic processes in humans. Hence, the options 2,3 and 4 are incorrect.

Correct Answer – Option 4 - enzymes

DNA replication occurs with the help of enzymes.

A Scalpel is too large to cut a DNA. Hence, option 1 is incorrect.

Electrophoresis is also not a method that can be used for cutting the DNA. Hence, option 2 is incorrect

Hormones cannot cut the DNA. Hence, option 3 is incorrect.