Restriction endonucleases are called as molecular scissors. It is because of the special feature of these enzymes to cut at desired sites of DNA in the technique of genetic engineering. These enzymes are found in bacteria and archaea and provide a defense mechanism against invading viruses.

Hence, the correct option is (D).

Collagen is an insoluble fibrous protein found extensively in the connective tissue of skin, tendons, and bone. Collagen accounts for over 30% of the total 144 body proteins of mammals and it is the most abundant animal protein.

Hence, the correct option is (C).

Antibiotics are chemical substances secreted by certain microbes which inhibit the growth and development of other microbes. Most of them are produced by actinomycetes (especially the genus Streptomyces) and filamentous fungi. Some important antibiotics are tetracycline, chloramphenicol, streptomycin, etc.

Hence, the correct option is (C).

for the image to form by objective is at infinity then the object distance must be f = 2 cm

and the final image is formed at focus of eyepiece i.e, f = −3 cm

distance of image from objective lens is 15 − 3 = 12 cm

Hence, the correct option is (A).

A transmission medium is something that can mediate the propagation of signals for the purposes of telecommunication. Signals are typically imposed on a wave of some kind suitable for the chosen medium. For example, data can modulate sound and a transmission medium for sounds may be air, but solids and liquids may also act as the transmission medium.

Hence, the correct option is (D).

Both the statements A and B are correct.

Organisms which can freely interbreed and produce fertile offspring and have similar coded information or blueprint for making these organisms belong to the same species. In biology, a species is one of the basic units of biological classification and a taxonomic rank. It is often defined as a group of individuals that actually or potentially interbreed in nature.

If two plants can reproduce freely with each other and form seeds, they are concluded to belong to same species. Plants belonging to same species have mostly every character common and will be able to reproduce freely with each other to produce new generations.

Hence, the correct option is (A).

The boiling point of a given compound is as follows:

I. Ethylmethylamine - 33 to 34 °C

II. Propylamine - 49 °C

III. Trimethylamine - 2.9 °C

Hence, the correct option is (B).

Only (iii) and (v) options are incorrect because the Electron transport system occurs in the inner mitochondrial membrane and it is the final stage of aerobic respiration. Respiratory quotient is also known as RQ which is determined through this formula i.e. Volume of carbon dioxide produced to the volume of oxygen consumed.

Hence, the correct option is (A).