BIOLOGY 2 Marks Questions

The group of bacteria found in both the rumen of cattle and sludge of sewage treatment is Methanogen bacteria. Biological methanation occurs naturally in swamps, digestive systems of animals, oil fields and other environments and is already commonly used in sewage water plants and biogas plants.

a. Baculoviruses / Nucleopolyhedrovirus
b. They are considered to be good bio-control agents because these viruses are excellent candidates for species-specific, narrow- spectrum insecticidal applications and show no negative impacts on plants, mammals, birds or even non-target insects and are desirable for integrated pest management.

A. Trophoblast - Gets attached to the endometrium and draws nutritive material secreted by uterine endometrium gland.
B. Inner cell mass - Differentiates as Embryo.

Perisperm is the remnant of nucellus persistent in the mature seeds of some plants e.g., black pepper, beet etc. The endosperm is a nutritive tissue (triploid) present in the albuminous seeds e.g., coconut, cereals, castor etc.

a. DNA molecule
b. mRNA transcript
c. RNA polymers
d. Rho factor

Flocs are masses of bacteria held together by slime and fungal filaments to form mesh like structures. They are formed during the secondary treatment of sewage.
Consume major part of organic matter in the effluent/lower BOD significantly/reduces polluting potential.