Microbes in Human Welfare — BIOLOGY STD 12 Science — Question

Name two commonly used bioreactors. State the importance of using a bioreactor.

Suggest the aspects of reproductive health which need to be given special attention in the present scenario.

Put these statements in the proper order, by rearranging the letters, to describe Darwin's theory of natural selection-

1. The end result of organic evolution is many different species, each adapted to specific environments.
2. Many more individuals are produced each generation that can survive and reproduce.
3. Gradually, over long periods of time, a population can become well adapted to a particular environment.
4. There are inheritable variation among the members of a population.
5. Individuals with adaptive characteristics are more likely to be selected to reproduce by the environment.

An orchid plant is growing on the branch of mango tree. How do you describe this interaction between the orchid and the mango tree?

Why all copulations do not lead to fertilisation and pregnancy?

Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes under a microscope, which sample would you carry and why?

Draw a diagram of pollen grain with germ tube and two male gametes.

Certain attributes of innate immunity are given in the table below. Identify A, B, C, D, E and Frespectively in it.

S.No.	Type of barrier	Example of the barrier	Function
(і)	А	B	Prevent microbial growth
(ii)	C	Polymorpho nuclear leucocytes	D
(iii)	Cytokine	E	F

When and where do chorionic villi appear in humans? State their functions.

What was the composition of the primitive atmosphere that favoured abiotic origin of life on earth?