Human Health and Disease — BIOLOGY STD 12 Science — Question

Match Column I with Column II.

S. No.	Column I	S. No.	Column II
A.	Acrosome	1.	Motility of sperm towards the egg.
B.	Head	2.	Powerhouse of the sperm; contains a number of mitochondria.
C.	Tail	3.	Contains the genetic material.
D.	Middle piece	4.	Contains enzymes to dissolve egg envelopes.

Mention brain capacities of Homo habilis and Neanderthal man.

What is meant by blending inheritance?

How many germ pores are there in the pollen grains of monocots and dicots?

In what way are monocytes a cellular barrier in immunity?

In the year 1963, two enzymes responsible for restricting the growth of bacteriophage in E.coli were isolated. How did the enzymes act to restrict the growth of the bacteriophage?

Why cannot the sewage be let into natural water bodies directly?

OR

Why is sewage treated in STPs before discharge into a natural water body?

Abnormal gene is replaced by normal genes through:

1. Gene therapy
2. Medicines
3. Cloning
4. Radiation

Name the first restriction endonuclease discovered.

Mention any two probable reasons for rapid rise of population in our country from and about 350 million at the time of independence to about one billion by the year 2000.