(a) Name two sexually transmitted diseases.
(b) Why prenatal sex determination is prohibited by law?
(c) What are the different methods of contraception?

Explanation

(a) AIDS, Syphilis.
(b) Surgery can be used to prevent frequent or unwanted pregnancies. However, this method can be used by people for gender-selective abortion as happens in illegal female foeticides. As a result of prenatal gender determination, the child-gender ratio is declining at an alarming rate in our societies.
Therefore, prenatal gender-determination has been prohibited by law.
(c) (i) Creating a mechanical barrier so that the sperms do not reach the egg. This is done with a condom which is worn around the penis or a similar device that is placed in the vagina.
(ii) Changing the hormonal balance of the body so that fertilization cannot occur. This is done with the help of oral contraceptive pills.
(iii) Contraceptive devices like loop or copper-T are placed in the uterus to prevent pregnancy.
(iv) Surgical methods like vasectomy in males and tubectomy in females.