The human males use a device X made of a very thin rubber sheet as a covering on the male organ to prevent pregnancy. This device traps the gametes Y in it. In order to prevent pregnancy, the human females use a device Z which is a circle of rubber with a metal spring around it. The device Z is put inside the vagina to cover the cervix. It stops Y from going into the uterus.

(a) What is device X ?

(b) What are Y?

(c) Name the device Z.

(d) What is the general name of these methods of birth control (or preventing pregnancy) ?

(e) The use of which contraceptive device, X or Z, can protect the persons from sexually transmitted diseases ?