Fertilisation results immediately in the formation of :

In which one of the following birth control methods, a small portion of oviducts of a woman is removed by surgical operation and the cut ends are ligated ?

One of the following is a surgical method which prevents the sperms from reaching the ovum and pregnancy does not occur. This method is :

Which one of the following best describes the function of the umbilical cord? It :

The sexually transmitted disease which is caused by bacteria is :