Body cells may produce additional body cells by means of organisms that reproduce sexually produce gametes by means of the process of
a) mitosis; meiosis
b) meiosis; mitosis
c) mitosis; conjugation
d) meiosis; gametogenesis

The correct answer for the blank is-

A) mitosis; meiosis

Mitosis is a type of cell division in which a parent cell produces two daughter cells with equal number of chromosomes as that of parent cell. It is essential in repair of damaged tissue and growth of living organisms. This is because body cells produce additional body cells with same genetic material.

Meiosis is another type of cell division that is specific to the sexually reproducing organisms. It is a reductional division as the diploid parent cell produces four haploid, reproductive cells ( called gametes such as eggs and sperms). This means that gamete formation in sexually reproducing organisms occurs through meiosis.

Thus, option A) is the right answer.