Hint: Mitosis is the part of the cell cycle in which the replicated chromosomes are separated into two new nuclei. This cell division gives rise to genetically identical cells having equal numbers of total chromosomes.
Mitosis occurs in different stages followed by cytokinesis at the end. The mother cell is divided into two daughter cells which are genetically identical to each other. The stages that occur during mitosis are prophase, prometaphase, metaphase, anaphase, and telophase. Let us analyze the options to find out the correct option.
Option A: Mitosis occurs in the somatic cells which comprises all the cells of the body except the germ cells which form the gametes which is egg and sperm. All types of cells except those involved in gamete formation are involved in mitosis. Therefore, this is the correct option.
Option B: Gonads produce the germ cells which form the gametes like egg cell and sperm cell. In gonads of the body meiosis occurs as a cell division. Therefore, this is the incorrect option.
Option C: Axillary buds situated near the apical buds have the meiosis occurring inside the buds as it produces gametes. Therefore, this is the incorrect option.
Option D: Cells of mature leaves show mitosis but it not only occurs in leaves cells but all the somatic cells of the body. Therefore, this is the incorrect option.
Hence, the correct answer is option (A)
Note: Before each mitotic division a copy of every chromosome is created which is followed by mitotic division, a complete set of chromosomes is found in the nucleus of each new cell.