The best material for studying mitosis in the laboratory is
A. Leaf tip
B. Shoot tip
C. Root tip
D. Gamete

Hint:- The division of one cell into two identical daughter cells is described as mitosis. It takes place in several steps, each phase representing a stereotypical series of changes in the content and structure of cells.

Complete answer:
Root tips are the best to study mitosis. It is characteristic of meristematic cells present at the tip of the roots that provide the most suitable and sufficient raw material to study the different mitosis stages. Onion is a monocot plant and is the most commonly used root tip to study mitosis. Monocotyledonous plants possess huge, easily visible chromosomes. Consequently, their root tips are used. The time taken for mitosis varies since it depends on the type of cell and the type of organisms.
At prophase, mitosis starts with the thickening and coiling of the chromosomes. A rounded form, the nucleolus, shrinks, and vanishes. The initiation of the organization of a group of fibers to form a spindle and the dissolution of the nuclear membrane marks the termination of prophase. At metaphase, the chromosomes, all of which is a double structure composed of duplicate chromatids, line up along the cell's midline. Every pair of chromatids divides into two similar chromosomes in anaphase that are pulled by the spindle fibers to the opposite ends of the cell. The chromosomes start decondensing during telophase, the spindle breaks down, and the nuclear membranes as well as nucleoli reform. To form two daughter cells, the cytoplasm of the mother cell divides, each having the same number and type of chromosomes as that of the mother cell. After completion of mitosis, the period, or phase, is called the interphase.
So, the correct answer is Option (C).

Note:- Mitosis and meiosis are the two principal methods of cell division. Mitotic division occurs frequently in somatic cells to provide new cells for growth as well as mitosis and replacement of dead cells and Meiosis is the reductive or meiotic division commonly seen in germ cells during gamete formation.