Question

An example of mitogen is
A. Cytokinin
B. Glucose
C. Glycerol
D. Fructose

Answer 1

Hint: Growth is one of the life processes exhibited by all living beings. Cell division and cell enlargement are the two main aspects of growth. Some chemical messengers secreted by plants promote cell division to facilitate growth.

Complete answer:
Carbohydrate, lipids, proteins, and nucleic acids are the four main categories of the biomolecules present in cells. Glucose and fructose are simple sugars. Glucose is the preferred substrate for cellular respiration to produce energy. Glycerol is a structural component of triacylglycerols which in turn are the simplest lipids.
Plants are multicellular organisms. Cell division in the existing cells gives rise to new cells which in turn replace the old and worn-out cells. The newly formed cells are also responsible for the growth of plant parts.
Substances that promote cell division are called mitogens. They serve as growth-promoting factors and induce the entry of the cells into the cell division. Some of these substances also stimulate the progression of the cells from the one stage of the cell division into the next. The plant growth hormones such as cytokinin serve as growth-promoting factors and therefore, are the examples of mitogen. Cytokinins are synthesized in the root apical meristem of the plants. Xylem transports the cytokinins from the roots to the shoot. Cytokinins in the shoot and root meristem regulate the process of cell division.

So, the correct answer is A. Cytokinins.

Note: Cytokinins are named so because of their ability to promote the process of cytokinesis, the division of the cytoplasm. Cytokinins also promote the differentiation of immature cells into mature and specialized cells. A high ratio of auxin to cytokinin in the tissue culture induces root formation while a low ratio of auxin to cytokinin induces shoot formation.