Why is mitosis called equational division?
Mitosis is called equational division because the number of chromosomes in the parent and progeny cells is the same. The chromosome number of the parent is conserved in the daughter cells.
Mitosis usually results in the production of diploid daughter cells with identical genetic complement. Since there is no reduction in chromosome number and the genetic material is equally distributed, it is termed equational division.
Explanation
The textbook explicitly states in section 10.2 M Phase that 'Since the number of chromosomes in the parent and progeny cells is the same, it is also called as equational division.' Additionally, it mentions that 'Mitosis thus, is the equational division in which the chromosome number of the parent is conserved in the daughter cell.' This distinguishes mitosis from meiosis, which is called reduction division as it reduces the chromosome number by half.