The nucleus of an atom contain protons and neutrons, which make up most of the mass of an atom.
The answer would be 2 and 3 ( 2nd answer choice)
It was used till the 1960s. Hope i helped.
In unicellular organisms such as bacteria, mitosis helps in asexual reproduction as it produces an identical copy of the parent cell. ... In the case of multicellular organisms, mitosis helps in growth and repair by producing more number of identical cells.
