Cell division is important for reproduction, growth, and repair in organisms. It enables unicellular organisms to reproduce by dividing and multicellular organisms to grow from cuttings. Sexually reproducing organisms also develop from a single fertilized egg through repeated cell division. Cell division distributes genetic material equally and is necessary for development, while its absence would quickly lead to death. Meiosis and genetic recombination through processes like crossing over during meiosis increase genetic variation within populations.

1.  In unicellular organism, cell division
reproduce an entire organism e.g.
amoeba.
 Cell division can produce the progeny
from some multicellular organisms such
as those plants which grow from cutting.

2.  Cell division also enables sexually
reproducing organisms to develop from
a single cell, the fertilized egg or zygote
 Cell division involves in repairing of cells
e.g. bone marrow makes the new blood
cells.

3.  It is important because it distributes the
identical genetical material to daughter
cell.
 With the cell division growth occur
through an increase in volume and
enlargement of the outer membrane.
 Without cell division death will quickly
ensure.

4.  Meiosis provides a part to remain the
chromosomal number constant
generation after generation.
 In asexually reproduced organisms the
variation among off springs occurs
through mutation.

5.  Genetic variation occurs through
meiosis.
 It can produce off-springs very quickly
e.g. prokaryotes.
 Mutation is also present in sexually
reproduced cell.

6. 1. Crossing over
2. Independent assortment of
homologous chromosome
a) Crossing over
 Exchange of genetic material between
non-sister chromatids of a bivalent
during meiosis.

7.  Average of two or three cross over in per
human chromosome takes place.
 It is necessary for normal segregation.
 E.g. reduced levels of crossing over have
been linked to down’s syndrome which is
occurred due to the extra copy of
chromosome 21.

8.  During this, the homologous
chromosomes pairs separate
independently or in a random manner.
 When homologous pairs align at the
metaphase plate, the maternal or
paternal homologue may be oriented
towards either pole.

9.  In humans who have 23 pairs of
chromosomes, the possible
chromosomal combination in the
gametes is staggering, 2²³ or 8,338,608.
 The staggering amount of genetic
variation achieved through meiosis is
important to the long term survival of
specie because it increases genetic
variation within a population.

10.  The process of sexual reproduction brings
about genetic recombination among
members of a population.