2. Cell division is the
process by which a
parent cell divides into
two or more daughter
cells.
Cell division is usually a
small segment of a
larger cell cycle.

3. Cell cycle is the period
from the time a new
cell is produced until
the cell completes
cell division.
Cell cycle starts with
interphase and is
followed by mitosis
and cytokinesis.

6. Interphase accounts for
about 90% of the cell
cycle.
This interphase is
subdivided into three
phases , that is
i) G1 (growth phase 1)
ii) S (synthesis phase)
iii) G2 (growth phase 2)

7. 1. Proteins and new
cytoplasm organelles such
as mitochondria and
chloroplasts are synthesised
during this stage.
2. The metabolic rate of the cell
is high.
3. The chromosomes are not
condensed and appear as
thread –like structure called
chromatin.
Interphase

8. 1. Synthesis of DNA occurs
during S phase.
2. DNA undergoes replication.
3. Each duplicated
chromosome consists of two
identical sister chromatids.
Interphase

9. 1. The cell continues to grow
and remain metabolically
active.
2. The cell accomulate energy
and completes its final
preparation for cell
division.
Interphase

10. Cell division starts with
nuclear division
(karyokinesis) and is
followed by cytoplasm
division (cytokinesis).
Nuclear division can be
divided into two major
parts:
a) mitosis
b) meiosis

11. Is cell division that
produces daughter cells
with the same number of
chromosomes as the
parent cell.
Occurs in:
a) meristems of plants
b) most somatic cells of
animals

12. a) Produces new cells to
replace cells that are worn
out and damaged
b) Produces new cells for
growth and maintenance in
living organisms

13. c) Mitosis is a form of
asexual reproduction for
Amoeba sp. and Hydra sp.
d) Preserves the diploid
chromosome numbers in
somatic cells

14. Mitosis is divided into 4
phases:
a) Prophase
b) Metaphase
c) Anaphase
d) Telophase

16. 1. The chromosomes
condense , become
shorter and thicker ,
become visible clear
under light
microscope.
2. Each chromosome
now consists of pair
of sister chromatids
joined at centromere.

17. 3. Spindle fibre begin to
form.
4. At the end of the
prophase , nucleus
and nuclear membrane
begin to disappear.

19. 1. Metaphase begin when the
centromeres of all the
chrmosomes lined up on
the metaphase plate.
2. The two sister chromatids
are still attached to one
another at the centromere.
3. Metaphase end when the
centromeres divide.

21. 1. During anaphase , the two
sister chromatids of each
chromosomes separate at the
centromere.
2. The two sister chromatids are
pulled apart to the opposite
poles by the shortening of the
spindle fibres.

22. 3. Once separated , the
chromatids are referred to as
daughter chromosomes.
4. At the end of anaphase , the
two poles of the cell have
complete and equivalent sets
of chromosomes.

24. 1. Telophase begin when the sets
of chromosomes reach the
opposite poles of the cells.
2. The chromosomes start to
uncoil and appear as
chromatines and become less
visible under light
microscope..

25. 3. The spindle fibres
begin to disappear.
4. The nuclear
membrane and the
nucleolus reforms in
each nucleus.

26. Cytokinesis is the division of
the cytoplasm occurs towards
the end of the telophase.
Through cytokinesis , the
daughter cells have all the
organelles , nutrients and
other components needed to
survive and maintain
themselves.

28. Actine filaments in the
cytoplasm contracts to
pull a ring of the plasma
membrane inwards ,
forming a groove called
cleavage furrow until the
cell is separated in two
daughter cells.

30. In plant cell , membrane
enclosed vesicles gather at
plant cells equator between
the nuclei.

31. The vesicles fuse to form cell
plate which divide the cell
into two daughter cells.
After cytokinesis , the new cell
enter G1 stage of interphase ,
complete the cell cycle.

33. Is the process of nuclear
division that reduces the
number of chromosomes in
daughter cells to half that of
the parent cell.

34. Meiosis consists of two
separate nuclear divisions:
a) Meiosis I , which consists of
prophase I , metaphase I ,
anaphase I and telophase I
b) Meiosis II , which consists of
prophase II , metaphase II,
anaphase II and telophase II

36. The chromosomes begin to
condense . They become
shorter , thicker and clearly
visible .
Homologous chromosomes
come together to form pairs of
bivalents through synapsis .

37. Each bivalent consists of a
tetrad . A tetrad consists of
two homologous
chromosomes , each of which
is made up of two sister
chromatids .
Non-sister chromatids
exchange segments of DNA in
a process of crossing over .
Crossing over causes new
combination of genes on a
chromosomes .

38. The points at which segments
of chromatids cross over are
called chiasmata .
At the end of Prophase I , the
nucleolus and nuclear
membrane disappear .

39. The two pairs of centrioles
migrate to the opposite
poles of the cell . Each pair
of centrioles acts as a
central point from which
the spindle fibes will radiate.

41. The spindle fibres pull the
tetrads to the middle of the
cell.
Pairs of homologous
chromosomes align
themselves at the metaphase
plate of the cell.

42. One chromosome of each
homologous pair is attached
to fibres from one pole while
its homologue is attached to
fibres from the opposite pole.

44. The spindle fibres pull the
homologous chromosomes
apart from one another and
move them to the opposite
poles of the cell.
Each chromosome still
consists of two sister
chromatids.

45. Each number of the
homologous chromosomes is
attached to spindle fibres.
At the end of anaphase I ,
each pole has only two
chromosomes (each with two
sister chromatids)

47. The chromosomes arrive at
the poles.
Each pole now has haploid
daughter nucleus because it
contains only one set of
chromosomes.
The spindle fibres disappear.

48. The nuclear membrane
reappears to surround
each group of
chromosomes.
The nucleolus then
reappears in each
nucleus .

50. The nuclear membrane
disintegrates.
The spindle fibres re-
form in each daughter
cell .

52. The chromosomes are
positioned randomly at the
metaphase plate with the
sister chromatids of each
chromosome pointing
towards opposite poles.
Each sister chromatids is
attached to the spindle fibres
at the centromere.

54. The centromeres of the sister
chromatids separate .
The sister chromatids of each
chromosome are now
individual chromosomes .
Each individual chromosome
moves towards the opposite
poles of the cell .

56. Finally , the nucleoli and
nuclear membranes re-form .
The spindle fibres break down
Cytokinesis follows and four
haploid daughter cells are
formed. Each haploid cell
contains half the number of
chromosomes and is
genetically different from the
parent diploid cell . These
haploid cells become
gametes.