Chapter 4

Question 1

Binary fission

Answer 1

the methods of cell division used by prokaryotes

Question 2

reasons for cell division

Answer 2

1. Growth and
   development
2. Maintenance
   and repair
3. Reproduction

Question 3

asexual reproduction 

Answer 3

a method
of reproduction that produces
genetically identical cells without
the fusion of gametes (sex cells)

Question 4

Plasmid

Answer 4

a small, circular loop
of DNA that is separate from a
chromosome, typically found
in bacteria

Question 5

Steps of binary fission

Answer 5

D – DNA replication
E – Elongation
S – Septum formation
C – Cell division

Question 6

There are three stages of the eukaryotic cell cycle:

Answer 6

Interphase
Mitosis
Cytokinesis

Question 7

Interphase

Answer 7

the first stage of the
eukaryotic cell cycle which involves
cellular growth and duplication of
chromosomes. Composed of three
phases: G1, S, and G2

Question 8

Mitosis

Answer 8

the second stage of
the eukaryotic cell cycle, which
involves the complete separation
of sister chromatids and nuclei

Question 9

Cytokinesis

Answer 9

the division of the
cytoplasm and formation of two
daughter cells

Question 10

Phases of interphase

Answer 10

G1phase
G0 phase
S phase
G2 phase

Question 11

G1 phase

Answer 11

Cell growth: increasing the volume of its cytosol, synthesising proteins for DNA replication, replicating its organelles.

Question 12

G0 phase

Answer 12

Cells that are not required to replicate rest in the G0 phase. Cells in G0 are either
quiescent or terminally differentiated. While quiescent cells are dormant and have the
ability to re-enter the cell cycle, terminally differentiated cells remain in G0 indefinitely

Question 13

S phase

Answer 13

During the S phase, the cell replicates its DNA turning one chromosome into two
genetically identical sister chromatids.

Question 14

G2 phase

Answer 14

cell continues to grow and prepare
itself for mitosis: increasing the volume of the cytosol, synthesising proteins in preparation for mitosis.

Question 15

Four stages of mitosis

Answer 15

prophase, metaphase, anaphase, and telophase

Question 16

Prophase

Answer 16

Prophase begins with the condensation into distinct chromosomes,
Simultaneously, the centrioles migrate towards
opposite ends (or poles) of the cell, and spindle fibres
begin to form. The nuclear membrane breaks down
and the nucleolus disappears.

Question 17

Metaphase

Answer 17

In metaphase, the spindle fibres fully form and attach
to the centromere of each chromosome. This allows
the spindle fibres to guide the chromosomes towards
the equator of the cell where they line up.

Question 18

Anaphase

Answer 18

The spindle fibres contract, splitting the centromere and
pulling sister chromatids to opposite ends of the cell.

Question 19

Telophase

Answer 19

The chromosomes densely pack together at either
end of the cell, and new nuclear membranes form,
producing two genetically identical nuclei. The spindle fibres disintegrate and the chromosomes decondense.

Question 20

cytokinesis.

Answer 20

In this stage, the cytoplasm divides and the
organelles evenly distribute themselves before separating into two daughter cells.

Question 21

Cytokinesis in animals vs plants

Answer 21

Cleavage furrow vs cell plate

Question 22

Apoptosis

Answer 22

Apoptosis is the natural and controlled death of cells within our body which plays an
important role in our development and day-to-day lives.

Question 23

Mitochondrial pathway

Answer 23

 the
pathway of apoptosis which
is initiated by the detection of
internal cellular damage. Also
known as the intrinsic pathway

Question 24

Death receptor pathway

Answer 24

the
pathway of apoptosis which
is initiated by the reception of
extracellular death signalling
molecules. Also known as the
extrinsic pathway

Question 25

Blebbing

Answer 25

the bulging of the
plasma membrane to form
apoptotic bodies

Question 26

phagocyte a

Answer 26

a cell of the
immune system responsible
for engulfing and destroying
harmful microorganisms and
foreign material

Question 27

stem cell 

Answer 27

undifferentiated
cells with the capability of
differentiating into specialised cells

Question 28

Specialised cells

Answer 28

cells which serve a
unique, particular function

Question 29

Self renewal

Answer 29

Stem cells have the capacity to replicate without disrupting their ability to differentiate
by producing both a differentiated cell and a copy of themselves when they replicate

Question 30

Potency

Answer 30

Stem cells are undifferentiated cells which can give rise to differentiated cells with a
specialised function

Question 31

Totipotent

Answer 31

Stem cells that can differentiate
into any cell type.

Question 32

Pluripotent

Answer 32

Stem cells that can differentiate
into multiple cell types.

Question 33

Multipotent

Answer 33

Stem cells that can differentiate
into a limited number of
specialised cell types belonging to
a specific tissue or organ