Chapter 2: Cell Cycle

Question 1

Chromosome

Answer 1

Structure made up of double stranded DNA that carries the genes

Question 2

Chromatid

Answer 2

One stranded DNA

Question 3

Chromatin

Answer 3

Tangled form of DNA in cell of nucleus that is not dividing

Question 4

Proliferate

Answer 4

Increase in number rapidly.

Question 5

Via what process do Prokaryotes replicate with?

Answer 5

Binary Fission

Question 6

Steps of Binary Fission

Answer 6

1. Chromosomes will uncoil and replicate.
2. The cytoplasm elongates.
3. Cross wall forms and cell pinches into two.
4. Chromosomes will move to each end of cell.
5. Two identical daughter cells are produced.

Question 7

Via what process do Eukaryotes replicate with?

Answer 7

Mitosis which is a part of the Eukaryotic Cell Cycle.

Question 8

G0 Phase

Answer 8

Non-proliferating or resting stage where the cell is not preparing to replicate the DNA and divide.

Question 9

G1 Phase

Answer 9

Cell produces new proteins and organelles, grows and carries out its normal tasks for the body. Phase ends when the DNA begins to replicate.

Question 10

S Phase

Answer 10

Exact duplicates of DNA molecules are formed, resulting in chromosomes with two chromatids.

Question 11

G2 Phase

Answer 11

Preparation for cell division. This phase is a gap phase where cell has its final opportunity to grow before undergoing nuclear and cytoplasmic division.

Question 12

M (Mitosis) Phase

Answer 12

Cell divides into two new daughter cells. Mitosis is the division of the nucleus and is only a small part of the eukaryotic cell cycle. This phase also includes Cytokinesis, where the cytoplasm is divided across the daughter cells.

Question 13

What is Interphase consisted of?

Answer 13

G1, S and G2 phases

Question 14

Prophase

Answer 14

Chromatin condenses and becomes visible, and the nuclear membrane breaks down.

Question 15

Metaphase

Answer 15

Chromosomes with two chromatids line up along the equator and spindle fibres attach to centromere

Question 16

Anaphase

Answer 16

Spindle fibres contract and pull sister chromatids apart to each pole.

Question 17

Telophase

Answer 17

Nuclear membrane starts to form, chromosomes decondense and chromatin unwinds and becomes less visible.

Question 18

Cytokinesis

Answer 18

Plasma membrane around middle the cell forms a cleavage furrow. Cleavage furrow continues to develop until it eventually meets, and cell is then split, with two new daughter cells produced.
In plants a cell plate forms instead of a cleavage furrow which later becomes the cell wall of a plant.

Question 19

APOPTOSIS

Answer 19

Programmed cell death

Question 20

Steps of Apoptosis

Answer 20

1. Cell receives a signal
2. Caspases activated (activate enzymes that break down cellular components)
3. Blebs are developed on the cell’s surface
4. DNA is broken down
5. Apoptotic bodies (debris) forms and is cleaned up via phagocytes called macrophages

Question 21

Tumour suppressor genes

Answer 21

Inhibit cell division when faulty and prevent development of cancerous cells
The common one is p53 which monitors the health of DNA and repairs it

Question 22

Proto-oncogenes

Answer 22

Promote cell growth and regulate apoptosis

Question 23

What happens if they mutate?

Answer 23

They promote uncontrolled growth and decreased apoptosis

Question 24

Stem cells

Answer 24

Stem cells are undifferentiated cells that have the potential to replicate and develop into many different kinds of cells

Question 25

Unipotent cells

Answer 25

Can differentiate into only one cell type

Question 26

Totipotent cells

Answer 26

Able to give rise to all embryonic & adult lineages

Question 27

Pluripotent cells

Answer 27

Able to give rise to many but not all, of the cell types necessary for foetal development

Question 28

Multipotent cells

Answer 28

Multipotent cells: able to give rise to multiple cells within a lineage