2.3

Question 1

How do cells reproduce?

Answer 1

By division

Question 2

What does cell division provide for?

Answer 2

Tissue development/growth
Tissue renewal/replacement
Tissue regeneration/repair

Question 3

What is the rate of cell division?

Answer 3

There are different rates of cell division depending on the cell

Question 4

How do somatic cells divide?

Answer 4

Through mitosis

Question 5

What are the three phases of the cell cycle?

Answer 5

Interphase, mitosis and cytokinesis

Question 6

Describe interphase

Answer 6

Cell performing normal function
Not actively focused on division
Can be indefinite
Most cells are in interphase

Question 7

What is mitosis?

Answer 7

When identical copies of DNA are generated
Can take 1 to 3 hours

Question 8

What is cytokinesis?

Answer 8

The physical separation into two daughter cells

Question 9

What occurs in the G1 phase of interphase?

Answer 9

Normal cell function
Generation of organelles
Takes 8 to 12 hours

Question 10

What occurs during the S phase of interphase?

Answer 10

Duplication of chromosomes
DNA replication
Synthesis of histones and nuclear proteins
6 to 8 hours

Question 11

What occurs in G2 phase of interphase?

Answer 11

Takes 2 to 5 hours
Final protein synthesis
Centriole replication

Question 12

What occurs in the G0 phase?

Answer 12

Normal self function
Not preparing for division

Question 13

What are the phases of mitosis?

Answer 13

Prophase, metaphase, anaphase, telophase and cytokinesis

Question 14

What occurs an early prophase?

Answer 14

DNA coils/chromatin condenses
Nuclear membrane disappears

Question 15

What occurs in late prophase?

Answer 15

Centrosome’s migrate to opposite sides of the cell

Question 16

What occurs in metaphase?

Answer 16

Chromosomes align in the centre
Attached to microtubules held by centrioles

Question 17

What occurs in anaphase?

Answer 17

Microtubules pull the chromatids away from the centre

Question 18

What occurs in telophase?

Answer 18

Nuclear membranes reform
DNA uncoils

Question 19

What does P 53 do?

Answer 19

Maintains genomic stability
Activate DNA repair
Arrest so growth
Initiates apoptosis
Inhibits angiogenesis
It is the most commonly mutated gene in cancer

Question 20

What are the two types of cell death?

Answer 20

Apoptosis and necrosis

Question 21

What is apoptosis?

Answer 21

Programmed cell death
Suicide by coordinate intercellular processes

Question 22

What is necrosis

Answer 22

Unplanned so death
Homicide by external stresses

Question 23

What are the intrinsic causes of Apoptosis?

Answer 23

Internal DNA damage/cell stress
Mitochondrial mediated (signal binds to mitochondria membrane this disrupt a membrane an apoptotic complex is formed and destroys or organelles

Question 24

What is extrinsic apoptosis?

Answer 24

External signals
Death receptor mediated (via surface of cell membrane)
Activation of soul death Cascade (proteins)

Question 25

What is the process of apoptosis?

Answer 25

A cascade of enzymatic reactions - Cell shrinkage - Nuclear condensation - blebbing (cell membrane fragments) - Phagocytosis (fragments engulfed by phagocytes cleared by macrophages

Question 26

What are the causes of necrosis?

Answer 26

Pathological injury/damage (mechanical, chemical, infection, immune response)

Question 27

What is the process of necrosis?

Answer 27

- Swelling of the cell (organelle swelling, vacuolation, ions + H2O enter the cell) - blebbing (cell fragments) - nuclear shrinkage (condensation of chromatic) - nuclear fragmentations (chromatic disperses into the cytoplasm - cell rupture - inflammation (destructive to surrounding environment

Question 28

What are the four types of necrosis?

Answer 28

Coagulative, liquefactive, caseous and gangrenous

Question 29

What is coagulative necrosis?

Answer 29

Protein desaturation Morphological features maintained (is had if injury affecting the hear or the kidney.

Question 30

What is liquefactive necrosis?

Answer 30

Rapid lysis of cells by lysosomal degradation enzymes Rapid tissue degradation (ischaemic brain injury)

Question 31

What is caseous necrosis?

Answer 31

Coagulative + liquefactive Cottage cheese like (infraction of the kidney)

Question 32

What is Gangrenous necrosis?

Answer 32

Cause by ischaemia (no bloody supply) to large amount of tissue. Wet or dry liquefactive necrosis.