Chapter 2.6 Cell Division ....

Question 1

What’s mitosis ?

3

Answer 1

Type of nuclear division that produces daughter cells genetically identical to each other and to the parent cell .

Question 2

What’s the order Of the cell cycle starting with M phase ?

Answer 2

1-M phase 
2-G0 phase 
3-G1 phase 
4-Synthesis 
5-G2

Question 3

What happens in M phase ?

3

Answer 3

• cell growth
• PMAT
• Cytokinesis

Question 4

What happens in G0 phase ?

3

Answer 4

Apoptosis
Differentiation
Senscene

Question 5

What happens in G1?

4

Answer 5

• cells growth
• Organelles DUPLICATE
• Biosynthesis
• P53 suppressor ( Tumour suppressor)

Question 6

What happens in synthesis phase ?

2

Answer 6

• DNA Replicates

- Identical sister chromatids

Question 7

What happens in G2 ?

1

Answer 7

GROWTH

Question 8

What are the checkpoints ?

3

Answer 8

1- Metaphase checkpoint
2-G1 checkpoint
3- G2 checkpoint

Question 9

What’s the purpose of the checkpoints?

4

Answer 9

• Prevent uncontrollable division (cancer )
• Detect / repair damage
• ensure cell cycle isn’t reversed
• ensure DNA is duplicate ONCE

Question 10

What does metaphase checkpoint do ?

1

Answer 10

• cell checks that all chromosomes are attached to spindle before mitosis can continue !

Question 11

Why do we need mitosis ?

3

Answer 11

• growth
• tissue repair
• Asexual reproduction ( amoeba , paramecium )

Question 12

What happens in interphase ( mitosis )

3

Answer 12

• cell prepares for cell division
  1-organelles divide
  2-DNA unravels
  3-ATP Content rises

Question 13

What happens in Prophase ( mitosis ) ?

4

Answer 13

• chromosomes shorten and thicken
• Nuclear envelope breaks down
• Centriole divides and moves to opposite end of cells
• Cytoskeleton TUBULIN threads form

Question 14

What happens metaphase ( mitosis ) ?

3

Answer 14

• chromosomes line up
• chromatids attach to spindle
• attached by centromeres

Question 15

What happens in anaphase ?
Chromatids ?
3

Answer 15

1- centromere divides

2-sister chromatically pulled apart by motor protein

Question 16

What happens telophase ?

3

Answer 16

1-separated chromosomes reach opposite poles
2-new nuclear envelope forms
3-cell contains 2 NUCLEI GENETICALLY IDENTICAL TO EACHOTHER

Question 17

What happens in cytokinesis ?
Animal ?
1

Answer 17

• cleavage furrow ( plasma membrane bends inwards )

Question 18

What happens in cytokinesis in plant cells ?

1

Answer 18

End plate ( cellulose forms)

Question 19

What’s meiosis ?

Answer 19

Reduction nuclear division which results in the formation of Gametes ( haploids)

Question 20

What is the importance of meiosis ?

Answer 20

• genetic variation rises
• this increases he chance for survival
• drives evolution

Question 21

Where does meiosis occur ?

Answer 21

Gonads ( ovaries and testes)

Question 22

How does meiosis produce genetic variation ?
When ?
5

Answer 22

1- Crossing over P1
2-Independent assortment ( A1,2)
3-haploid gametes

Question 23

Outline meiosis briefly ?

4

Answer 23

PMAT 1
Interphase
PMAT2
Cytokinesis

Question 24

What plane does the second division ( Prophase 2 ) occur ?

Answer 24

At 90* to P1 division

Question 25

When is the chromosome number halved in meiosis ?

Answer 25

Telophase 1

Question 26

What’s a stem cell ? | 2

Answer 26

Undifferentiated cells which can undergo mitosis to produce specialised cells

Question 27

How does differentiation occur ? | 4

Answer 27

1-some genes are switched off 2-others are expressed more 3-proportion if organelles changes 4-shape change and content change occurs

Question 28

How is a erythrocyte adapted to its function ?

Answer 28

1- bioconcave disk 2-no organelle 3- no nucleus ( packs with more haemaglobin 4-small and flexible

Question 29

How are neutrophils adapted to their function ? | 2

Answer 29

- lysosomes | - cytoskeleton extends ( flexible shape )

Question 30

How is sperm adapted ?

Answer 30

- many mitochondria - acrosomes - flagella - haploid

Question 31

Where in plant do cells differentiate?

Answer 31

Meristem

Question 32

Adaptation of palisade mesophyll cells ? | 2

Answer 32

- many chloroplasts | - thin walls

Question 33

Root hair cell adaptations ? | 4

Answer 33

- large SA - large vacuole - thin permeable walls - extra mitochondria = active transport

Question 34

Guard cells work ? | 4

Answer 34

k+ active transported in Lowers water potential Water moves in Guard cell opens

Question 35

What are the 4 main tissues ?

Answer 35

ECMN - epithelial tissue - connective tissue - Muscle tissue - Nervous tissue

Question 36

What are the two plant tissues? | 2

Answer 36

- epidermal tissue - Vascular tissue - meristematic tissue

Question 37

What are the 3 types of cartilage ? Examples ? (6)

Answer 37

- Hyaline Cartilage ( c shaped trachea ) - Fibrous cartilage (knee joint ) - Elastic cartilage (outer ear )

Question 38

What is cartilage? | Type of tissue ?

Answer 38

Connective tissue

Question 39

How is cartilage formed ?

Answer 39

-chondroblasts secrete extracellular matrix

Question 40

How does Xylem form from meristematic tissue ? | 3

Answer 40

- cambium cells - Xylem vessels - lignin is deposited in cell wall ( waterproof cell and kill it ) - end cell wall breaks down =continuous Column

Question 41

Uses for stem cells ? | 4

Answer 41

- bone marrow transplant - Drug Research - development in biology research - repair of damaged cells / replacement of lost tissue : - alzeihmers - Parkinson’s - type 1 diabetes

Question 42

How does yeast replicate ? | 2

Answer 42

- budding - nucleus divides /mitosis - cell swells in one side - cytoplasm moves into bulge - bulge pinches of