Cell Cycle- Lecture 5/6

Question 1

What is the main phase of cell cycle

Answer 1

Interphase

Question 2

What happens when the chromosome duplicate

Answer 2

The centromere and sister chromatids join together

Question 3

How long is cell cycle

Answer 3

Less then 24 hours

Question 4

After zygote divided what happens

Answer 4

Forms embryo

Question 5

Cell division in Eukaryotic cells

Answer 5

Goes through the cells cycle

Question 6

Cell division in prokaryotic cells

Answer 6

Binary fission

Question 7

Explain stem cells

Answer 7

It is unspecialised
Have ability to differentiate into any type of cell
Found in bone marrow ,
Umbilical cord blood ,
Embryos

Question 8

What happens in interphase

Answer 8

Cells grows
Chromosomes are duplicated with genetic material

Question 9

What happens in mitosis

Answer 9

Chromosomes copies are separated from each other and moved to end of cell

Question 10

What is cytokinesis

Answer 10

Cell divides into two daughter cells
Genetically identical to each other and parent cell

Question 11

Why is mitosis important

Answer 11

Growth
Repair
Asexual reproduction

Question 12

How many phases in interphase

Answer 12

3 - g1, s ,g2

Question 13

What happens in g1

Answer 13

Organelles copied and cells grow

Question 14

Whathappens in s

Answer 14

Semi -conservative
Synthesis of DNA

Question 15

What happens in g2

Answer 15

Replicated DNA
Divison of cytoplasm
Mitosis

Question 16

How to remember mitosis

Answer 16

P -prophase
M-metaphase
A-anaphase
T -telophase
PMAT- I prefer milk and tea

Question 17

What are the check points for

Answer 17

To make sure the process is ok to continue
If it is not ok then will exit cell cycle
Enter G0 phase

Question 18

How many chromosomes do people have

Answer 18

46

Question 19

What happens in prophase

Answer 19

Chromosomes condense - shorter and fatter
Nuclear envelope breaks down

Question 20

What happens in metaphase

Answer 20

Chromosomes each with 2 chromatides and lin in middlem
Check point checks chromosomes are attracted to spindle

Question 21

What happens in anaphase

Answer 21

Centromeres divide which separates the 2 chromatids
Spindle contracts pulling chromatids to opposite ends

Question 22

What happens in telophase

Answer 22

Nuclear envelope forms round the set of chromosomes

Question 23

Length of time in phase formula

Answer 23

Observed number of cells at that stage / total number of cell observed x total length of time of cell cycle

Turn into minutes = ans x 60

Question 24

Mitosis in plant cells

Answer 24

Use meristems - found right on tip of root

Question 25

Mitotic index formula

Answer 25

Number of cells in the field of view undergoing cell division / total number of cells in field of view Count it if u see the nucleus

Question 26

What is cancer

Answer 26

Mitosis is controlled process Mutations Uncontrolled cell division = can lead to tumours and cancers

Question 27

What is Primary and secondary cancer

Answer 27

Primary = cancer begins Secondary = where cancer spreads and grows Named after where they begin

Question 28

How many tumours are there

Answer 28

2

Question 29

Wha are the two types of tumour

Answer 29

1.Benign = grows slowly ,usually in membrane Can be removed doesn’t invade other parts of body Can be removed easily 2.Malignant= transfers from one tissue to another in the bloodstream Tumour grows Cancer cells detach and form secondary tumours in other parts of bodY

Question 30

What genes are responsible for cell cycle

Answer 30

Proto - oncogene - stimulate cell division By producing proteins Mutation occurs = gene become overactive - leads to tumour Mutated proto-oncogenes called oncogenes Tumour -suppressor gene - responsible for making proteins involved in slowing cell division - causes them to self destruct Mutation occurs =Gene will inactivate No protein is produced Cells divide uncontrollably

Question 31

What is methylation

Answer 31

Adding methyl Control whether or not gene is transcribed or not- which part of dna is turned into protein and what are made The growth of tumours can be caused by abnormal methylation

Question 32

What is hyper methylation

Answer 32

To much methyl Cause for proteins to be coded Can lead to uncontrollable growth

Question 33

Before cell division what dies DNA do

Answer 33

Copies itself

Question 34

Enzyme that breaks the hydrogen bonds during replication

Answer 34

DNA helicase

Question 35

Name of enzyme that catalyses the condensation reaction which join the new strands of nucleotides Together

Answer 35

Polymerase

Question 36

During replication the new strand is made in which direction , 5 prime to what

Answer 36

3 prime , 3

Question 37

What technique was used to determine the double helical structure if DNA

Answer 37

X- ray crystallography

Question 38

What is it known as when ch3 molecule if added to DNA

Answer 38

DNA methylation