Cell Cycle- Lecture 5/6 Flashcards
What is the main phase of cell cycle
Interphase
What happens when the chromosome duplicate
The centromere and sister chromatids join together
How long is cell cycle
Less then 24 hours
After zygote divided what happens
Forms embryo
Cell division in Eukaryotic cells
Goes through the cells cycle
Cell division in prokaryotic cells
Binary fission
Explain stem cells
It is unspecialised
Have ability to differentiate into any type of cell
Found in bone marrow ,
Umbilical cord blood ,
Embryos
What happens in interphase
Cells grows
Chromosomes are duplicated with genetic material
What happens in mitosis
Chromosomes copies are separated from each other and moved to end of cell
What is cytokinesis
Cell divides into two daughter cells
Genetically identical to each other and parent cell
Why is mitosis important
Growth
Repair
Asexual reproduction
How many phases in interphase
3 - g1, s ,g2
What happens in g1
Organelles copied and cells grow
Whathappens in s
Semi -conservative
Synthesis of DNA
What happens in g2
Replicated DNA
Divison of cytoplasm
Mitosis
How to remember mitosis
P -prophase
M-metaphase
A-anaphase
T -telophase
PMAT- I prefer milk and tea
What are the check points for
To make sure the process is ok to continue
If it is not ok then will exit cell cycle
Enter G0 phase
How many chromosomes do people have
46
What happens in prophase
Chromosomes condense - shorter and fatter
Nuclear envelope breaks down
What happens in metaphase
Chromosomes each with 2 chromatides and lin in middlem
Check point checks chromosomes are attracted to spindle
What happens in anaphase
Centromeres divide which separates the 2 chromatids
Spindle contracts pulling chromatids to opposite ends
What happens in telophase
Nuclear envelope forms round the set of chromosomes
Length of time in phase formula
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
Mitosis in plant cells
Use meristems - found right on tip of root
Mitotic index formula
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
What is cancer
Mitosis is controlled process
Mutations
Uncontrolled cell division = can lead to tumours and cancers
What is Primary and secondary cancer
Primary = cancer begins
Secondary = where cancer spreads and grows
Named after where they begin
How many tumours are there
2
Wha are the two types of tumour
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
What genes are responsible for cell cycle
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
What is methylation
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
What is hyper methylation
To much methyl
Cause for proteins to be coded
Can lead to uncontrollable growth
Before cell division what dies DNA do
Copies itself
Enzyme that breaks the hydrogen bonds during replication
DNA helicase
Name of enzyme that catalyses the condensation reaction which join the new strands of nucleotides Together
Polymerase
During replication the new strand is made in which direction , 5 prime to what
3 prime , 3
What technique was used to determine the double helical structure if DNA
X- ray crystallography
What is it known as when ch3 molecule if added to DNA
DNA methylation
