Unit 2 - Cells And Control Flashcards
Mitosis occurs in
Body cells only
Examples of when mitosis is needed
Growth
Repair
Mitosis is a type of
Cell division
5 stages of mitosis
IMPAT Interphase Prophase Metaphase Anaphase Telophase
What happens during interphase
DNA copies (chromosome is visible)
What happens in prophase
Each chromosome consists of two chromatids
What happens during metaphase
Nuclear membrane breaks down
Chromosomes line up along middle of cell
What happens during anaphase
Chromatids become chromosomes as they separate and one from each pair is pulled to each pole of the cell
What happens during telophase
Spindle fibres disappear and new nuclear membrane forms around each group of chromosomes
What is it called when the cell splits into 2
Cytokinesis
Why does cancer occur
Uncontrolled mitosis causes tumour
How does cell division occur in animals
Mitosis causes identical cells
These differentiate
Then can become specialised eg nerve cells
How does cell division occur in plants
Mitosis causes new cells
Cells have vacuoles to take in water by osmosis and can elongate
These can then differentiate into specialised cells
They grow and differentiate throughout life
What is a percentile chart
Show typical trend of growth of an organism
When is a percentile chart used
To monitor growth eg of baby
3 types of stem cell
Embryonic
Adult
Meristems
Embryonic cells is
From an embryo Early stage (8cells)
What can embryonic cell be used for
Replace/repair brain cell
Retina cell
Drug testing
Positive of using embryonic cell
Easy to get
Can produce (specialise) into any other cell
Replace faulty cell with good one
Negatives of using embryonic cells
Ethical (alive)
May not stop dividing so cause cancer
What is an adult stem cell
From differentiated tissue, such as skin or bone
What are adult stem cells used for?
Leukaemia treatment
Positives of using adult stem cells
No ethical issue
No rejection to body
Replace faulty cell with good one
Negatives of using adult stem cells
Produce few types of cell
May not stop dividing so cause cancer
What are meristem stem cells
Found in plant cells (roots tips and shoots)
What can meristem stem cells be used for
To produce any kind of plant cell