B2 Cell Division Flashcards
What are stem cells
A stem cell is an undifferentiated cell which could turn into any cell in an organism
What are the 2 main properties of stem cells
- can divide by mitosis indefinitely
- can differentiate into specialised cells
What are the 2 types of stem cells
Embryonic and adult
What are the features of embryonic stem cells
- early stage of the embryo
- can produce any type of cell
What are the features of adult stem cells
These cells can grow and replace SIMILAR damaged cells ( eg. Blood cells from bone marrow)
What is meristem
This is a type of stem cell in plants that help them differentiate into any type of plant cell thought the plants life ( this Is how they are able to grow after being cut down)
What is theraputic cloning
Producing an embryo with the same genes as a patient
What are the stages of therapeutic cloning
- combining a egg cell without nucleus and nucleus from a patient
- shock to start
- after time an embryo is created
- stem cells are removed from embryo and signalled to create any animal cell
Why does cell division take place
- G rowth
- R epair
- R eplace
What are the 3 stages to the cell cycle
- DNA is replicated
- Mitosis- the nucleus divides
- Cytoplasm and cell membranes divide to from 2 identical cells
What are the stages of mitosis
- DNA replicates so you have 2 copies of
each chromosome. - Pairs of chromosomes start to line up
in the middle of the cell. - Spindle fibres attach to centre of each
pair of chromosomes - 1 copy of each chromosome is pulled
to opposite poles of the cell. - Two new identical daughter cells form
containing the same DNA as the original