B2 - Cell division Flashcards
What are the 3 stages of the cell cycle
Stage 1 - replication of DNA
Stage 2 - Mitosis (nucleus divides)
Stage 3 - Cells divides in two
What is differentiation
When unspecialised cells become specialised
What is a stem cell
A cell which has not differentiated yet
How are plant cells different from animal cells
Plant cells can differentiate throughout their lives
What are the two different stem cells called
Embryonic stem cells
Adult stem cells
What does an egg and a sperm cell form
A zygote
What is the main source of Adult stem cells
Bone marrow
What is the source of embryonic stem cells
An embryo
Where are undifferentiated stem cells found in plants
Stems and roots
Called meristems
What are the problems with using embroy’s for the stem cells
Ethical issues
slow and diffucult to make
expensive
What are the problems with using adult stem cells
Can only differentiate into a few different types of cells
Painful operation
what is the cell cycle like in an early embryo
very rapid with little time for growth
what happens in mitosis
1 set of chromosomes is pulled to each end of the cell by spindal fibres and the nucleus divides
Why is mitosis important
It helps with growth, repair and development
What is cloning
producing identical offspring
