B2 - Cell Division Flashcards
What are the 3 phases of the cell cycle and what happens during it?
in eukaryotes
Interphase - the cell grows bigger and replicates its DNA to form 2 copies of each chromosome and forms a ‘x’ shape. It then increases the number of sub-cellular structures e.g. mitochondria
Mitosis - one set of chromosomes is pulled to each end of the dividing cell and the nucleus divides
Cytokinesis - The cytoplasm and the cell membrane divides to form 2 new daughter cells with identical DNA
What is differentiation?
The process stem cells go through to become specialised (cells that have a specific function in the body)
What is a zygote?
When an egg and sperm cell fuse together to create a new cell. It then divides to create an embryo.
What’s the difference between an embryonic and adult stem cell?
An embryonic stem cell is only found in embryos and can differentiate into all human cell types whilst adult stem cells can only differentiate into certain cells and are found in children and adults.
Where are stem cells found in plants
The meristems which are located at the tips and the roots of a plant
Why are there concerns for potentially using embryonic or adult stem cells to treat people?
As embryonic stem cells may cause cancer and adult stem cells may be infected with viruses and trigger an immune response which means the body would reject the new cells.
What is therapeutic cloning?
The use of cloning embryos for medicinal purposes e.g. using a person’s DNA to clone one of their organs for a transplant
Name one difference between animal and plant cells in terms of differentiation?
Animal cells can only differentiate early on in their lives but most plant cells never lose the ability to differentiate. Plant cells can also differentiate again which doesn’t happen in animal cells.
