B2 - Cell Division - Complete Flashcards
What are the stages of the cell cycle?
PMAT - Prophase, Metaphase, Anaphase, Telophase
What is cell division called?
Mitosis
Where are chromosomes found and what do they do?
Chromosomes are found in the nucleus. They carry your genes
How many chromosomes do you have in each nucleus?
46, chromosomes are in pairs
Explain what happens in Prophase
In prophase, the amount of DNA is doubled and amount of microcellular organisms increased
Explain what happens in Metaphase
The chromosomes are lined up in the centre of the cell and the spindles attach
Explain what happens in Anaphase
The spindles pull the chromatids (attached double DNAs) apart into opposite sides of the cell
Explain what happens in Telophase
In telophase, the two separated DNA sets become more separated by a nuclear membrane - creating two separate nuclei inside the cells. The cytoplasm then divides to create two separate cells
Genetically, are the new cells the same or different from their parents in a mitosis division?
Exactly to the same
What are stem cells?
Undifferentiated cells that adapt to whatever the body needs. They are found in embryos
When can plant cells differentiate?
Plant cells can differentiate throughout their lives, unlike animal cells
Why is it difficult to clone animals?
Because their stem cells differentiate early in development, so they have to be harvested early and in significant numbers in order to actually work
Where does mitosis take place predominantly in plants?
The meristems - in the shoots and root tips
What is a zygote?
A fertilised egg that divides and becomes a hollow ball of cells
What could we use stem cells for?
Curing conditions such as paralysis and diabetes
Where can you find stem cells in humans?
In the bone marrow and in embryos
What are stem cells used for in plants?
To produce large numbers of plants quickly and reliably to stop some going extinct and for research, well as for profitable gain as people can clone plants and then sell them
Name 2 problems with stem cells ethnically
Some religions do not allow the tampering with of the human reproduction process, and some feel that the use of aborted embryos is against their human rights as they cannot give permission
What problems are there with stem cells research other than ethnically?
It is currently very slow, difficult and expensive to carry out, as well as hard to control. They might be rejected by the body of the person being treated or if they are taken from an adult they might be infected with a virus from that person
What are scientists trying to do with stem sells in the future to solve the problem of where they come from?
Grow them in labs although so far only a limited amount of types that come from these stem cells have been produced
