B2 - Cell Division [double check] Flashcards
What is inside of cells? (down to genetic info.)
Cells ⇾ nucleus ⇾ chromosomes (46!) ⇾ DNA ⇾ genes ⇾ genetic info
What are the 3 stages of the cell cycle?
stage 1 - replication, stage 2 - mitosis, stage 3 - true division
NOT the actual titles for the stages and therefore not to be used in the actual test.
What happens in stage 1 of the cell cycle?
- The cells grow bigger, increase mass and continue as normal.
- They also replicate their DNA to form two copies of each chromosome ready for cell division.
- They also increase the number of sub-cellular structures
What happens during stage 2 (mitosis) of the cell cycle?
One set of chromosomes is pulled to each end of the dividing cell and the nucleus divides.
What happens during stage 3 of the cell cycle?
Cytoplasm and the cell membranes also divide to form 2 identical daughter cells.
What is differentiation?
Cell specialisation (adapting to perform specific functions, etc.)
Differentiated cells come from what?
Stem cells (in animals there are two types -> embryonic and adult)
What can embryonic stem cells differentiate into?
Any type of stem cell.
What can adult stem cells differentiate into?
A limited few (red blood and skin cells).
When are plants able to differentiate?
Throughout life. Every cell can re-differentiate into a different type of a cell. Plants are consistently occuring.
Where are undifferentiated cells formed?
Meristems (stems and roots of the plant).
This means you can clone a plant cutting almost anywhere on the plant.
What are stem cells used for in humans?
Give examples if you can.
Medical treatments.
Examples include…
- Growing new organs
- Treating blood diseases by making healthy cells
- Skin diseases
etc…
This can only be done using embryonic stem cells.
What are some cons of stem cells?
Embryonic:
- Medical trails are new (so not very reputable)
- To harvest embryonic stem cells, you have to destroy an embryo (which there are some ethical/religious concerns with that)
- It’s fairly hard to force stem cells to differentiate into a certain type of cell
- There are concerns they could be cancer causing (due to the rate at which they differentiate)
Adult:
- They could be infected
- If the stem cells aren’t from the patient, they require immunosuppressants.
Where are embryonic stem cells found?
Newborns’ blood & amniotic sac fluid
What is therapeutic cloning?
Taking the person’s own DNA/Stem cells to culture an embryo and harvest those embryonic stem cells for medical treatment (destroying the risk of rejection).
