B2 - Cell division Flashcards
What is a chromosome?
Coiled up lengths of DNA that contain genes.
What steps are involved in the cell cycle?
STEP 1: Cell grows and increases the number of sub-cellular structures like ribosomes and mitochondria.
STEP 2: The DNA replicates to form two copies of each chromosome.
STEP 3: MITOSIS - One set of chromosomes is pulled to each end of the cell and the nucleus divides.
STEP 4: The cytoplasm and cell membrane divide to form two identical cells.
Why do cells divide by mitosis?
For growth and repair.
What is a stem cell?
An undifferentiated cell capable of giving rise to more cells of the same type.
What can stem cells be used to treat?
Diabetes and paralysis.
What can stem cells from human embryos be turned into?
Any kind of cell because they haven’t become specialised yet.
Where are stem cells found in adults?
Bone marrow
Why are bone marrow stem cells not as good as embryo stem cells?
They can’t turn into any type of cell, only certain ones like blood cells.
What is therapeutic cloning?
A procedure where an embryo is produced with the same genes as the patient.
Why is therapeutic cloning advantageous?
Any cells produced by it, wouldn’t be rejected by the patient because it contains their own genes.
What are the risks associated with stem cells?
If they are contaminated, viral infections may transfer to the patient.
Why are some people opposed to using stem cells from embryos?
They have ethical or religious objections about destroying a potential human life.
What can stem cells from meristems be used for?
To protect rare species from extinction and to produce crops with disease resistance.
