Unit 5 - Growth and development Flashcards
What are the two forms of cells division?
Meiosis and mitosis.
Why does mitosis occur?
For growth, repair and replacing old tissues.
Where does meiosis occur?
ONLY in the testes and ovaries.
What happens to a cell after it splits by meiosis?
It becomes two gametes, each with 23 chromosomes.
What happens when two gametes fuse together?
A zygote is created.
What is a zygote?
this is an embryo before the 8 cell stage.
Gametes only have _____ the normal amount of chromosomes.
Half.
Why do offspring look different?
When the gametes from father and mother fuse together, for each gene, one of the alleles is passed on. This is either from the mother or father and each child has a different combination of alleles.
How do genes control characteristics?
They dictate which proteins are produced in the cell.
What are the base combinations?
A-T and C-G
What are embryonic stem cells?
These are cells taken from an embryo and are completely unspecialised and can grow into any cell.
How is this helpful when treating diseases?
If someone has a faulty organ then a new organ can be grown in a laboratory and transferred into the body.
What are the ethical issues with embryonic stem cells?
The embryo can’t give consent, is it right to breed something to kill it?, and should you start creating “designer babies”
What are cuttings?
Where part of a plant is cut off and because it contains meri-stem cells it can grow roots and leaves and flowers by itself.
