How is DNA organized?
Into condensed units called chromosomes
What are chromosomes made of
DNA and protein
How many chromosomes in each body cell
46
Where is DNA found
In the nuclei of body cells
Why did we cut up and mash the kiwi fruit in the DNA experiment
To break down the cells and the nucleus to release the DNA
Reasons for mitosis
Growth
Replacement of cells OR repair of tissues
Asexual reproduction
Reason for meiosis
To make gametes (sex cells)
Where are gametes made
The ovaries of females and testes of males
Describe the cells produced from mitosis (2 key points)
2 DIPLOID daughter cells
Genetically identical to each other and the parent cell
Describe the cells produced from meiosis (2 key points)
4 HAPLOID daughter cells
Genetically different to each other and the parent cell
Difference between diploid and haploid
Diploid - (normal) number of chromosomes in a body cell
Haploid - HALF the normal chromosome number (e.g sex cells)
How many copies each chromosome do sex cells contain
One
What are genes
Short sections of dna molecules (imagine them as short sections on the chromosome)
Where does fertilisation occur
Oviduct
What causes a tumour
Uncontrollable mitosis
What cell occurs at fertilisation
Zygote (mitosis develops it into an embryo)
What’s the term to describe all the cells at the start of an embryos life that
Unspecialised cells (UNDIFFERENTIATED STEM CELLS)
Where can stem cells be found in adult humans
Bone marrow
Where are stem cells in plants found
Root tips and shoot tips
Stem cells
Unspecialised cells that can develop or differentiate into other types of (specialised) cells
What do scientists use stem cells for
To repair or replace damaged of diseased tissue
Ethical issue with embryonic stem cells
Embryos must be destroyed so therefore you’re destroying a potential human life
What are the benefits of using your own stem cells
No need for tissue typing (matching)
No rejection
No donor required
Pluripotent stem cells
Can develop into almost any type of cell (embryonic stem cells)
