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Unit1-Key area 3- Producing new cells
1-State the function of cell division
2-State the biological name for cell
division
3-State what is the store of
hereditary information?
4-What is meant by “chromosome
complement”?
5-Describe how the daughter cells
compare to the original cell
6-Explain why it is important that the
chromosome complement of daughter
cells in multi-cellular organisms is
maintained
To increase the number of cells in an
organism so that growth and cell
replacement/repair can take place.
Mitosis
Chromosomes, DNA
Number of chromosomes characteristic to a
species, e.g. humans have 46 chromosomes
They have an identical set of chromosomes
which carry the same information as the
original cell.
To obtain two identical sets of chromosomes,
the genetic material contained in a nucleus is
replicated (copied) before mitosis.
If not, cells might die or grow and/or
function abnormally.
1-Chromatids
2-Centromere (Keeps the chromatids
together)
7
8-Recognise the stages of mitosis in
an animal cell
and in a plant cell
1- Duplicated chromosomes get shorter and
fatter. The cell is ready for mitosis.
2- Chromosome are attached to spindle
fibres at the centromere and positioned at
the equator (plane at the centre of the cell).
They can be seen to be made of two
chromatids.
3- Spindle fibres contract, chromatids are
pulled apart towards opposites poles.
4- Two nuclei form at each end of the cell
5- The cytoplasm starts to divide
6- Two daughter cells are formed
Same as above except for 5:
5- New cell wall forms on a plane at the
centre of a cell.
What is meant by a “diploid cell”
Diploid cells have two matching sets of
chromosomes.
Cell culture
1-Why is cell culture done?
2-What is needed for cell culture?
3-Explain how glassware can be
sterilised
4-Explain how hands and surfaces
need to be prepared before an
experiment.
5-Explain how microbes can be
prevented to contaminate an opened
petri dish
6-Explain how the inoculating can be
sterilized?
7-Why are lids held onto inoculated
petri dishes with tape
- Make food & drink (e.g. beer, wine).
- Test antibiotic, vaccines, medicine.
- Aseptic techniques.
- Appropriate medium .
- Control of other factors (e.g. availability of
oxygen, temperature, pH).
Heat glassware in an autoclave (pressure
cooker) to 121oC.
- Hands need to be washed before an
experiment to remove microorganisms from
skin.
- Surfaces are disinfected before and after
experiment to kill microbes on work area.
Hold the lid over an opened petri dish.
Flame the inoculating loop.
To prevent entry OR exit of microbes from
agar.