!! 4.1.2, Cell Division Flashcards
why is it important for the daughter cells, produced during mitosis, to have the same chromosomes as each other
through mitosis
important for processes that require identical cells to be produced
e.g the growth and repair of tissues and asexual reproduction
what are the 3 stages of the cell cycle
initial growth stage
mitosis
cell divides
what cycle do cells use to divide
cell cycle
summary of what happens during the cell cycle
genetic material is doubled
then divided into two identical cells
where are chromosomes housed in eukaryotic cells
in the nucleus
how are chromosomes usually found in body cells
in pairs
and each carries a large number of genes
what happens in the initial growth stage of the cell cycle
extra ribosomes, mitochondria and other sub-cellular structures are produced
the cell’s chromosomes (which are made of DNA) are replicated
now there are two sets of the cell’s chromosomes.
what happens in the 2nd stage of the cell cycle (mitosis)
the two sets of chromosomes are pulled to opposite ends of the cell
then, the nucleus divides into two
what happens in the final stage of the cell cycle
cell divides
and two identical cells are created by the division of the cytoplasm and cell membranes
which processes involve the production of identical daughter cells
asexual reproduction
growth
repair
what would you expect to happen to the reaction rate in yeast if you increase the temperature
rate of respiration would increase as temperature increases
above a certain temperature, the rate would start to decrease
eventually, the reaction stops because enzymes denature at high temperatures
what are stem cells
undifferentiated stem cells that have not yet specialised to perform a specific function
what are 2 places where stem cells can be found
Plant meristems
bone marrow
embryos
where are stem cells found in plants
AMD what can they do
meristem tissue
and can differentiate into all types of plant cells throughout the life of the plant
allows plants to grow for their whole lives.
what are human adult stem cells used to do
they are used to replace dying cells and damaged tissues
and can differentiate into fewer cell types than stem cells in embryos
what do stem cells in embryos do
used to produce all of the cell types that will make up the organism
therefore can differentiate into most cell types
3 uses of stem cells for medical, scientific and commercial purposes
stem cell treatments
plant clones
therapeutic cloning
how can stem cells from plants be used
to quickly and cheaply produce cloned plants
could help to protect rare plant species from extinction
and create large populations of plants with special features
e.g disease resistance
2 diseases that stem cell treatments may be able to cure
and how they work
stem cells may be able to replace damaged cells in the body
e.g stem cells may replace the damaged cells that cause diabetes or paralysis
what is a risk of stem cell transplantation
viral infection
why may some people object to stem cell treatments
the embryo could be a human being
