1 -37 Flashcards
What are stem cells
And where are they found
Undifferentiated cells
Embryos, adult animals and meristems in plants
3 stages of osmosis
- DNA and subcellular structures copied
- chromosomes are pulled to either side of cell and nucleus splits
- cytoplasm and cell membrane divide
what are electron microscopes used for seeing
subcellular structures
what microscope came first
light
how many um are in 1mm
1000
what does um stand for
micro metre
magnification equation
image size over actual size
when do animal cells differentiate
early in life
when do plant cells differentiate
throughout life
what are mesophyll cells specialized for
what do they have alot of
photosynthesis
chloroplasts
what are sperm cells specialized for
what do they have a lot of
energy production
mitochondria
specialized cell def
cell that gained subcellular structures to carry out specific tasks
what 2 things do prokaryotic cells have
cytoplasm and cell membrane
what is genetic material stored on and where is it held
chromosomes and nucleus
what does chlorophyll do
absorb light for photosynthesis
what does the vacuole do
(2)
stores cell sap
gives cell structure
what do cell walls do
give cell sturcture
what takes place in cytoplasm
reactions inside the cell
what does the cell membrane control
movement in and out of the cell
eukaryotic cell e.g
animal and plant
what two things can stem cells found in human embryos do
be cloned
differentiate into any type of human cell
what can stem cells be used to treat (2)
paralysis
diabetes
risks of using stem cells (2)
transfer of bacteria
ethical and religious objections
diffussion def
passive movement of particles from a high concentration to a low
concentration
what factors affect the rate of diffusion
(3)
altering concentration gradient, temperature and
surface area
what 3 things are specialised for exchanging materials
multicellular organisms, surfaces and organ systems
what is the effectiveness of an exchange surface increased by (4)
Having a large surface area
Thin membrane
Efficient blood supply (in animals)
Being ventilated (in animals for gas exchange)
what is osmosis
the passive movement of water from an area of higher water concentration
to an area of lower water concentration, across a partially permeable membrane.
Mass changes are caused by
the movement of water across a plant cell membrane
Active transport uses…
energy from respiration, to transport substances across a membrane from low concentration to high concentration.
what is active transport used in
root hair cells and the small intestine for the absorption of nutrients.
