science skills + cell size and shape Flashcards
independent variable
the thing that you are testing ( the thing u change)
dependent variable
the factor being affected (the thing u measure)
controlled variables
things that are held constant between all experimental samples/groups eg temp
control group
a test that is not exposed to the IV and can be compared to the test groups
diffusion
when molecules move from an area of high concentration to an area of low concentration
why do cells diffuse
cells do this to obtain their nutrients and remove their wastes, this does not require energy
what does diffusion allow cells to do?
allows cell to grow and survive to carry out its daily functions
the rate of diffusion can vary due to a number of factors such as
temperature, surface area, volume of cell, size of molecule moving by diffusion, concentration gradient ( the difference between high and low concentrations)
why do cells need to be small
cells are small in order to increase its diffusion rate of nutrients. this allows it be supplied with its requirements quickly and efficiently
how to caculate the surface area
6 x length x width
how to calculate the volume
length x width x height
does a small SA: V ratio (eg 2:1) mean that the cell has a fast or slow rate of diffusion?
slow
does a large SA:V ratio eg 6:1) mean that the cell has a fast or slow rate of diffusion?
fast
explain how SA:V ratio and the rate of diffusion are all related to cell survival
the smaller the cube the larger the SA:V ratio. A larger ratio means that the cell has a faster rate of diffusiom. This means that the cells will be able to transport materials in and out quickly enough to survive.
do small or larger shapes have a bigger surface area
smaller
