Year 9 Jan Exam Flashcards
What is active transport?
Movement of dissolved molecules in or out of a cell through the cell membrane. From lower to higher concentration
What is osmosis?
Diffusion of water molecules from a dilute solution to a more concentrated solution across selectively permeable membrane
Why does a larger surface area increase the rate of diffusion?
Because there is more space for molecules to diffuse across the membrane
Define diffusion.
The random movement of a substance from a region of high consent ration to a region of low concentration
How do you convert cm to mm?
x10
How do you convert cm to m?
Divide by 1000
How would you convert 30cm to nanometers?
First you divide x10 to get 300mm then x1000 to get 300,000um then x1000 again to get 300,000,000nm
How would you convert 480,000,000nm into cm?
Divide 480,000,000 by 1000 to get 480,000 then divide by 1000 again to get 480 then divide by 10 to get 48
What is a bacteria cell?
Also called prokaryotic. Meaning they DON’T have a nucleus or any other structure which are NOT surrounded by membranes
What is an animal cell?
Also called eukaryotic. Meaning they DO have a nucleus and other structures which ARE surrounded by membranes. Similar to a plant cell
What is a plant cell?
Also called eukaryotic. Meaning they DO have a nucleus and other structures which ARE surrounded by membranes. Similar to a animal cell
How do you work out the actual size, image size and magnification of an object under a microscope or pic of an object under the microscope?
- Measure the scale bar in mm
- Convert to um (x1000)
- Magnification = scale bar image divided by actual scale bar length (written on the scale bar)
What is the equation for working out the magnification size?
I
A x M
What are the properties of light and electronic microscopes?
An electronic microscope has a much higher resolution than a light microscope
What are the uses of light and electronic microscopes?
Light microscopes are used to study living cells and for regular use when relatively low magnification and resolution is enough