mua corrections Flashcards
explain why this solution the biologist used was ice cold
To reduce enzyme activity so enzymes don’t digest the organelles
explain why this solution the biologist used was buffered
to maintain the pH so enzymes don’t denature
explain why this solution the biologist used was isotonic
so the cell doesn’t burst or sink due to osmosis
why do biologists use a blender and filter the mixture after centrifugation
1) blender: to break open cells
2) filter: to get rid of debris
describe how you make a temporary amount for a piece of plant tissue
1) obtain a thin piece of tissue
2) add water
3) add iodine stain
4) lower a coverslip from an angle to avoid/remove air bubbles
how do you know when an image is taken using an electron microscope
1) high resolution
2) internal structure/organelles can be seen
 when the structure of organelles are visible in the photograph the image cannot have been obtained using a light microscope explain why
1) light microscopes have a low resolution
2) this is because they have a too long wavelength
what are 2 advantages of using electron microscopes
1) high resolution
2) can see internal structures

what are two limitations of electron microscopes
1)A vacuum need to be present
2) colour images aren’t produced
mitosis is important in the life of an organism give two reasons why
1) for growth
2) replaced cells or damaged tissue
Why would a biologist choose to examine 200 cells over 20
Data is representative
how do you know when a cell is in prophase
chromosomes are visible
how do you know when a cell is in anaphase
chromosomes are at opposite poles of the cell and are in a V shape
why do you only use the first 5 mm of the tip of an onion root
The most cell division happens at the end of the tip
what is the name given to the division of cytoplasm during mitosis
cytokinesis
