1 - cell bio whole of topic Flashcards
light microscope
- use light and lenses to form image of subject and magnify it
- see large subcellular structures like nucleui
- easier to transport than an electron microscope
electron microscope
- use electrons instead of light to form image
- higher mag and higher resolution than light microscope
formula for magnification
mag = image/actual
how do you prep a slide in microscopy
- a drop of water to middle of slide
- cut onion an separate into layers - use tweezers to peel of epidermal tissue from bottom of one layer
- put this tissue on water on the slie
- rop iodine solution on it to stain it
- put cover slip on top - sie ways so no air bubbles
how to use a light microscope
- clip slide onto stage
- select lowest objective lens
- use coarse adjustment knob and move stage up below objective lense
- look down eyepiece and use fine adjustment knob to get in focus
whats differentiation
a cell changes to become specialise for its job
specialised sperm cell
- specialised for reproduction
- long tail + stream lined to swim to egg
- lots of mitochonria to give it enegrry
- enzyme in its hea - digest through egg
specialised nerve cell
- specialised for carrying electrical signals from one part of the boy to the other
- long
- cranched connections to reach further
specialised muscle cell
- specialised for muscle contraction
- long
- lots of mitochondria to get energy
specialised root hair cell
- specialised for absorbing water and minerals
- hairs
- larger sa for absorption
why do we need to the cell cycle
for growth, development and repair
2 main stages in the cell cycle
- growth and DNA replication
- mitosis
stage one of cell cycle - growth and DNA replication
- DNA spread into long strings
- increases the amount of sub-cellular structures
- duplicates its DNA - one copy for each new cell - each arm is an exact duplicate of the other
stage two of the cell cycle - mitosis
once duplicated = ready for mitosis
1. chromosome line up in the centre
2. cell fibre pull them apart which go to opposite ends of the cell
3. membranes form around each of these sets of chromosomes which become the nuclei of the 2 new cells
4. lastly the cytoplasm and cell membrane divide
==== 2 identical daughter cells who are clones of their parent
whats binary fission
when a prokaryotic cell wants to reprouce