cell biology Flashcards
what are eukaryotes
organisms made up of eukaryotic cells
what is a prokaryote
a prokaryotic cell (single celled organism)
what are eukaryotic cells
complex and include all animal and plant cells
what are prokaryotic cells
smaller and simpler
what do plant cells have that animal cells dont
cell wall
permanent vacuole
chloroplast
describe structure of bacteria cell
•prokaryotes
•no true nucleus- instead one circular dna strand, floats freely in cytoplasm
•one or more small dna rings called plasmid
•no chloroplast or mitochondria
describe light microscope and what it is used for
use light and lenses
e we can see individual cells and large subcellular structures eg nuclei
describe electron microscope and what it is used for
use electrons rather than light
can see individual organelles eg internal structure of mitochondria and chloroplasts
what is resolution
ability to distinguish
sharper image
formula for magnification
image size/real size
how do you convert from µm to mm
divide by 1000
steps on how to prepare a slide to view an onion cell
- add a drop of water to the middle of a clean slide
- peel epidermal tissue off onion
- place onto water
- drop off iodine solution to stain
- place cover slip on top
- eyepiece
- stage
- coarse adjustment knob
- fine adjustment knob
- objective lense
- stage
what to do once slide is complete
SCLAH
1. select lowest objective lens
2. coarse adjustment knob to move stage just below objective lens
3. look down eyepiece and adjust coarse adjustment
4.adjustment knob to focus
5. higher powered objective lens for better magnification if needed
how is a sperm cell specialised
long tail and streamlined head
lots of mitochondria
enzymes in head to digest egg membrane
how are sperm cells specialised
long tail and streamlined head
mitochondria
enzymes in head to digest egg membrane
how are nerve cells specialised
long to cover distance
branched connections to connect and form a network
how are muscle cells specialised
long for space to contact
mitochondria for energy
how are root hair cells specialised
hair to increase surface area to absorb water and mineral ions from soil
how are phloem cells specialised
form tubes to transport substances around plants
few subcellular structures for flow space
how are xylem cells specialised
tubes to transport
hollow
where do stem cells come from
human embryos or bone marrow
the uses for stem cells
cure disease
produce identical plants
cons of stem cells from human embryos
destroying potential human life
