CELL BIOLOGY Flashcards
CELL BIOLOGY
what is a cell?
smallest unit that lives on its own and makes up all living organisms and the tissues of the body
type of organisms: prokrayotic
prokaryote - small and simple e.g bacteria
type of organism: eukaryotic
eukaryote - large and complex e.g animal, plant cells
Plant and animal cells both have …..
cell membrane: controls what goes in and out, holds cell together
cytoplasm: chemical reactions (gel like substance)
nucleus:genetic material->controls cell activity
mitrochondia:aerobic respiration-> glucose and o2 to energy
ribosome:protein synethsis
what are the features of an animal cell?
cell membrane
nucleus
ribosomes
mitochondria
cytoplasm
what are the features of a plant cell? (extra things)
rigid cell wall:strengthens/supports cell, made of cellulose
permanant vacuole:cell sap
chloroplast:photosynthesis -> food, contains chlorophyll (absorb light)
what are the features of a bacteria cell?
cell membrane
cell wall
cytoplasm
plasmids:small rings of DNA
ribosomes
flagella
magnification =
image size/real size
what is the difference between electron and light microscopes?
electron- uses electrons
- higher magnification and
resolution
- small things in detail like
ribosomes
light- uses light
- can see individual cells
microscope PRACTICAL - making the slide
- add a drop of water to a slide
- cut an onion and separate the epidermal tissues using tweezers
- put it on the slide on the water
- add a drop of iodine on it
- add a cover slip on top - try to not get any air bubbles
microscopy PRACTICAL
- clip the slide onto the stage
- select the lowest objective lens
- use the coarse adjustment knob to move the stage up
- look through the eyepiece
- move the stage up/down until its focused
- keep changing the magnification
- draw your observation
what is cell differentiation?
the process where a cell changes to become speciallised for its function
what are examples of speciallised cells?
sperm
nerve
muscle
root hair
pholem/xylem
what is the function of sperm cells? and how?
reproduction- male to female DNA
long tail, streamlined head - help swim to egg
mitochondria - energy
enzymes in head - digest through egg cell membrane
what is the function of nerve cells? and how?
rapid signalling - carry electrical signals
long - cover more distance
branched connections - connect and form network of nerve cells
what is the function of muscle cells? and how?
contraction
long - more space to contract
mitrochondria - energy
what is the function of root hair cells? and how?
absorb water and minerals on surface of plant roots
hairs in soil - stick into soil
big SA - faster absorbtion
what is the function of phloem/xylem cells? and how?
transport food and water in plants
long (joined end to end)
xylem - hollow
phloem - not many subcellular structures so things can flow easily in/out
what are stem cells?
undifferentiated cells that can differentiate to other cells and be cloned
where are stem cells found?
human embryo
bone marrow - adults only
what can adult stem cells become?
only certain cells like red blood cells
how can stem cells cure disease?
healthy stem cells can be transferred to replace faulty cells
give an example of a stem cell curing disease
embryonic can be made to an insulin-producing cell for people with diabetes OR to nerve cells for paralyzed people
what is embryonic cloning?how does it work?
when an embryo is made to have the same genetic info so the patients body doesnt reject the stem cell
why is medicinal use for stem cells dangerous?
ones grown in labs can become contaminated with a virus which can be passed on
why are people against the use of stem cells?
human embryos shouldnt be used for experiments since each of them are potential human life
where is stem cells found in plants?
meristems
how are stem cells in plants used?
produce clones - fast and cheap
differentiate into any cell
prevent rare plant species from being wipes out
grow plants with desirable features
what is a chromosome
coils of DNA (in nucleus)