Cell Biology Flashcards
what is a Prokaryotic cell
a single celled organism which is small and simple e.g bacteria
what is a Eukaryotic cell
organisms which are complex e.g all animal and plant cells
what is a nucleus
contains genetic material which controls the activities of the cell
what is cytoplasm
gel-like substance where most chemical reactions happen and contains enzymes which control these chemical reactions
what is a cell membrane
holds the cell together and controls what goes in and out of the cell
what is mitochondria
these are where most of the reactions for aerobic respiration takes place.
respiration transfers energy that the cell needs to work
what are ribosomes
where proteins are made in the cell
what is a cell wall
only in plant cells
made of cellulose - supports and strengthens the cell
what is a permanent vacuole
only in plant cells
contains cell sap - a weak solution of sugar and salts
what is a chloroplast
only in plant cells
where photosynthesis occurs - makes food for the plant
contains a green substance called chlorophyll which absorbs the light needed for photosynthesis
what is the difference between a plant cell and an animal cell
a plant cell has all of the properties an animal cell does however has a cell wall, permanent vacuole and chloroplasts
what does a bacteria cell contain and how is it different to plant and animal cells
a bacteria cell doesn’t have a nucleus, it has a strand of DNA instead,
they may also contain one or two plasmids which are small rings of DNA
bacteria has a cytoplasm, cell membrane and cell wall but no chloroplasts or mitochondria
what is the difference between a light microscope and an electron microscope
light microscopes use light and lenses to form an image so they let us see individual cells and large subcellular structures
electron microscopes use electrons instead of light to form an image therefore have much higher magnification so a sharper image
what is the formula for magnification
image size/real size
what is differentiation
process by which a cell changes to become specialised for its job
provide some examples of specialised cells
sperm cells are specialised for Reproduction
nerve cells are specialised for rapid signalling
muscle cells are specialised for contraction
root hair cells are specialised for absorbing water and minerals
phloem and xylem cells are specialised for transporting substances
what is a chromosome
contain genetic information
body cells normally have two copies of each chromosome one from the mother and one from the father
what happens in binary fission
the cell splits in two
what are stem cells
stem cells are undifferentiated cells which can be turned into more undifferentiated cells or different types of cells.
give an example of where stem cells can be used
can be turned into insulin producing cells for people with diabetes
what are the two types of stem cells
- extracted from bone marrow - turns into red and white blood cells and platelets
- embryonic stem cells - can be turned into any cell
what is diffusion
particles spread out from an area of high concentration to an area of low concentration
