other Flashcards
what are the roles of ribosomes?
they are the site of photosynthesis in plant cells
are bacteria unicellular, multicellular or both?
bacteria are unicellular
are fungi unicellular multicellular or both?
both
what is the role of the nucleus
it controls the genetic material (DNA) of the cell, and so controls what the cell does
what is the definition of osmosis?
the net movement of particles from an area of high water potential to an area of low water potential, across a partially permeable membrane.
osmosis refers to the movement of which molecules?
water molecules
what are 4 main factors that affect the rate of diffusion across a membrane?
1- concentration gradient
2- temperature
3- surface area
4- diffusion distance
for animal, plants and bacterial cells, state whether they are prokaryotic or eukaryotic
eukarotic - plants and animals
prokaryotic - bacteria
name 5 sub-cellular structures (organelles) that are found in both animal and plat cells
1- cell membrane
2- ribosomes
3- nucleus
4- mitochondria
5- cytoplasm
what is the definition of diffusion?
the net movement of particles from an area of high concentration to an area of low concentration
name a protoctist that must consume other organisms to get energy
amoeba
when animal cells are placed in pure water they burst, whereas plant cells become turgid. why is this?
plant cells have a strong cell wall made of cellulose, which prevents them from bursting.
are plants multicellular, unicellular or both?
almost all plants are multicellular
what is chlorophyl?
a green pigment within chloroplasts that absorbs sunlight for photosynthesis.
what is the role of the plant cell wall
to give strength and structure to the plant cell, stopping it from bursting and shrinking when water enters/leaves the cell via osmosis
name 6 sub-cellular structures (organelles) that are found in bacteria cells
1- cell wall+cell membrane
2-cytoplasym
3- circular strand of DNA (nucleoid)
4- plasmid
5- ribosome
6- flagellum
if you add sugar and salts to a beaker of water what will happen to the water potential?
the water potential will decrease
cell membranes are said to be partially permeable, what does this mean?
only some types of molecules can pass through the membrane
what is the role of the mitochondria?
they carry out aerobic respiration
what is the cell membrane and what is its role?
the cell membrane is a protective barrier around the outside of the cell. it controls which substances can pass in and out of the cell.
