Studied by 22 people
bacteria
what organisms have prokaryotic cells ?
plant, animal, fungal
what organisms have eukaryotic cells ? (give 3 )
small, plasmids contain DNA, no mitochondria, no chloroplasts
what is a property of a prokaryotic cell? (give 4)
nucleus, cytoplasm, cell membrane, mitochondria, ribosomes
properties of an animal cell ? (give 5)
cell well, vacuole, chloroplasts
specific properties of plant cells ? (give 3)
controls activity of the cell (contains genetic material)
What does the nucleus do?
most chemical reactions take place
What does the cytoplasm do?
controls what passes into the cell
what does the cell membrane do ?
releases energy (aerobic respiration)
what does the mitochondria do ?
protein synthesis
what does the ribosomes do ?
strengthens the cell
what does the cell wall do ?
supports the cell
what does the vacuole do ?
absorbs light energy
what does the chloroplasts do ?
place tissue on slide, add stain, fix on cover slip, put slide on stage, focus with low power (then increase to higher power) , draw the cell
write down the method for required practical (microscopy) :
how clear the image is (seeing 2 or more objects as separate things)
what is the resolution of a microscope ? (definition)
basic details of cell structure
What can you see with a light microscope?
passes electron through the specimen
how does an electron microscope work ?
binary fission (asexual reproduction)
how do bacteria reproduce ?
every 20 minutes
how ofter do bacteria multiply ?
nutrients (agar), temperature 25 degrees
what ius needed for bacteria to reproduce ?
sterilize equipment
how do you prevent contamination ? (micro-organisms)
sterilise (agar/petri dish), inoculating loop is passed through flame, the lid of the dish must be quickly removed (prevent micro organisms entering), store up side down (stop condensation dripping on agar)
how do you produce a tissue culture ?
23
how many pairs of chromosomes does a human have ?
in chromosomes
where is dna stored ?
not specialised yet
what are undifferentiated cells ?
specialisation, shape changes, sub cell structure develops
what happens to cells as organisms develop ? (3)
animal
which type of cell differentiates quicker ? (animal or plant)
divide
What do undifferentiated stem cells do to form stem cells ?
embryonic
what type of stem cells can form any type of cell ?
bone marrow
Where can adult stem cells be found?
therapeutic cloning
what type of cloning can be used to gain stem cells ?
replace damaged cells
what is a use of stem cells ?
could be infected with virus
what is a problem with embryonic stem cells ?
meristems
where are stems cells found in plants ?
clone plant, new cell for growth, prevent extinction
what are a use of plant stem cells ? (3)
cell divides, each chromosome copies, cell pulls apart, nucleus divides
what happens in mitosis ? (give 4)
growth, repair, asexual reproduction
why does mitosis occur ? (3)
what are the stages of the cell cycle ? (3)
dna copies , mitosis, each cell grows
outer surface on the plant
What is the epidermis?
main site of photosynthesis
What is the palisade mesophyll?
air space (gas exchange)
What is the spongy mesophyll?
transport water through the plant
what is the xylem ?
transports dissolved substances
What is phloem?
tip of the leaf
what is meristem tissue ?
leaf
Name an organ in a plant ?
osmosis, the root hair cells
how and where does water enter the plant ?
water evaporates, and diffuses from the length (transpiration)
how does the water leave the leaf ? (give the name of this process)
temperature, air flow, light intensity, humidity
what factors effect the rate of transpiration ?
open and close the stomata
what do guard cells do ?
water bends the cells
what causes the guard cells to open ?
the rate water is taken up
how can you measure rate of transpiration ?
movement of substances around the plant
what is translocation ?
phloem
what tissue is adapted for translocation ?
photosynthesis
what is this the equation for : carbon dioxide + water = glucose+ oxygen
sun light
where does energy come from for photosynthesis ?
chlorophyll
what part of the plant traps sunlight ?
light intensity, temperature, carbon dioxide, chlorophyll
name 4 limiting factors in photosynthesis ?
respration, growth
how do plants use glucose ?
starch, cellulose, glycogen, fat in seeds
what is glucose turned into ?
glucose and nitrate ions
how do plants form proteins ?
exothermic
What type of reaction is respiration?
energy
what does respiration release form glocose ?
chemical reaction, movement, maintain body temp
what is energy needed for ? (give 3)
aerobic respiration
glucose + oxygen -> carbon dioxide + water ... is the equation for what ?
glucose is not completely broken, less energy is transferred, have to repay oxygen debt
what happens in anaerobic respiration ?
fermentation
What anaerobic respiration in plants?
lactic acid and ethanol
what is produced in anaerobic respiration ?
sum of all reactions in the body
What is metabolism?
enzymes
what controls the body's reactions ?
conversion of glucose into starch, formation of lipds, form amino acids, breakdown proteins
Name 4 metabolic processes ?
Movement of molecules from high to low concentration
What is diffusion?
digested molecules from small intestine into blood plasma
give an example of diffusion ?
difference in concentration, temperature, surface area
what effects diffusion ?
high surface area increases the rate
what in terms of surface area increases the rate of diffusion ?
water diffuses across a partially permeable membrane
what is osmosis ?
cut potato cylinders, place in different concentrations, remove after 30 minutes (measure the difference in mass change)
describe a method for the osmosis required practical ?
movement of molecules from low to high concentration
what is active transport ?
yes
Does active transport require energy?
mineral ions to be absorbed into roots
what is an example of active transport ?
a group of tissues working together
what are organs ?
digestive system
what is an example of an organ system ?
biological catalyst
what is an enzyme ?
large protein, have an active site, work best at the optimum
name 3 properties of enzymes ?
salivary glands and pancreas
Where is amylase produced?
breaks down starch (into maltose and sugars)
What does amylase do?
Where is protease produced?
stomach, small intestine, pancreas
breaks proteins down into amino acids
what does protease do ?
Pancreas and small intestine
Where is lipase produced?
breaks lipids into fatty acids and glycerol
What does lipase do?
Benedict solution to brick red
name the food test for sugar ?
iodine solution to black
name the food test for starch ?
Biuret test - turns purple if protein is present
What is the food test for protein?
emulsifies fat, neutralises stomach acid. (increases rate)
What does bile do?
liver
where is bile produced ?
put one tube of amylase and one with starch in a water bath at 37 degrees, after 5 mins add the amylase to starch, test the mixture every 30 seconds with iodine, record how long it takes for starch to be digested (repeat at different ph values)
what is the enzyme required practical ? (method)
arteries, veins, capillaries
what are 3 types of blood vessels ?
transport blood from heart to organs (thick walls)
what do arteries do ?
transport from organs to heart (valves prevent back flow)
what do veins do ?
substances made in cells goes into the blood (thin walls)
what do capilaries do ?
pumps blood in the double circulatory system
how does the heart pump blood ?
