biology (paper 1)

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 ?