biology paper 1 Flashcards
(28 cards)
explain why the potato in the solution decreased in mass
- water moves out of the potato
- by osmosis
- from a dilute to a concentrated solution
- through a partially permiable membrane
explain why the potato in the solution decreased in mass
- water moves — of the potato
- by ——-
- from a dilute to a concentrated solution
- through a ——— permiable membrane
out, osmosis, partially
describe how mitosis produces genetically identical cells
- dna is copied
- all organelles in the cell are copied
- chromosomes are pulled apart to opposite poles
- cytokinesis occurs (cytoplasm and cell membrane divide into 2)
- each cell has the identical dna to the parent cell and to each other
describe how mitosis produces genetically identical cells
- — is copied
- all ———- in the cell are copied
- ———– are pulled apart to opposite poles
- cytokinesis occurs (cytoplasm and cell membrane divide into 2)
- each cell has the ——— dna to the parent cell and to each other
dna, organelles, chromosomes, identical
describe how alveoli and villi are adapted to increase absorption
need adaptation + explanation for level 2
- there are lots of them - giving large surface area to maximise diffusion
- both have thin walls - reducing diffusion distance
- both have good blood supply - maintaning conc gradient
- villi have mitochondria - for respiration
need adaptation + explanation for level 2
describe how alveoli and villi are adapted to increase absorption
- there are lots of them - giving large ——- —- to maximise diffusion
- both have —- walls - reducing ——— distance
- both have good —– supply - maintaning ————- gradient
- villi have mitochondria - for respiration
surface area, thin, diffusion, blood, concentration
explain how a vaccine prevents infection
- dead/weakened pathogen injected
- white blood cells produce antibodies specific to the pathogen
- if then infected white blood cells produce the correct antibodies quickly
- antibodies destroy pathogen
explain how a vaccine prevents infection
- dead/weakened ——– injected
- —– —– —– produce ———- specific to the pathogen
- if then infected white blood cells produce the ——- antibodies ——-
- antibodies destroy pathogen
pathogen, white blood cells, antibodies, correct, quickly
evaluate the use of statins over stents
- statins easy to take but may have side effects
- statins decrease blood cholesterol so slow down the build up of fatty materials, but effects take time to happen
- statins have low cost, but will need to be taken long term
- using a stent holds the artery open for blood to flow but there is a risk of infection during operation
- a stent will remain in place for a long time but there are risks during surgery (heart attack/bleeding)
- having a stent is immediate and recovery is rapid however there is a risk of blood clots
evaluate the use of statins over stents
- ——- easy to take but may have side effects
- statins decrease blood ———- so slow down the build up of —– materials, but effects take time to happen
- statins have low cost, but will need to be taken long term
- using a —– holds the —— open for blood to flow but there is a risk of ——— during operation
- a stent will remain in place for a —- time but there are risks during surgery (heart attack/bleeding)
- having a stent is ——— and recovery is rapid however there is a risk of —– —–
statins, cholesterol, fatty, stent, artery, infection, long, immediate, blood clots
describe the transport of water through a plant from the roots to the atmosphere
- water enters the roots by osmosis
- water transported through the stem in xylem
- water evaporates through stomata
- this process is called transpiration
describe the transport of water through a plant from the roots to the at
- water enters the —– by ——-
- water transported through the stem in —–
- water evaporates through ——-
- this process is called ————-
roots, osmosis, xylem, stomata, transpiration
explain the action of enzymes
- enzyme only binds to one type of substrate because they are complementary (just like a key into a lock)
- this forms an enzyme-substrate complex
- the substrate is broken down into products
- enxyme is unchanged and can catalyse another reaction
explain the action of enzymes
- enzyme only binds to — type of substrate because they are ————- (just like a key into a lock)
- this forms an ————– complex
- the substrate is broken down into products
- enxyme is ——— and can catalyse another reaction
one, complementary, enzyme-substrate, unchanged
describe how the students would find out if the liquid contained glucose
- add benedict’s solution
- boil/heat to 60C or place into a water bath of 60
- colour changes to yellow/orange/green/brown/brick red if glucose is present
describe how the students would find out if the liquid contained glucose
- add ———– solution
- boil/heat to 60C or place into a water bath of 60C
- colour changes to ——/——/—–/—–/—– — if glucose is present
benedict’s, yellow/orange/green/brown/brick red
compare and contrast the structure and function of arteries and veins
- arteries have smaller lumen due to carrying blood at a higher pressure, veins have larger lumen due to carrying blood at low pressure
- arteries carry blood away from the heart, veins carry blood back into the heart
- arteries ahve more muscular and elastic walls to withstand higher pressure, veins are less muscular and elastic
- arteries do not have valves, veins do have valves to prevent backflow of blood
compare and contrast the structure and function of arteries and veins
- ——– have ——- lumen due to carrying blood at a —— pressure, —– have —— lumen due to carrying blood at — pressure
- arteries carry blood —- from the heart, veins carry blood – the heart
- arteries have —- muscular and elastic walls to withstand —— pressure, veins are —- muscular and elastic
- arteries do not have valves, veins do have valves to prevent ——– of blood
arteries, smaller, higher, veins, larger, low, away, to, more, higher, less, backflow
describe the limiting factors of photosynthesis
- carbon dioxide is a reactant that is needed for photosynthesis
- water is a reactant that is needed for photosynthesus
- light availiability provides the energy for photosynthesis
- if the temperature is too low the enzymes needed for photosynthesis work slowly
- if the temperature is too high, the enzymes needed for photosynthesis will be denatured
- chlorophyll is needed to absorb the light for photosynthesis
describe the limiting factors of photosynthesis
- carbon dioxide is a ——- that is needed for photosynthesis
- water is a ——- that is needed for photosynthesis
- —– availiability provides the —— for photosynthesis
- if the temperature is too — the enzymes needed for photosynthesis work ——
- if the temperature is too —-, the enzymes needed for photosynthesis will be ———
- ———- is needed to absorb the —– for photosynthesis
reactant, reactant, light, energy, low, slowly, high, denatured, chlorophyll, light
explain the steps when trialling drugs
pre-clinical trials:
* human cells and tissues in a lab
* live animals test for efficacy, toxicity and the best dosage
clincal trials:
* healthy volunteers to observe side effects
* patients with disease to find optimum dose
* blind trials - patients don’t know if they are recieving a placebo, but dr knows
* double blind trials - patients + doctors dont know if they have the placebo
peer review:
* share results with other scientists before publishing
explain the steps when trialling drugs
pre-clinical trials:
* —– cells and tissues in a lab
* —- ——- test for efficacy, toxicity and the best dosage
clincal trials:
* ——- volunteers to observe —- ——-
* patients with disease to find optimum —-
* —– trials - patients don’t know if they are recieving a placebo, but dr knows
* —— —– trials - patients + doctors dont know if they have the placebo
peer review:
* share results with other scientists before publishing
human, live animals, healthy, side effects, dose, blind, double blind
compare aerobic and anaerobic respiration
- both have glucose as a reactant
- both release energy
- aerobic uses oxygen, anaerobic doesnt
- aerobic produces carbon dioxide and water, anaerobic produces lactic acid
- aerobic releases a larger amount of energy than anaerobic
compare aerobic and anaerobic respiration
- both have ——- as a reactant
- both release ——
- aerobic uses ——, anaerobic doesnt
- aerobic produces carbon dioxide and water, anaerobic produces —— —-
- aerobic releases a —— amount of energy than anaerobic
glucose, energy, oxygen, lactic acid, larger
