human impact on resources peq Flashcards
(23 cards)
describe adv/ disadv of using robes from plant fibres rather than ones made from oil-based plastics
sustainable/ biodegradable/ decomposable
less strong as they can decompose
two aseptic techniques used when working with bacteria
flaming/ disinfecting instruments
keeping lid off for minimum time (petri dish)
work in updraught of a flame
autoclave used plates
disinfect desk before + after use
explain why some bacteria can grow rapidly in skin wounds
warm temperature increases rate of reactions in bacteria/ increases enzyme activity
energy source from tissue/ blood is readily available
water availability for bacterial cell functions
good oxygen availability allowing aerobic respiration
describe clinical trial process after animal testing
applied to healthy humans
one group of patients treated with new antibiotic, others treated with pre-existing treatment
double blind- neither the doctors nor patients know which treatment is being used
participants monitored for side effects/ adverse reactions associated with antibiotic
compare outcomes of patients treated with salve and control group
explain how breeding programmes in zoos maintain genetic diversity of captive populations
animals are selected to prevent breeding between closely related individuals- so they are not vulnerable to inbreeding depression
stud book used to select individuals for mating/ keep record of all breeding events
exchange of animals/ gametes between zoos
explain why healthy volunteers were given different doses of the drug or a placebo
check for side effects
different dose determine safe dose
placebo to make sure that any side effects described were due to the drug
william withering drug testing protocol
digitalis soup
used different doses to determine safe dose
did not use healthy volunteers
did not use placebo
describe how clinical trials of a vaccine would be conducted
small groups of healthy volunteers given vaccine to test for side effects
healthy volunteers tested for presence of antibodies to the virus following vaccination
group of people at risk of contracting the disease are given the vaccine
the number of people who develop the disease post vaccination are monitored
justify the use of a vaccine even though clinical trials had not been completed (for health workers and immediate family of people with disease)
large numbers of people died from disease
health workers in close contact with people suffering from disease
side effects of vaccine will not be worse than contracting disease
vaccinating immediate family will reduce spread of disease
if health workers are vaccinated they could care for more people
suitable conditions for keeping seeds in a food bank
cold and dry
describe how aseptic techniques are used when handling bacterial cultures
working near bunsen burner to provide convection current
sterilising work surface
sterilise/ flame equipment (forceps/ inoculating loop/ bottle neck)
limit time containers are open
explain the role that a placebo and double blind trial have in producing valid conclusions
placebo: provides control group for comparison, ensures the drug is causing the effect
double blind trial: neither doctors nor patients know who has been given actual drug
ensures bias is removed from the trial
devise a procedure that scientists may have used to measure the effects of plant extracts on pathogenic bacteria
seed agar plates with bacteria
add plant extracts to plates on filter paper
use extracts separately and in combination
incubate for 48 hours at 37 ^0C
measure and compare area of zone of inhibition
explain why an agar plate may be incubated at 25 degrees
to allow bacteria to multiply
without encouraging pathogenic organisms
explain adv of drying seeds before storage
extends storage time of the seeds
as drying prevents germination/ decomposition of seeds
explain why bacteria are able to multiply in bloodstream when they enter the body
warm conditions/ water/ glucose available
suitable temperature for bacterial enzymes
glucose used for respiration
explain why the use of bamboo fibres to make coffee cups is sustainable
available to future generations as bamboo is a renewable resource
because more bamboo plants can be grown
describe the roles that zoos play in animal conservation
protect animals from poachers/ hunting
able to provide care/ administering medicine
breeding programmes increase numbers of species- can be released back into wild
improve health of animals- discover better nutrition/ develop a genetic database
two functions of golgi apparatus
modifies proteins
forms vesicles
removes some water from the protein
explain adv of: washing seeds with disinfectant and allowing seeds to dry before putting seeds in a seed bank
washing with disinfectant will kill any microorganisms
drying to reduce chance of germination
therefore preventing any decay/ damage to the seeds
describe structure of starch
starch is a polysaccharide made from alpha glucose
monomers in the chain are joined by 1,4 glycosidic links
starch contains unbranched chains (amylose) and branched chains (amylopectin)
branches are joined to chains by 1,6 glycosidic links
explain why the production of fibres from nettles is more sustainable than fibres produced from crude oil
nettle plants can be regrown- renewable
crude oil is non renewable and will run out
use of fibres from nettles will be available for future generations
clothing made from nettle fibres is biodegradable
describe how a safe dose of a cancer drug could be determined
test drug on animals/ healthy volunteers
then test on group of individuals with cancer
gradually increase dose to determine safe dose
