biodiversity and natural resources Flashcards
what is the definition of endemic?
only found in one geographical location
what effect does successfully interbreeding have on genetic diversity?
- increases
- because of introduction of new alleles into the population
what is the definition of an allele?
different form of a gene
what information is needed to compare the biodiversities of 2 woodlands?
- biodiversity measured using a diversity index
- species richness
- genetic diversity of populations
- presence of any endemic species
what aseptic techniques should be used when working safely with bacteria?
- flaming instruments
- keeping lids off for minimum time
*sterilising work surfaces - working near a bunsen burner
why can some bacteria grow rapidly in skin wounds?
- warm temperature increases rate of reactions in bacteria
*availability of energy source from tissue/ blood - availability of water for bacterial cell funtions
- good oxygen availability for aerobic respiration
how do breeding programmes in zoos maintain genetic diversity of captive populations?
- animals selected to prevent breeding between closely related individuals
- a stud book is used to select individuals for mating
*exchange of animals between zoos
why are healthy volunteers given different doses of the drug or a placebo?
- check for side effects
- different doses to determine safe dose
- placebo to make sure any side effects were due to drug
how would clinical trials of a vaccine be conducted?
*healthy volunteers given vaccine to test for side effects
*tested for presence of antibodies to the virus
*patients given the vaccine
*number of people who develop the virus after vaccination are monitored
what are suitable conditions for keeping seeds in a seed bank?
cold, dry
what role does a placebo have in producing valid conclusions?
- provides a control group for comparison
*ensuring that drug is causing the effect
what role does a double blind trial have in producing valid conclusions?
- neither doctors nor patients know who has been given the acc drug
*ensures bias has been removed from the trial
compare and contrast modern drug testing with William witherings method
- both use diff doses to determine safe dose
- William did not use healthy volunteers
*William did not use a placebo
what is the relationship between the structure and functions of a grana in photosynthesis?
- grana formed from many layers of thylakoid membrane to increase sa
- thylakoid membranes contain chlorophyll to absorb light
- electron carrier molecules in thylakoid membrane involved in ATP production
what monomer makes up cellulose?
beta glucose
compare and contrast the structure of cellulose and amylopectin
- both polymers of glucose
*both have 1,4 glycosidic bonds
*cellulose beta glucose, amylopectin alpha
*cellulose not branched, amylopectin is
what properties can lignin give to cell walls?
strength and waterproofing
what is the role of the middle lamella when a plant cell completes mitosis?
- produced between adjacent new cell
- because middle lamella holds cell walls together
what are the effects of a shortage of Mg+ on a plant?
- limits production of chlorophyll
- lack of glucose due to less photosynthesis
- leaves may be yellow/ stunted growth
why does a sieve tube element not require RER and ribosomes?
- no transcription so no ribosomes needed for translation
- no proteins synthesised to be processed in RER
what is the structure of starch?
- polysaccharide made from alpha glucose
- monomers in the chains joined by 1,4 glycosidic links
- contains amylose and amylopectin
*branches joined to chains by 1,6 glycosidic links
why must starch be broken down before it can be used by cells of a growing plant?
- produce glucose
- which is used in respiration
what is the difference in number of mitochondria in sieve tube elements and companion cell?
- CC has more
- role of ST is to provide channel so cellular contents are kept to a minimum
*ST has limited ability to carry out aerobic respiration
*ATP supplied to ST from CC
what is meant by the term tensile strength?
the pulling force a fibre can withstand before breaking