biodiversity and natural resources

Question 1

what is the definition of endemic?

Answer 1

only found in one geographical location

Question 2

what effect does successfully interbreeding have on genetic diversity?

Answer 2

• increases
• because of introduction of new alleles into the population

Question 3

what is the definition of an allele?

Answer 3

different form of a gene

Question 4

what information is needed to compare the biodiversities of 2 woodlands?

Answer 4

• biodiversity measured using a diversity index
• species richness
• genetic diversity of populations
• presence of any endemic species

Question 5

what aseptic techniques should be used when working safely with bacteria?

Answer 5

• flaming instruments
• keeping lids off for minimum time
  *sterilising work surfaces
• working near a bunsen burner

Question 6

why can some bacteria grow rapidly in skin wounds?

Answer 6

• 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

Question 7

how do breeding programmes in zoos maintain genetic diversity of captive populations?

Answer 7

• animals selected to prevent breeding between closely related individuals
• a stud book is used to select individuals for mating
  *exchange of animals between zoos

Question 8

why are healthy volunteers given different doses of the drug or a placebo?

Answer 8

• check for side effects
• different doses to determine safe dose
• placebo to make sure any side effects were due to drug

Question 9

how would clinical trials of a vaccine be conducted?

Answer 9

*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

Question 10

what are suitable conditions for keeping seeds in a seed bank?

Answer 10

cold, dry

Question 11

what role does a placebo have in producing valid conclusions?

Answer 11

• provides a control group for comparison
  *ensuring that drug is causing the effect

Question 12

what role does a double blind trial have in producing valid conclusions?

Answer 12

• neither doctors nor patients know who has been given the acc drug
  *ensures bias has been removed from the trial

Question 13

compare and contrast modern drug testing with William witherings method

Answer 13

• both use diff doses to determine safe dose
• William did not use healthy volunteers
  *William did not use a placebo

Question 14

what is the relationship between the structure and functions of a grana in photosynthesis?

Answer 14

• 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

Question 15

what monomer makes up cellulose?

Answer 15

beta glucose

Question 16

compare and contrast the structure of cellulose and amylopectin

Answer 16

• both polymers of glucose
  *both have 1,4 glycosidic bonds
  *cellulose beta glucose, amylopectin alpha
  *cellulose not branched, amylopectin is

Question 17

what properties can lignin give to cell walls?

Answer 17

strength and waterproofing

Question 18

what is the role of the middle lamella when a plant cell completes mitosis?

Answer 18

• produced between adjacent new cell
• because middle lamella holds cell walls together

Question 19

what are the effects of a shortage of Mg+ on a plant?

Answer 19

• limits production of chlorophyll
• lack of glucose due to less photosynthesis
• leaves may be yellow/ stunted growth

Question 20

why does a sieve tube element not require RER and ribosomes?

Answer 20

• no transcription so no ribosomes needed for translation
• no proteins synthesised to be processed in RER

Question 21

what is the structure of starch?

Answer 21

• 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

Question 22

why must starch be broken down before it can be used by cells of a growing plant?

Answer 22

• produce glucose
• which is used in respiration

Question 23

what is the difference in number of mitochondria in sieve tube elements and companion cell?

Answer 23

• 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

Question 24

what is meant by the term tensile strength?

Answer 24

the pulling force a fibre can withstand before breaking

Question 25

why are captive breeding programmes important for maintaining biodiversity?

Answer 25

* increase population size of species * increase genetic diversity * prevents extinction

Question 26

justify continued funding of seed banks

Answer 26

conserves genetic diversity of crops crops protected from natural disasters crops kept may have traits useful in future eg disease resistance helps ensure future food security

Question 27

what is meant by species richness?

Answer 27

measures number of species in a habitat

Question 28

what is meant by heterozygosity index?

Answer 28

a measure of genetic diversity within a population OR proportion of heterozygous individuals in a population

Question 29

explain how would the index of diversity change if herbicides were sprayed on a lawn?

Answer 29

decrease fewer species present

Question 30

explain why captive breeding programmes are important for maintaining biodiversity

Answer 30

increases population size of species maintains/ increases genetic diversity therefore prevents extinction of species

Question 31

give 2 reasons why snow leopard cubs born in captivity have not been released into the wild

Answer 31

needed for captive breeding programme would be at risk if released not prepared for reintroduction

Question 32

explain why the agar plate was incubated at 25ºC

Answer 32

to allow bac to multiply without encouraging pathogenic organisms

Question 33

explain the advantages of drying seeds before storage

Answer 33

extends storage time of the seeds because drying prevents germination/ decomposition

Question 34

justify the benefits of storing seeds

Answer 34

prevent species from becoming extinct safeguarding genes that may prove useful in the future allow for reintroduction of species

Question 35

explain why bacteria are able to multiply in the bloodstream when they enter the body

Answer 35

warm conditions/ water/ glucose/ amino acids/ ideal pH available suitable temp/ pH for bacterial enzymes glucose used for respiration/ energy amino acids used for growth

Question 36

explain why the use of bamboo fibres to make coffee cups is sustainable

Answer 36

available to future gens renewable resource more bamboo plants can be grown

Question 37

Plant-based products provide a sustainable alternative to oil-based plastics. The tensile strength of plant fibres can be tested using different methods. One method is to attach both ends of a fibre to clamps horizontally and hang increasing numbers of masses until the fibre breaks. A second method is to attach one end of a fibre to a clamp and the other to a forcemeter, pulling on the forcemeter until the fibre breaks. Explain which method will give more accurate results.

Answer 37

second because exact value will be shown on forecemeter first is less accurate cos true value will be between 2 masses

Question 38

which variables need to be controlled when testing the tensile strength of fibres

Answer 38

temp humidity

Question 39

describe how tensile strength of fibres can be measured

Answer 39

tensile strength calculates as a factor of force divided by cross sectional area of fibre add force/ weight/ mass to a fibre measure force/ weight/ mass required to break fibre calculation of cross sectional area

Question 40

explain how the structure and properties of starch are related to its function as a storage molecule

Answer 40

contains glucose needed for respiration/ energy insoluble so has no osmotic effect amylose is coiled making starch compact amylopectin is branched so is rapidly hydrolysed

Question 41

describe the positions in the stem of the tissues that contain lignin

Answer 41

sclerenchyma fibres on the outer side of the vascular bundle xylem vessels on the inside

Question 42

describe the importance of magnesium ions in the production of plant fibres

Answer 42

magnesium is essential to produce chlorophyll chlorophyll is necessary to produce glucose during photosynthesis glucose needed to produce cellulose for the cell walls

Question 43

describe the arrangement of glucose monomers in a cellulose molecule

Answer 43

1,4 glycosidic bonds alternative monomers inverted

Question 44

explain why they are now classed as diff species

Answer 44

no longer able to interbreed to produce fertile offspring because pops have become reproductively isolated

Question 45

to which group do fungi belong

Answer 45

eukaryota

Question 46

describe how the hardy- Weinberg equation can be used to provide evidence for changes in a population

Answer 46

calc allele frequencies regular sampling over a period of time

Question 47

explain how molecular phylogeny can be used to show that 2 pops are reproductively isolated

Answer 47

compare similarities/ diffs in DNA/ proteins compare amino acid sequences more diffs, more likely they are to be reproductively isolated