Biology Unit 2: Topic 4 Questions

Front 1

Some metabolic reactions become less efficientin cold weather so the organism generates moreheat to keep warm

Back 1

Physiological

Front 2

Sheep learn to ignore sounds that have noimportance to them

Back 2

Behavioural

Front 3

The ears of African elephants are larger thanthose of Asian elephants, due to differences inthe environment

Back 3

Anatomical

Front 4

Formation of a sun tan when human skin isexposed to sunlight

Back 4

Physiological

Front 5

Suggest how you could investigate the antimicrobial properties of pine needles.

Back 5

1. Filter paper is soaked in extract and pine needles is placed on agar plate.

2. with bacterial

3. Using aseptic conditions, appropriate sealing methods.

4. Left in incubation for 24 hours.

5. Incubate at a temp of 25 c

6. (looking for) {clear area / inhibition zone /loss of cloudiness /reduced cell number/ eq}(around pine needles, extract / filter paper /wells)

7. (clear area ) shows no bacteria

8. Suitable control

Front 6

Name the bond that is broken to convert starch into its monosaccharidebuilding blocks.

Back 6

Glycosidic

Front 7

Name the monosaccharide formed when the bonds in starch are broken.

Back 7

Alpha glucose

Front 8

Suggest why bioplastic is described as a more sustainable form of packagingthan oil-based plastics.

Back 8

1. Bioplastic comes from plants.

2. Plants are renewable.

3. Oil-based plastic is from a non-renewable source.

Front 9

Bioplastic is biodegradable. Suggest one environmental advantage of usingbiodegradable packaging.

Back 9

1. Will not contribute to landfill.

2. Can be decomposed.

Front 10

Suggest why a drug can be tested on rats before testing on humans.

Back 10

1. No harm to human.

2. Rats have similar metabolic rate.

3. Ethical issues.

4. Looking for toxicity effect.

Front 11

State what is done during each of the following phases of testing on humans.

Phase 1

Back 11

Idea of drug tested on {a small number /healthy} individuals

2. ref to low concentration / monitor safety

Front 12

Phase 2

Back 12

1. idea that drug tested on small number ofpatients

2. monitor effectiveness of treatment

Front 13

Describe and explain how this tissue is adapted for the transport of water andsupport in a plant.

Back 13

Water transport:

1. hollow tubes / no living contents / end wallsbroken down 2. idea of allow movement of water e.g.columns of water / vertical movement

3. Waterproof material 4. idea that keeps water in the vessel e.g. lesswater lost

5. (pores / eq} 6. to allow sideways movement of water

SUPPORT

1. Ligin for strength

2. Rings/spirals for strength ad flexibility.

Front 14

Suggest two reasons why the seeds need to be dried and then stored in coldconditions.

Back 14

1. Inhibits germination.

2. Slows down biochemical reactions.

3. Prolongs seed survival.

4. Drying reduces freezing effect.

Front 15

Suggest why seed germination is tested at regular intervals.

Back 15

1. idea that checking {seed viability /germination success

2. allows new seeds to be produced

3. idea that stored seeds may need replacinge.g. due to decay / death

Front 16

Give two ways in which zoos help to conserve endangered species.

Back 16

1. maintaining the endangered species e.g.protection from poachers/ predation

2. (captive) breeding programmes

3. reintroduction into the wild

4. scientific research / example given /

5. education / example given

Front 17

Suggest the form in which the nitrogen was supplied in the watering solution.

Back 17

Nitrate/Ammonia

Front 18

Explain why clear zones are found

Back 18

The substance diffused out

Killed the bacteria.

Front 19

Explain the function of a disc with nothing

Back 19

To act as a control

Front 20

Suggest how you would calculatethe mean diameter of this clear zone.

Back 20

1. Record several measurements

2. Divide by number of measurements to obtain a mean.

Front 21

Suggest one reason why it was good safety practice to incubate the Petri dish at25°C rather than at 37°C.

Back 21

1. 37°C is (human) body temperature

2. (this temp) allows growth of {pathogenic /eq} bacteria / encourages more rapid {growth/reproduction

Front 22

Give the name of one of the other two domains.

Back 22

Bacteria / Eubacteria / Archaebacteria / Archaea

Front 23

Describe the structure of a plant cell wall.

Back 23

1. Cellulose

2. As microfibrils.

3. Held together by hydrogen bonds.

4.

Front 24

Site where there was no cell wall and thecytoplasm linked the two adjacent cells

Back 24

Plasmodesma

Front 25

Dark line that is the boundary between one celland the next cell

Back 25

Middle Lamella

Front 26

Starch is a polymer of one monosaccharide.Name this monosaccharide.

Back 26

Alpha glucose

Front 27

Describe two ways in which the structure of starch is related to its function.

Back 27

1. Made up of many glucose monomers.

2. Energy storage / glucoseis the respiratory substrate

3. Large

4. Insoluble.

5. Compact

6. Can be stored.

7. Branches

8. Increased mobilisation

Front 28

What do low alleles mean?

Back 28

1. Low genetic diversity.

2. Selective advantage/ lack of adaptation.

3. Less likely to survive.

4. More risk at extinction.

Front 29

A female cheetah often mates with several different males and gives birth totwo or three cubs at a time, each having a different father. Suggest why this may be advantageous to cheetahs.

Back 29

1. {greater / eq} genetic diversity (amongst thelitter) /

2. greater chance that will {survive / eq}

3. increased chance of fertilisation / pregnancy/ 4. increase in population size

Front 30

Suggest what effect transferring Rafa from one zoo to another had on geneticdiversity in this species.

Back 30

1. increases genetic diversity

2. (because it) allows {outbreeding / mating /eq} with (genetically) different individuals /eq ;3. stop/reduces {inbreeding / mating withparents / siblings}

4. (which) reduces genetic diversity

Front 31

Describe an experiment to find the optimum nitrate ion concentration for thegrowth of wheat seedling roots.

Back 31

1. 3+ sensible nitrate concentrations.]

2. Repeat each concentration.

3. All seedlings, same age, same plant.

4. Solution used should contain other mineral ions.

5. Temperature, light, volume of mineral solution variable kept constant.

6. Measure growth of root to measure otimum rate of nitrate ion concentration.

Front 32

Give one similarity and two differences, other than the use of a placebo, betweenthese two protocols.

Back 32

Similarity:

Extracting drug from plant/try to find a suitable dose/ used patients

Difference 1:

Idea that only contemporary testing will useanimals

2. idea that only contemporary testing will {test onhealthy people / have phase 1}

3. idea that only contemporary testing will payvolunteers

4. idea that only contemporary testing may involvedouble-blind trials

5. idea that only contemporary testing will {usestatistical analysis / reference to phase 3 / uselarge number }

6. idea of more regulation

7. idea of controlling {factors /variables / eq} intested cohort e.g. age, lifestyle

Front 33

Suggest two reasons why it is better to store seeds rather than to store wholeplants.

Back 33

1. take {less / smaller} space

2. can have more individuals

3. reference to {greater / more} genetic variety ;4. idea of less {maintenance / cost}

5. likely to survive longer

6. can freeze seeds

Front 34

Suggest why it is better to store seeds from several individual plants of onespecies rather than seeds from one individual plant.

Back 34

1. Less chance of inbreeding.

2. Maintain genetic diversity.

3. Reduce chance of storing seeds with disease.

Front 35

Suggest how seeds from these Encholirium species may need to be treated toensure their long term survival in a seedbank.

Back 35

1. Drying

2. Sterilisation

3. Low oxygen

4. Absence of light.

5. Low temp

Front 36

Compare the structure of a cellulose molecule with the structure of starch.

Back 36

1. Both made up of glucose.

2. Both have glycosidic bonds

3. Starch is a glucose Cellulose is b glucose.

4. Starch (Amylose + Amylopectin)

5. All monomers are the same orientation in starch. Inverted in cellulose.

6. Straight chain in cellulose. Branched in starch.

Front 37

Explain how the arrangement of cellulose microfibrils contributes to thephysical properties of plant fibres.

Back 37

1.Strength, flexibility

2. Hydrogen bonding/several layers/criss cross links of microfibrils.

Front 38

Give two functions of xylem vessels

Back 38

1. Transport water.

2. Support/stability.

3. Transport of minerals

Front 39

Suggest three factors that would need to be kept constant in thisinvestigation (Tensile strength)

Back 39

1. length (of fibre)

2. diameter (of fibre)

3. temperature

4. fibre came from the same source

5. stored for the same length of time

6. same way of applying the {masses / knots /

7. same humidity

8. water content of fibre / level of drying

Front 40

Describe how the results obtained would be processed to produce a mean.

Back 40

Add sets all together and divide by number of sets.

Front 41

Suggest why a smaller mass would increase accuracy.

Back 41

Smaller percentage error

Front 42

Suggest why the use of oil-based plastic fibres such as nylon, rather thanplant fibres, does not contribute to sustainability.

Back 42

1. oil is a {non-renewable / finite (resource)

2. (plant fibres) can be regrown / replanted / eq(so is sustainable)

3. ref to time scale

Front 43

Describe how zoos use these programmes to help conserve rare species

Back 43

1. to increase numbers/population size

2. to {maintain / increase} genetic diversity/reduce genetic drift /

3. protect from {predators / poachers

Captive Breeding:

1. Selection of mates/records kept (stud books)

2. Inter zoo animal movement

Re-Introduction

1. Raise awareness through education of local population.

2. Select habitat

Front 44

All the seedlings were grown from seeds from the samewheat plant. Suggest why this would improve the validity of the results.

Back 44

Seeds are the same age and are under the same conditions.

Reduced effect of genotype.

Front 45

Suggest two factors, other than the time for growth and the source of theseeds, that should have been kept constant in this investigation.

Back 45

1. volume of solution

2. light

3. temperature

4. concentration of other mineral ions

5. pH

6. initial status of seedlings e.g. height

Front 46

Describe how the bacteria should be added to the Petri dish.

Back 46

1. Aseptic technique, use sterile equipment.

2. Spread bacteria law, spread over agar.

Front 47

Explain why the lid was secured in this way

Back 47

1. Reduces contamination of culture.

2. Allows entry of oxygen eg. aerobic conditions.

3. Reduces growth of harmful bacteria.

Front 48

Suggest why an incubation temperature of 37°C should not be used in aschool or college laboratory.

Back 48

Encourages growth of bacteria that are harmful to humans.

Front 49

Describe and explain why asexual reproduction results in low genetic diversity.

Back 49

1. Less alleles in the gene pool.

2. Asexual reproduction leads to offspring being genetically identical.

3. No recombination of genetic material (no meiosis)

4. Variation is only possible by mutation.

Front 50

The effect of varying nitrate ion concentration on the growth of one plant speciescan be investigated in a laboratory. Describe how this investigation can be carried out to produce reliable results

Back 50

1. 5 different nitrate concentrations.

2. Repeat of each concentration.

3. Measure increase in mass/length/height

4. Use plants that are the same age

5. A biotic factors (Temp, light, water, pH, CO2 concn)

6. Control variable (no nitrate)

Front 51

Explain why his paper was checked by scientists at this stage.

Back 51

Peer review / conclusions drawn from data are { logical /valid / eq } / data are {acceptable / reliable} / check forplagiarism ;

Front 52

Suggest two ways, other than publication in a journal, that scientists can useto present their data to the scientific community.

Back 52

1. (scientific) conference/ poster / presentation/ seminar/ lecture

2. internet / eq, e.g. websites – blogs

3. book / scientific magazine

Front 53

Explain what is meant by the phrase ‘allowed critical evaluation of his data bythe scientific community’ in stage 3.

Back 53

idea of {checking his methods / repeating experiments/ eq} ;2. to collect more data /review his data / test his results/ eq ;3. to see if his results could be replicated / checkreliability of data

Front 54

Explain why it may be better to make packaging from starch rather than fromoil-based products.

Back 54

1. plants can be {re-grown / sustainable / eq} OR starch {renewable / sustainable} oil is { non- sustainable / non-renewable eq}

2. idea of biodegradability ;3. idea of cheapness

Front 55

Suggest why the discs should be sterilised before being soaked in the extract

Back 55

1. So there is no bacteria on them.

2. That could be harmful.

3. Or that could compete with other bacteria.

Front 56

Describe what the seedbank will do with these seeds to ensure the long-termconservation of the species.

Back 56

1. Clean seeds.

2. Dry seeds.

3. Store at low temperatures.

4. idea of regularly testing viability (during storage ofseed)

5. idea of what to do if viability decreases, e.g. if lessthan 75% germinate collect fresh seed for storage

Front 57

Suggest advantages of selecting seeds of different sizes for long-term storage.

Back 57

1. idea of maintaining or increasing {genetic diversity/ size of gene pool / genetic variation} 2. idea of more chance of having beneficial alleles

3. increases chance of future survival {ifenvironment changes / due to higheradaptability

4. less chance of all being susceptible to a disease

Front 58

Explain why placebos are used to test the efficiency of new drug treatments.

Back 58

1. inactive substance / no drug /

2. idea that it is used as a control e.g.comparison with the actual drug

3. idea of psychological effect of takingeither a drug or a placebo

Front 59

Suggest how you would use this apparatus to enable a valid comparison of thetensile strength of fibres from two different plants.

Back 59

1. Control variables: length/age/source

2. Environmental variable: Temperature, humidity.

3. Size of masses used

4. Add masses until fibre breaks.

5. Repeat and find the mean.

6. Take out anomalous result.

7. Safety procedure.

Front 60

Name the three domains.

Back 60

Archaea

Bacteria

Eukarya

Front 61

Explain how organisms can be classified into taxonomic groups.

Back 61

1. Organisms with shared/common characteristics

2. , similarities in DNA,molecular phylogeny, similaries in behaviour.

Front 62

Suggest how Woese’s idea was critically evaluated.

Back 62

1. Peer reviewed.

2. Published in scientific journal.

3. Presented at a scientific conference.

4. Other scientists repeat experiments to test reliability.

Front 63

Suggest how this captive breeding programme in the six zoos ensures thatgenetic diversity is maintained in this species.

Back 63

1. Prevent inbreeding.

2. Select mates.

3. Captive inbreeding will increase population.

4. Studbooks: records of breeding programme.

5. Avoiding genetic drift.

6. Measuring genetic diversity.

7. Exchange animals for breeding.

Front 64

Suggest three factors that could affect the survival chances of black-footedferrets when they are reintroduced to the sites shown on the map.

Back 64

1. Loss of habitat

2. Availability of prey

3. Competition with other species.

4. Predators

5. Disease

Front 65

Describe and explain the procedures that must be followed before these drugscan be tested on patients.

Back 65

1. idea of testing on non-humans e.g. animals,tissue culture ;2. to test for toxicity / eq ;3. idea of testing on healthy volunteers ;4. to test for side effects

Front 66

Explain how a double blind trial is used to test a new drug.

Back 66

1. Idea of tested on two groups ofpatients (with the condition) ;2. reference to use of placebo ;3. (placebo) used as a {control /comparison} with the actual drug ;4. reference to psychological effect ofplacebo / eq ;5. idea that neither testers nor patientsknow if the treatment contains thedrug or not ;6. idea that this removes bias ;7. idea of testing to find out if drug iseffective

Front 67

Describe how you could use the equipment in this experiment to compare thetensile strength of nettle fibres with that of nylon fibres.

Back 67

1. named fibre variable controlled e.g.length, width, mass ;2. environmental variable controlled, e.g.temperature, humidity ;3. named procedural variable controlled, e.g.size of masses used ;4. idea of adding masses until fibre breaks /eq ;5. repeat and find the { mean / average } ;6. reference to action taken in case of{ anomalous result / outlier } ;7. reference to safety procedure

Front 68

Woese suggested that organisms could be placed in taxonomic groups based onmolecular phylogeny. Explain what is meant by this statement.

Back 68

idea that organisms with { specific /particular / shared / common / similar/ eq } { characteristics / features /traits / eq } are placed in a group ;2. idea that taxonomic groups havespecific differences ;3. idea that phylogeny describes{evolutionary / genetic} relationship ;4. idea that molecular phylogeny basedon similarities in { DNA / DNAsequence / proteins