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2007 Biology
Advanced Higher
Finalised Marking Instructions
 Scottish Qualifications Authority 2007 The information in this publication may be reproduced to support SQA qualifications only on a non-commercial basis. If it is to be used for any other purposes written permission must be obtained from the Assessment Materials Team, Dalkeith. Where the publication includes materials from sources other than SQA (secondary copyright), this material should only be reproduced for the purposes of examination or assessment. If it needs to be reproduced for any other purpose it is the centre's responsibility to obtain the necessary copyright clearance. SQA's Assessment Materials Team at Dalkeith may be able to direct you to the secondary sources. These Marking Instructions have been prepared by Examination Teams for use by SQA Appointed Markers when marking External Course Assessments. This publication must not be reproduced for commercial or trade purposes.
2007 Biology Advanced Higher
Marking scheme
Section A

1. C
Advanced

Section B

Question Acceptable
Notes Negates
1 (a) (i) Exotic/alien (species)
Reduction/population change/elimination/extinction of Effect is important here, so not ‘brings disease' or ‘is a predator' or ‘eats loss of biodiversity crops' but ‘introduces disease' is ok. OR Competitive exclusion/take over niche OR Alteration of community structure/habitat change Variable number of trap nights (in each sweep) Data = numbers or population To give a standard/valid/fair/easier way to compare data Not ‘for comparison' − need benefit of comparing this way Identify the change in the trend/capture rates after September = sweep 5 September as the mind changing/significant finding Trend down and up − both quantifications to illustrate Sweeps/months + captures In sweeps 1-4 capture rates reduced from 589 to 2 (per 10 000) trap nights showing population decline In sweeps 5-6 capture rates increased to 15 (per 10 000) trap nights showing population increase (c) trapping successful (capture rate drops) prior to breeding
This links breeding period information to the data on population resurgence OR After breeding begins (in November) population Trap nights are over more weeks in sweeps 5 and 6, so reference to more trap nights may be error Question Acceptable
Notes Negates
Percentage cover values (in Table 2) are equivalent to capture frequencies expressed as percentages Illustrative quantification; eg % predicted captures in ebony (192/524) x 100 = 36.6 = 37%, Percentage cover = 37% 37% of 524 = 194 is ok Larger numbers than expected trapped in weeded forest/ Leucaena forest (both products of human activity) OR correct reference to densities (e) Specific toxicity to target organism/avoiding poisoning
Not ‘harmless' of/nor not harmful to other species) OR Non-persistent/biodegradable/non-biomagnified (f) (Relationship where) one (species/organism) benefits but
the other neither benefits nor loses (= unaffected) (g) Encourage population increase in natural predator/introduce
a predator/other measures to increase death rate or decrease birth rate check baggage etc of visitors/measures to decrease immigration Question Acceptable
Notes Negates
2 (a) Detritivores
(b) Larger detritivores/invertebrates/organisms (get into the
Any 2 from 4 points 7mm bag) break down/fragment litter OR more organisms enter the 7mm bag, so more breakdown occurs Focus is on processes rather than the organisms that get through the mesh Increases surface area for decomposer action OR increased surface area increases rate of decomposition In 7mm bag there is both breakdown and decomposition whereas there is only decomposition in the 1 mm bag In 7mm bag there is both internal and external digestion whereas in the 1 mm bag there is external only (c) Minerals/any specific mineral eg nitrate/phosphate etc
NOT: nitrogen, amino acids, methane OR Carbon dioxide OR Heat (energy) (d) Degradative/heterotrophic succession
3 1 Regulator − maintains constant internal environment
OR Regulator uses homeostatic control 2 Osmoregulator defined as organism able to control 3 Thermoregulator defined as organism able to keep (body) T constant 4 Regulators occupy wider range of habitats 5 (High) energy costs of homeostasis/regulation Illustrations can be physiological or 6 Illustrative comment on osmoregulation habitat range, eg about migration of 7 Illustrative comment on thermoregulation salmon; endothermy Question Acceptable
4 (a) Increased (intensity of) effect as density increased
Must recognise/explain that adult OR The more flatworms there are per sheep, the lower the flatworms are per sheep, ie density and rate of egg production per worm not a number of worms OR Increasing competition for resource where this is described as density dependent (b) Transmission to new host OR as a vector OR dispersal
(c) Host healthy − parasite harmful but not lethal whereas
NOT: the parasite choosing hosts on host unhealthy the parasite may be lethal/bigger infestation the basis of the host health (d) Reasonable management practice eg Vaccination,
NOT: specific to sheep + fluke molluscicide, fluke treatment, crop rotation, treatment of Focus on prevention food/surroundings/animal to kill parasite/isolation etc 5 (a) Kinase phosphorylates/adds phosphate (the Rb protein) 1
which keeps cells out of the cycle/stops regulatory proteins Focus on inhibitory effect switching on division/block regulatory proteins that promote proliferation/keeps the brakes on division 1
(b) Mutations in both alleles/copies (of Rb gene) are needed
for it to affect cell proliferation whereas proto-oncogenes OR Rb protein acts as an inhibitor of/Rb gene inhibits cell proliferation where oncogenes promote OR proto-oncogenes are proliferation genes, Rb genes are anti-proliferation OR Both Rb alleles mutating is recessive effect and proto-oncogene mutation is a dominant Question Acceptable
Notes Negates
6 (a) Prokaryotic:
From prokaryote point of view no nuclear membrane/true nucleus/would have nucleoid no membrane bound organelles no organelles except ribosomes no histones/nucleosomes/chromosomes contain plasmids has wall of peptidoglycan (b) Medium:cytoplasm:vacuole = 1:3:99
(c) Pump moves sodium ions out (of cytoplasm) and brings
potassium in 1
Sodium concentration in cytoplasm(0.6) is higher than the OR Na and K are both higher than medium, so not Possible pump at vacuole:
Na high in vacuole low in cytoplasm, unlike K 1
7 (a) It has charge/there is an electric current through the gel/gel
DNA has negative charge (b) The mutation increases the fragment size from allele B2
B2 fragment is bigger than B1 fragment but allele B2 is not bigger than B1 (both alleles are present because) the digest produced/gel shows two fragment sizes/lengths OR two bands (d) 1, 3 or 6
Question Acceptable
Notes Negates
8 (a) (i) control mechanisms of the cell cycle;
culturing of mammalian cells. near/before the end of G1 assesses size
2. ensures sufficient (mass) to form two daughter cells/to Not at the end of G1
allow cell division/for cycle to proceed 3. checkpoint during G2 controls entry to mitosis 4. DNA replication assessed 5. so each daughter cell receives complete genome/copy 6. mitosis promoting factor/MPF necessary for entry into 7. MPF is a protein (complex) 8. checkpoint during/in metaphase (of mitosis) controls entry to anaphase/cytokinesis/end of mitosis 9. M checkpoint checks chromosome alignment/ensures each daughter cell receives one chromatid from each 10. cells grown under aseptic conditions and one example
11. mammalian cells need growth factors OR complex
12. (provided in medium by) addition of serum/FBS 13. any 2 ‘simple' components from salts, amino acids, vitamins, glucose, water 14. antibiotics added to prevent bacterial growth 15. use of proteolytic enzyme to release cells from source 16. (normal) cells need surface to adhere to/need anchorage (converse for tumour cells) "normal" must be inferred if not stated. 17. cells spread/flatten out (then) 18. mitosis/divide until growth is confluent 19. (normal) cells grow as a monolayer 20. normal cells divide a certain number of times then die 21. tumour/mutated cells used because they are ‘immortal'/unlimited 22. single cells isolated and cultured to give clones/cell 23. application of cell culture: tissue for skin grafts; antibody production; cell lines for research Question Acceptable
Notes Negates
the structure of phospholipids the composition of the plasma membrane functions of membrane proteins 1. diagram or description of head, tail, hydrophobic, Ignore chemical errors at this stage 2. phospholipid has glycerol, 2 fatty acids and phosphate 3. glycerol structure shown correctly or described (carbons 1,2,3, and OH attached) 4. (fatty acids and phosphate joined by) ester bonds to 5. ester bonds shown or described as condensation reaction between -OH of acid and -OH of alcohol (between OHs of glycerol and acidic ends of fatty 6. fatty acids hydrophobic 7. (usually) one saturated one unsaturated 8. choline attached to phosphate 9. phosphate (and choline are) soluble/hydrophilic/polar 10. model of membrane is described as fluid mosaic 11. description or diagram of bilayer showing orientation of phospholipids – hydrophobic (tails) and hydrophilic (heads) labelled 12. proteins shown/described as integral (intrinsic, transmembrane) and peripheral (extrinsic) 13. lipid bilayer held together by hydrophobic interactions 14. presence of cholesterol/cholesterol affects membrane 15. attachment to cytoskeleton 16. attachment to extracellular/matrix proteins 17. junctions between cells/adhesion to each other 18. transport of materials across membrane/into and out of cell or organelles 19. channels/carriers facilitate/speed passively/by diffusion/or concentration gradient idea 20. pumps/sodium-potassium pump for moving ions OR pumps are proteins for active transport 21. membrane-bound 22. receptors for (hydrophilic) cell signals/hormones 23. glycoprotein/or description of structure for cell-cell
Section C: Biotechnology

Question Acceptable
Notes Negates
1 (a) Sterilise air in/equipment/medium
Aseptic transfers (b) (Cold water flowing through it) cools fermenter to keep the
temperature low/constant/regulated OR fermentation/respiration generates heat so cold water is needed Subtilisin/amylase, cellulase, pectinase (polygalacturonase) lactase/B-galactosidase, invertase/sucrase, restriction enzymes 2 1. requires down-stream processing
Separation idea is at two stages; cells Separation of cells to obtain cell free solution
from the medium and, later, pure 2. By flocculation – to precipitate cells product from crude extract OR using (ultra)filtration/centrifugation/pass culture through bed of silica Extraction
of antibiotic from medium 3. In (organic) solvent if soluble OR any one from adsorption/ion exchange/chemical precipitation by addition of compounds/reverse osmosis/dialysis if not solvent-soluble 4 Concentration to obtain crude solute/product by
removal of solvent/liquid 5. Concentration by distillation OR ultrafiltration/membrane filtration OR (vacuum) evaporation 6. Purification: separation by chromatography OR
7. Naming three stages without description
Question Acceptable
Notes Negates
3 (a) Total count − living and dead/all cells included
Viable count – only living cells OR colonies where each has arisen from one living/viable cell comparison needed
(b) Culture B grows rapidly/exponentially to
Comparing trends limit/max/constant. Culture C increases at lower rate and does not reach a maximum. B maximum is at 120 mins and 150 x 106 cells C 30 x 106 cells at 120 mins /140 x 106 at end/220 mins 80min = 50 cells, 100 min = 100 cells so g =20 min = 0.333hr k=0.693/0.333=2.08/2.079/2.1
(indicates population is not growing exponentially so is short of an environmental factor) (d) (CAP/activator protein is activated by cAMP)
Glucose restricts cAMP production. • activated CAP binds (to DNA) cAMP needed for ß-galactosidase • ß-galactosidase gene transcribed production. When glucose is absent, OR CAP therefore exerts positive control cAMP is now able to activate CAP, the gene switch for ß-galactosidase Question Acceptable
Notes Negates
4 (a) Resistance is lost
Tetracycline resistance gene would be disabled bacteria taking up the plasmid would not be resistant (b) These colonies contain the modified plasmids 1
Because they have ampicillin resistance but not tetracycline OR
They grow on plate X but not on plate Y 1
(c) Transfer of nif gene/nitrogenase gene/enhancing nitrogen
Insecticidal plants Frost resistance Transfer of bacterial toxin to protect from insect damage Bovine somatotrophin (BST). Section C: Animal Behaviour

Question Acceptable
Notes Negates
1 (a) Ethogram
(b) Example: pout/grin/fear/begging/excitement
Explanation: relating animal behaviour to human (c) Grooming/sexual presentation/sexual intercourse/
appeasement gesture 2 (a) Black eyebar provokes/has increased attacks per
minute/rate and orange spots a reduction Black eyebar model: attacks increase to 3.6/min (or by 80%) Orange spot model: decreased to 1/min (or by 50%) Neither response showed any delay (latency) With both models, normal level reached in same time (32/33 min) (b) Orange spots alone suggest egg laying, so no threat
OR Retreating male would show this pattern, so no threat (c) Increased reproductive success/more chance of fathering
offspring/greater access to females Question Acceptable
Notes Negates
(d) (Dimorphic because) territorial males different in
appearance from female (Not dimorphic because) non-territorial male resembles female OR Some males resemble females and others don't (e) Genetic influence – fish reared alone still responded to
genetic = innate = instinctive black eyebar model (or male of same species) with attack 1
Environmental/learned influence – fish reared by another species show attack response towards male of foster species Question Acceptable
Notes Negates
3 (a) Improved chances of survival of young
NOT: survival alone or protection NOT: survival of species (b) Mimicry/camouflage/masquerade
NOT: reference to Batesian or Mullerian mimicry (c) Gape acts as sign stimulus (for host to feed young cuckoo)
Releaser causes host to follow fixed action pattern and (feed young cuckoo) (d) (Reciprocal altruism is) providing help to another and being
but in this case there is no repayment to the host Altruism has costs to one that improve survival of another but reciprocal altruism would require both partners to benefit OR Reciprocal altruism has costs to both but here no cost to cuckoo Question Acceptable
Notes Negates
4 1 Define as (rapid) identification/attachment with another
individual/object 2 During narrow time period/in critical period 3 Occurs after birth/hatching 4 Results in following one individual to the exclusion of 5 Is a learning process/not innate/has environmental 6 Difficult to reverse/irreversible 7 Adaptive significance/benefit in terms of protection of 8 Adaptive significance/benefit in terms of sexual Section C: Physiology, Health and Exercise

Question Acceptable
Notes Negates
1 (a) Blood glucose level is higher after fasting/at the start
Comparison between A and B, so need Blood glucose level is elevated throughout the test period/ comparative words NOT: reference to ‘return to normal' For B the BGL rises faster
Maximum value reached later in the test period
Higher maximum value Any
(b) Glucagon leads to a breakdown of glycogen to increase
NOT: implying glucagon is an enzyme Being overweight/obesity Increased sensitivity to insulin NOT: reference to lipid profile increase in the number of (active) insulin receptors (on the increased blood flow to muscle exercise reduces body weight/fat exercise increases metabolism
increase in enzyme activity for glucose storage Any two
2 (a) BMR = 0.062 X 75 + 2.036 = 6.686/6.69/6.7 MJ/day
(b) (In indirect calorimetry oxygen consumption is) used in a
mathematical formula/calculation/work out the energy OR (indirect calorimetry) assumes a relationship between
oxygen consumption and energy expenditure direct calorimetry measures the heat produced Question Acceptable
Notes Negates
(c) 1 Body size/mass/weight – heavier people have a greater
BMR is a measure the energy need of BMR (because they have more tissues) an individual, not per kg tissue. 2 Body composition – the more lean tissue a person has/
Not total energy expenditure, so more muscular the higher the BMR reference to energy costs of activity, pregnancy and climate are additional 3 Age – BMR falls with age
OR children have a higher BMR weight for weight than 4 Sex – BMR higher in males
because they have more lean/muscle tissue/females tend to have more body fat/adipose tissue 5 Nutritional status (diet) – BMR reduced by low energy
intake/fasting/dieting 6 because lean tissue is more active metabolically (per kg) than adipose [applied to either 2, 4 or 5] 7 age effect is due to changing body composition OR due to decrease in activity per kg of body tissue OR due to energy cost of growing/since they are actively 3 (a) (i) (Maximum) oxygen uptake and body mass
Maximum stroke volume and maximum heart rate (b) Left ventricular mass has increased (to 300g)
(c) Record heart rate with graded exercise and extrapolate to
theoretical max HR OR interpolate theoretical max HR on graph of HR against Question Acceptable
Notes Negates
4 (a) Modifiable: diet, smoking, activity level, obesity, stress
(Non-modifiable: age, gender, heredity, (Any two)
(b) 110 (mm Hg)
[END OF MARKING INSTRUCTIONS]

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