bio 02
J I
A antigen presenting cell B erythrocyte C goblet cells D lymphocytes E lysosomes F mucous membranes G neutrophils H phagosomes I platelets J skin Which letter or letters indicate cells or structures that act as a physical barrier to the entry of a pathogen
E H G A
A antigen presenting cell B erythrocyte C goblet cells D lymphocytes E lysosomes F mucous membranes G neutrophils H phagosomes I platelets J skin Which letter or letters indicate cells or structures that are involved in phagocytosis
836 (± 40) / 8.36 (± 0.4) x 10 , (individuals) y ALLOW per annum / a year , as units or 2 -1 418(±20) /4.18(±0.2)x10 ,peryear/y
Calculate the mean annual decrease in the adélie penguin population between 1988 and 2010.Show your working. Give your answer to three significant figures.
21/2π = 3.344 140.5
Calculate the number of phospholipid molecules in the outer surface of the lipoprotein shown in Fig. 21. Assume that the pattern of proteins and phospholipids shown in Fig. 21 is continued across the whole surface of the lipoprotein. Use the formula: Surface area of sphere = 4πr2
diffusion / net movement , of water across a , partially / selectively , permeable membrane down a , water potential / Ψ , gradient
Define osmosis.
working out the sequence / AW , of nucleotides / bases
Define the term DNA sequencing.
precipitation !!
name the process occurring in stage six of obtaining DNA from leek cells
high(er) , initial / set-up , costs fewer exposed active sites idea that immobilization method might affect shape of active site idea of leakage
one disadvantage of immobilised enzymes
make , single stranded DNA / cDNA / complementary DNA using , reverse transcriptase / reverse transcription make double-stranded DNA using DNA polymerase
one on how to make mRNA into DNA
A
rate of catalase breakdown at 30 seconds A 0.85 B 1 C 1.15 D 1.5 cm3 s-1
binds to antigen on pathogen and,assists binding / binds, to phagocyte
role of opsonins during phagocytosis
idea that one individual or allele has proportionally higher effect on small population (more likely that) alleles will be lost from population (population) more vulnerable / likely to become extinct due , to environmental change / AW
Explain why genetic drift is likely to be of particular concern in the population of 100 cheetahs in Iran.
different (starting) masses (of plant pieces) allows comparison (between plant pieces of different mass)
Explain why it was necessary to calculate percentage change in mass for the vegetables
in most people, the genome is very similar / most genes the same using coding sequences would not provide unique profiles (parts of) non-coding DNA contains variable numbers of , short tandem repeats / repeating sequences
Explain why only selected sections of non-coding DNA are used when profiling a human.
random fertilisation
Explain why the observed results did not exactly match the predicted results. (bird thing)
genetic variation genetic resource / gene bank source of useful alleles can be cross bred with crop varieties allows introduction of different traits unknown future requirements potentially useful in changing climate prevention of inbreeding depression promotion of hybrid vigour prevent dwindling gene pool source of replacement if cultivated
Explain, with reference to selective breeding, why it is important to maintain viable wild populations of crop plant species.
base sequence of normal allele and (known) alternatives held (in database) computational analysis allows rapid comparison of sequences with newly sequenced allele amino acid sequence / protein structures, also held (in database) idea of computer modelling of new protein structure from base sequence
Suggest how the interdisciplinary field of bioinformatics may be useful in determining whether a newly-sequenced allele causes a genetic disease.
promoter
Gene transcription is controlled by transcription factors. Fig. 16.1 shows how a transcription factor can control transcription. Name site A.
(enzymes) re-used so less, money / cost (for new ones) downstream processing / purifying, cost / expense, reduced
Give two economic advantages of immobilising enzymes for large-scale production.
Human population growth: • Need for more agricultural land / housing • Destroys habitats• More waste produced• More pollution produced• Damaging ecosystems• Specific example provided Agriculture: Agricultural land has monoculture / lower biodiversity Loss of older / wild type strains Reduced genetic diversity Subject to disease Inability to adapt to changing conditions Altering habitats Specific example provided such as draining of wetlands reduces habitat diversity Pesticide use Use of fertiliser Nitrate pollution Eutrophication Climate change:• Warmer / drier climate• Modern strains/species not adapted • Migration may not be possible• Rise in sea level reduces land area • More frequent flooding affects terrestrial ecosystems
Global biodiversity is in decline.Human population growth, agriculture and climate change each have an effect upon biodiversity.Explain how each of these factors contributes to the decline in biodiversity.
lipid is less dense than protein ora
Lipoproteins with fewer phospholipids and more protein in the outer layer are known as high density lipoproteins. Lipoproteins with a larger number of phospholipids but less protein are known as low density lipoproteins. Use this information to explain why lipids can increase the buoyancy of aquatic animals.
1 age / stage of development , of , surrogates / mothers 2 (general) health of , surrogates / mothers 3 conditions in which , surrogates / mothers, are kept 4 age / AW , of (implanted) embryo 5 age / AW , of nucleus donor 6 age / AW , of , (enucleated) egg / egg donor 7 number of eggs implanted in each surrogate 8 idea of accounting for advances in technology (over time) available during procedure
List three factors that should have been controlled when compiling the data to include in Table 19.
babies / infantselderly / infirm immuno-compromised / on immunosuppressant drugs / HIV positive known to have been exposed (to the infection)
List two vulnerable groups of people for whom you would advise doctors to prescribe antibiotics although they are not yet showing symptoms of the new disease.
production / AW of , callose release / production , of (named / toxic) chemical leaf drop / abscission necrosis
State two ways in which an individual S tuberosum plant could respond to infection by P infestans
sequence / order, of amino acids
State what structural detail of a polypeptide is altered by gene mutations.
Modifications: 1. Take samples more frequently than every four hours 2. Use a spreader to spread the bacteria on the agar 3. Label petri dish as soon as inoculated 4. Place petri dishes up side down 5. Use a wider range of temperatures/use more intermediate temperature Explanations: 1. Bacteria can reproduce (very) quickly and a big change could occur in four hours so detail of growth may be missed 2. Tilting/ swirling the plate may not spread the bacteria evenly and this would make counting the colonies more difficult and cause the result to be invalid 3. The dishes could easily be confused or mixed up so that the results are invalid 4. Prevents the agar drying out which would reduce bacterial growth and make the results invalid 5. Provides more information about the effect of temperature
A broth culture was incubated at 20C. Every four hours a pipette was used to transfer a sample of the culture to agar growth medium in a petri dish. The sample was spread over the surface of the agar by tilting and swirling the dish. The petri dish was incubated at 30C for 24 hours. After 24 hours the petri dish was labelled and stored in a refrigerator until all results were complete. The procedure was repeated with broth cultures incubated at 10C, 30C and 40C. Once all the agar plates had been collected the student removed them from the refrigerator and estimated population size by counting the visible colonies. Finally the student converted the data into a growth rate. Describe and explain modifications that the student should make to improve the investigation and ensure the data collected are valid. (You may assume that full aseptic technique was used.)
Fertility breed GM stock with non-modified stock see if offspring fertile if so they should be classed as the same speciesora Morphology Compare several individuals from GM and non-GM groups in respect of several physical structures if similar they should be classed as one speciesora Ecology observe how both function in the wild occupy the same or different niche(s) if same niche they should be classed as one species ora Genetics: compare DNA by electrophoresis same pattern should be classed as one species
'Genetically modified plants and animals should be classed as new species'. Outline one experiment or investigation that would provide evidence to support or contradict the statement.
wolf is the result of natural selection selected / evolved to survive in habitat no extreme features dogs bred by artificial selection dogs have extreme features example of extreme features not well adapted to survive in wild
'Man selects for looks; nature selects for survival.'Discuss this statement using examples of dog breeds such as those shown in Fig. 21.
wolf is the result of natural selection selected / evolved to survive in habitat no extreme features dogs bred by artificial selection dogs have extreme features example of extreme features not well adapted to survive in wild
'Man selects for looks; nature selects for survival.'Discuss this statement using examples of dog breeds such as those shown in Fig. 21.
1 use a healthy shoot / cut shoot from healthy plant 2 cut (stem) at a slant 3 between nodes 4 (dip in) rooting powder / plant hormone / auxin 5 place in , soil / compost , and add water 6 (to reduce transpiration) cover with plastic bag / remove some leaves
(i) Describe how to clone a plant by taking a cutting.
bonds contain energy (bonds) can be broken by (respiratory) enzymes soluble so , can move (within cell) H / OH , (groups) can form H bonds with water / allow solubility AVP
(i) Explain how the structure of galactose allows it to be used as a respiratory substrate.
1 & 2 (B)
1 direct contact 2 vectors 3 droplets Which of the methods of pathogen transmission can apply to plants?
F one/ few, types of cell performing a function
A antigen presenting cell B erythrocyte C goblet cells D lymphocytes E lysosomes F mucous membranes G neutrophils H phagosomes I platelets J skin Which letter or letters indicate a tissue explain your answer
F C I J
A antigen presenting cell B erythrocyte C goblet cells D lymphocytes E lysosomes F mucous membranes G neutrophils H phagosomes I platelets J skin Which letter or letters indicate cells or structures involved in preventing the entry of pathogens into the body
recommend GM Bt corn, because spray may not reach all larvae / larvae are inside plant (stem) / shielded from spray
A friend recommends planting genetically-modified Bt corn as it would be more effective against European corn borer larvae rather than spraying unmodified corn with Bt toxin. Which method would you recommend to the farmer? Justify your answer.
work in an inoculating cabinet / maintain minimum plate- opening time flame inoculating loop / use sterile, pipette tip / implement of transfer seal the plates for incubation
A patient has been coughing blood, and it is suspected that bacteria will be found in the blood. A medical technician cultures the blood on an agar plate. What measures should the technician take to keep the agar plate culture sterile?
1 (y-axis) does not show health of individual 2 Dolly was a single individual so perhaps health problems unrelated to cloning 3 only two species shown so trend might not apply to sheep 4 only 3 points in , mouse /AW , study 5 1962 techniques might not be comparable to Dolly the sheep techniques (in 1996) 6 correlation does not imply causation
A student concluded that Dolly's health problems were caused by the stage of development of the sheep that provided the donor nucleus. List three reasons why the information in Fig. 19.2 does not support the student's conclusion.
no data shown for , winter months / Dec / Jan / Feb no data shown about temperature or light idea of fluctuations / dips during summer months another , biotic / abiotic , factor could be causing the increase
A student concluded that the increasing population of algae was due to higher temperatures and higher light intensity in the summer months considering figure 21 is the students data source discuss the weaknesses in this conclusion
no value between pH5.5 and pH6 measured peak / optimum , could be anywhere between pH5.5 and pH6 peak / optimum , for immobilised tannase could be anywhere between pH 5 and pH6.5 no indication that the experiment has been repeated AVP
A student concluded that the optimum pH for this enzyme is pH 5.8 explain why the data in the graph might not support the students conclusion
hydrogen ions used to affect / regulate pH sodium ions used to regulate water potential
A student studied the pack of 'plant food' supplied with some cut flowers. The list of ions included hydrogen and sodium. Suggest what roles these may play in helping the cut flowers to last longer. hydrogen Na+
idea of changes over time figs with units to illustrate population change
The river in which the study was conducted is described as a dynamic ecosystem use figure 21.1 to explain why this ecosystem could be described as dynamic
adapted to occupy the (oil spill) , niche / environment outcompete other , bacteria / species oil is acting as selective agent / selection of bacteria that were able to digest oil
Bacteria that are able to digest and metabolise the hydrocarbons in crude oil are more common in areas, such as around the coast of Alaska and the Gulf of Mexico, where oil spillages are common. Suggest an explanation for this observation.
have significant effect on ecosystem many other species rely on activity of beavers
Beavers are considered to be a keystone species. Explain why they are a keystone species in their native Canada.
molecules are polar(polarity) enables (water) molecules to, attract / bind to, solute molecules
DNA is one of many substances which will dissolve in water. Explain why water is a good solvent.
Carbohydrates: S1. Polymers of glucose E1. Glucose can be used in respiration to release energy S2. Large molecules P2. Insoluble E2. Do not affect water potential of cell S3. 1-4 glycosidic bonds E3. Easy to make and break to release glucose / monomers S4. Coiled shape / compact E4. Take up less space in cell S5. Amylose unbranched / amylopectin with few branches E5. No need for rapid release of monomers in plants S6. Glycogen more branched E6. Allows more rapid release of monomers in animals Lipids (ACCEPT lipids or fats): S7. Fats have more carbon-carbon bonds / carbon-hydrogen bonds P7. Fats are energy rich / contain more energy per molecule E7. More energy stored in less space P8. Fats are insoluble E8. Do not affect water potential of cell S9. Fatty acids are long carbon chains E9. Can be broken down to release two carbon /acetyl groups (which enter Krebs cycle) S10. Animal fats saturated / harderE10. Have role in protection / insulation as well as energy storage.
Describe and explain how the structure and properties of different carbohydrate and lipid molecules suit them to their role as energy storage molecules in plants and animals.
range bars longer range bar indicates more variability / less repeatable
Describe and explain how this problem could be displayed quantitatively on the graph.
primary mRNA is modified removal of introns to produce mature mRNA Alternative splicing can produce different versions of mRNA protein must be activated by cAMP / phosphorylation binding (of cAMP) alters shape of protein
Describe how gene expression can be regulated after transcription.
lay tape measure out from edge of pond place quadrat beside tape measure identify species of buttercup in quadrat count number of plants of each species (in quadrat) repeat for positions of quadrat along tape
Describe how the student would use a belt transect to investigate the distribution of the two buttercup species.
synthesise (a lot of) haemoglobin remove / digest, (named) organelles associated with protein synthesis
Describe the changes that must occur inside these stem cells as they differentiate to form erythrocytes.
the gene / the DNA fragment , inserted into plasmid complementary bases (pair / anneal) formation of hydrogen bonds formation of phosphodiester bonds using (DNA) ligase
Describe the events that are taking place at the step labelled C.
bleeding stops: exposure (of blood / platelets) to collagen in damaged, blood vessel / tissue causes clotting response many factors involved in clotting process soluble fibrinogen converted to insoluble fibres mesh of fibres traps cells and platelets clot prevents bleeding clot dries out to produce scab scab protects against entry of pathogens swelling / redness / tenderness: • infection by pathogen • detection by mast cells • release of, histamine / cell signals, cause response • arterioles dilate allowing more blood to area causing redness • more tissue fluid forms causing swelling (oedema)phagocytes attracted to area phagocytosis of pathogens discomfort in armpits: • excess tissue fluid drained to lymph vessels• pathogens in tissue fluid enter lymph fluid• transported along lymph system to lymph nodes • activity of phagocytes (and lymphocytes) causes, swelling of lymph nodes / discomfort in armpit
Describe the non-specific defences against pathogens that would explain all these observations.
AO2.5 Apply knowledge and understanding of scientific processes in a theoretical context when handling qualitative data inorganic gaseso CO2 and N2 in atmosphere elements fixed to organic compounds o CandNbothformproteins/ nucleic acids incorporated into plants (producers) then animals (consumers) animals obtain element by f eeding on plants decomposing microorganisms break down organic macromolecules in living things release inorganic molecules o carbondioxideandammonium ions microorganisms return element to atmosphere o CO2 released during decomposition o N2 released by denitrifying bacteria
Describe the similarities between the nitrogen cycle and the carbon cycle
chimpanzee has (relatively) smaller / shorter / thinner , thumb longer / narrower , palm thicker fingers wider wrists
Describe two differences between the two images that could have been used to classify humans and chimpanzees in separate families.
nucleus from , tadpole / donor cell , fuses with / enters / AW , (enucleated) egg using , needle / micropipette / electric pulse / electrofusion
Describe what is happening at stage A and suggest a practical procedure that could allow this to occur. (animal cloning)
(antibiotic is) selective pressure (bacterial) gene pool / AW, has variation (only) some bacteria have resistance / some bacteria are more resistant than otherstwo fromwhen exposed (to antibiotic) most-resistant survivesurviving bacteria continue to reproduce to make a resistant population idea that over many generations there is an increase in proportion of resistant bacteria (under continued antibiotic pressure) antibiotic becomes ineffective / new antibiotic needed
Discuss the implications of the over-use of antibiotics when people do not show symptoms.
11-14
Estimate the percentage of land that is covered by woodland
idea that it could encourage the growth of human pathogens
The teacher told the students they should not investigate the growth of bacteria at 35 °C. Suggest why the teacher told them not to grow bacteria at 35 °C.
sequence / order , of bases codes for , sequence / order , of amino acids (each) triplet / three bases / codon , (codes) for , one amino acid
Explain how DNA sequencing allows the sequence of amino acids in a polypeptide to be predicted.
an insertion / deletion will cause frame shift all triplets downstream will be different the protein will have a different sequence of amino acids (downstream of the mutation) the, tertiary structure / three dimensional shape will be different
Explain how a mutation could alter the protein so that it no longer performs its correct function in the cell.
hox gene does not produce transcription factor / transcription factor not activated molecules signalling apoptosis not produced apoptosis (to separate fingers) does not occu
Explain how failure of the control mechanism during development could lead to such a deformity.
(helper T cells) stimulated by antigen-presenting cells release, cytokines / interleukin 2 stimulate B cell proliferation/ clonal expansion
Explain how helper T cells act to speed up these processes.
frameshift altered triplet(s) adjacent / nearby , genes (on same chromosome) switched , on / off idea that new gene could disable a functioning gene if inserted into it
Explain how inserting a new gene into a chromosome could affect the functioning of other genes in that chromosome.
some triplets , code for same amino acid /are degenerate (so) the amino acid sequence is not altered some alternative amino acids will not alter the shape of the protein mutation occurs in intron
Explain how it is possible for a mutation to have no effect on the protein produced from that gene.
(memory cells) not acting in, first line / primary response (memory cells) remained in blood after primary response one of the above linked toso no wait for / faster, clonal selectio
Explain how memory cells caused the differences between the two lines on the graph.
attach to cytoskeleton moved by , protein motors / dynein
Explain how peroxisomes (specific type of vesicles) can be moved around inside the cell.
Indicative points include AO1.1 Demonstrate knowledge and understanding of scientific ideas genetic variation is the variety of alleles offspring have alleles from more than one parent random fertilisation meiosis produces genetically unique gametes AO1.2 Demonstrate knowledge and understanding of scientific processes • crossing over in prophase 1• alleles swapped between non-sister chromatids• base sequence of chromosomes altered• independent assortment / random segregation• in metaphase 1• also relevant in metaphase 2 if crossing over has occurred AO2.5 Apply knowledge and understanding of scientific processes in a theoretical context when handling qualitative data the sperm from one Hydra can fertilise an egg from any other individual Hydra the two Hydra can have different alleles
Explain how sexual reproduction in Hydra leads to genetic variation in the offspring
many, plants / microorganisms, produce molecules that may have medical benefits OR many modern medicines have been developed from traditional remedies many such, plants /molecules, yet to be discovered
Explain how traditional remedies, such as the use of frankincense, provide a strong argument for conservation of biodiversity.
muscle tissue is a group of cells which contract together a muscle is an organ that consists of muscle tissue and other (named) tissues working together (Other named tissues could include: nervous tissue, blood, connective tissue)
Explain the difference between muscle tissue and a muscle.
water enters vacuole pressure against cell wall turgor (pressure) turgid cells (support plant)
Explain the importance of osmosis in plant support.
science knowledge / it, advances / improves / grows
Explain what such developments show about the nature of scientific knowledge.
(many) alleles lost (when population dropped)ora (modern population) descended from few survivors / AW
Explain why a genetic bottleneck can lead to low genetic diversity.
many) alleles lost (when population dropped) ora (modern population) descended from few survivors / AW
Explain why a genetic bottleneck can lead to low genetic diversity.
lactose (contains) beta / β-glucose β-glycosidic bond sugars in opposing orientation / flipped / AW maltose (contains) alpha / α- glucose α-glycosidic bond both (monomers) in same direction / AW
differences between lactose and maltose
Indicative points These could be described in terms of problems associated with selective breeding and solutions offered by maintaining a wild population genetic variation genetic resource / gene bank source of useful alleles can be cross bred with crop varieties allows introduction of different traits unknown future requirements potentially useful in changing climate prevention of inbreeding depression promotion of hybrid vigour prevent dwindling gene pool source of replacement if cultivated population is in danger plausible example(s) of any of the above
Explain, with reference to selective breeding, why it is important to maintain viable wild populations of crop plant species.
C / ribosomes
Fig. 20.1, on the Insert, shows a transmission electron micrograph of part of a eukaryotic cell. (a) (i) (ii) Identify one feature inside the cell that would also be seen in a prokaryotic cell.
make , single stranded DNA / cDNA / complementary DNA using , reverse transcriptase / reverse transcription make double-stranded DNA using DNA polymerase
First, instead of isolating DNA that contains the insulin gene, mRNA that codes for insulin is extracted from human pancreas cells. What needs to be done with the mRNA in order for the rest of the genetic modification to be completed?
some crop plants cannot reproduce , sexually / from seed young seedlings , less likely to survive / AW quicker than , growing from seed / sexual reproduction uniform / predictable , shape / size / quality / yield idea of easier to harvest (propagation) can be done , at any season / time of year
Identify three advantages of vegetative propagation in agriculture.
Any two from: A rough endoplasmic reticulum D Golgi apparatus E secretory vesicle F mitochondrion
Identify two features of this cell that confirm it is not a prokaryotic cell. In each case state the letter and the name of the feature
species diversity will rise as more species live in the new habitats genetic diversity will increase as species have a wider range of conditions in which to live
Increasing habitat diversity may lead to an increase in species diversity and genetic diversity. Explain why species diversity and genetic diversity may be increased as a result of the beavers' activity.
mutation / genetic diversity natural / directional , selection idea that environment / selection pressure , is different from the 'other' population time
Islands, such as Madagascar, often have species that are different from those on the nearest land mass because they are reproductively isolated.State three other conditions that must be present in order for speciation to occur.
control idea of checking for contamination
No bacteria were detected at any time in the flask that was inoculated with nutrient broth that did not contain bacteria. Explain the purpose of this flask.
1 zero the colorimeter / set to zero 2 using blank 3 use red filter 4 use known concentrations (of lactose) 5 (produce) serial / series , dilutions 6 construct calibration curve 7 test unknown sample (using the same method) 8 use / read from , graph / calibration curve , to determine (unknown) concentration
Lactose is a reducing sugar. Benedict's reagent can be used to detect the presence of lactose in a solution. A colorimeter can be used to measure the concentration of lactose. The colorimeter first needs to be calibrated. Describe how a method that uses Benedict's reagent and a colorimeter could be calibrated to measure the concentration of lactose in an unknown sample.
1 asexual / vegetative , reproduction 2 (development of) body plan 3 proliferation of white blood cells 4 producing gametes from haploid cells 5 production of new stem cells
Mitosis is involved in growth and repair of tissues. State two other roles of mitosis in multicellular organisms.
thermostable OR does not, denature/AW, at95 C(during DNA strand separation) so PCR can be cycled repeatedly without stopping (to reload with enzyme)
Modern PCR technique uses DNA polymerase from the bacterium Thermus aquaticus. Why is this enzyme chosen?
1 appropriate calculation of , observed / expected , population density 2 lower than estimate 3 so does not support 4 low / unknown , repeatability / reproducibility (of results) 5 (some) support because , figure / 3 , is close (enough) to , estimate / 5 6 some individuals not photographed 7 idea that if many individuals not trapped population could be higher than estimate
Most studies estimate the population density of jaguars in the South American rainforest to be 5 individuals per 100 km2. In the 2007 study: 2 100 camera traps were set up covering an area of 271 km . 28 images of 9 different jaguars were recorded. How well do these results support a population estimate of 5 individuals per 100 km2?
oats , large seeds
Name one example of a plant that has been bred by farmers to show exaggerated features and describe the feature that has been exaggerated.
Glucose monomer monosaccharide no glycosidic bonds C6H12O6 /moreHandO Starch polymer polysaccharide glycosidic bonds C6H10O5 /lessHandO
Name three main structural differences between starch and glucose
created dams flooded areas upstream / reduced flow rate downstream , creating still / slow moving water for aquatic species felled trees opened up tree canopy allowing light to ground level built lodges creates sheltered habitat for insect species / beaver parasites
One benefit of the reintroduction of beavers in Scotland was an increase in habitat diversity. Explain how the following activities could have contributed to increased habitat diversity. constructed dams felled trees built lodges
human sightings: idea of any one of the following misidentification seeing the same individual twice exaggeration / lying poor recollection jaguars likely to be in , places / times , humans are not method unlikely to spot cubs (as still in den) footprints: idea of any one of the following misidentification might disappear (before recording) multiple prints in same spot makes counting difficult same print might be counted on different occasions many prints made by the same individual hard to distinguish individual jaguars footprints not always left
Other evidence used to estimate the jaguar population includes footprints and reports of sightings by local humans. Suggest one disadvantage of each of these methods for estimating the size of the jaguar population.
sequencing 1. (high) mutation (rate) means many , strains / AW , of virus exist 2. can predict (viral) , strain / protein / antigen 3. (so) vaccine contains correct antigen bioinformatics 1. facilitates access to large amount of data 2. facilitates access to data on DNA and proteins 3. idea that format (of information) is universal 4. can identify source of outbreak 5. can identify vulnerable populations 6. vaccination program can target certain , area / individuals
Outline how DNA sequencing and bioinformatics could be used to increase the effectiveness of a vaccination programme against ebola.
B cells / lymphocytes, have, antigen receptor / carry antibody, on surface, specific / complimentary to, only one antigen selected / activated, B cell, proliferates / clones / divides by mitosis forms / differentiates into, plasma / effector, cells which secrete antibodies specific / complementary, to antigen
Outline the processes that lead to the production of antibodies against an unfamiliar bacterium.
artificial passive as injected (patient) is not producing , antibodies / memory cells / immune response
People have recently recovered from chickenpox can donate plasma so that their antibodies can be given to leukaemia patients with weakened immune systems. What type of immunity is this and explain why.
E, B, D, C, A
Place the following steps in the correct sequence. The first and last ones have been done for you. A place sections in order by matching overlapping regions B cut DNA into sections of varying length C sequence short sections of DNA D amplify the DNA (create many copies) E extract samples of DNA from cells
(paper) chromatographySet, blots / AW, of the two (urine) samples separate with aqueous solvent use a stain/ ninhydrin to visualise spots compare patterns
Plan a method to compare the amino acids present in the urine of a person who has been following one of these diets with that of a person who has not.
water enters vacuole pressure against cell wall turgor (pressure) turgid cells (support plant)
Plants rely on osmosis for support.Explain the importance of osmosis in plant support.
sulfur
Polypeptides contain carbon, hydrogen, oxygen and nitrogen name one other element present in polypeptide
loss of farmland due to flooding strength of argument depends on area affected (probably) not a strong argument as relatively small areas affected trees cut down(of concern to foresters) likely to occur only in area near water - so not a strong argument damage to river bank needing costly repairs cost should be shared by all who benefit (including those downstream) so not a strong argument
Some land owners have expressed concern about the impact that beavers can have on rural businesses. Suggest two arguments that may be used by local business leaders against the introduction of beavers. State whether these outweigh the arguments presented by the naturalists. argument 1 argument 2
supports because... Adélie / ice-reliant / AW , penguin (population) decreased OR gentoo / chinstrap / non-ice-reliant , penguin (population) increased figs that support either point given above does not support because...idea that changes could be explained by (chance) arrival of , gentoo / chinstrap (and subsequent competition) change in another described factor could explain changes (in a single species) correlation does not mean causation
Scientists have claimed that the population changes in the three penguin species on the island suggests that the Antarctic temperature is increasing. (i) Discuss whether the information in Fig. 17 supports the scientists' claim. You should refer to the data in Fig. 17 in your answer.
light (microscope) because: subcellular structures / (named) organelles , not visible wide field of view magnification , (only) 1000 / < 2000 / within LM range colour visible
State the type of microscope that was used to view these images (of cell division). Justify your answer.
microorganisms grow more quickly and can produce more protein per, hour / day / week microorganisms can be grown on waste material from other processes beef has five times the total fat content of protein produced by microorganisms ORA beef has 20 times the saturated fat content and is more likely to contribute to atherosclerosis / heart disease ORA fungal protein has no cholesterol and is less likely to contribute to, atherosclerosis / heart disease people on a weight reduction diet prefer fungal protein as it has half the energy content of beef AVP
Some people think that we should produce fungal protein rather than beef for human consumption. Use Table 18.1 and your own knowledge to discuss this claim
Any four from: microorganisms grow more quickly and can produce more protein per, hour / day / week microorganisms can be grown on waste material from other processes beef has five times the total fat content of protein produced by microorganisms ORA beef has 20 times the saturated fat content and is more likely to contribute to atherosclerosis / heart disease ORA fungal protein has no cholesterol and is less likely to contribute to, atherosclerosis / heart disease people on a weight reduction diet prefer fungal protein as it has half the energy content of beef AVP
Some people think that we should produce fungal protein rather than beef issued consumption used table 18 and your own knowledge to discuss this claim
valid (V) because the indicative point may be subsumed within reference to a supporting figure recent divergenceo figs to support from Fig 19.3 occupy same branch on phylogenetic tree o as seen in Fig 19.1 invalid (I) because the indicative point may be subsumed within reference to a supporting figure divergence less recent than chimpanzee and bonobo o figs to support from Fig 19.3 o as seen in Fig 19.1 different anatomy o as seen in Fig 19.2 prinicples of classification (P) may be implied during discussion of V and I points phylogeny is basis of classification species that , diverged recently / share similar base sequence , occupy same group original classification based on comparative anatomy recognition that biochemistry is more accurate than comparative anatomy scientific knowledge develops over time change justified by new molecular evidence
Some scientists have suggested that humans and chimpanzees should be reclassified as belonging to the same genus.Evaluate their suggestion using evidence from Figs. 19.1 to 19.3 and your own knowledge of the scientific basis for the classification of organisms.
Indicative scientific points may include: Results not valid Objections: • cause of collapse not recorded / plants may have collapsed for different reasons • number of collapsed less meaningful than percent Improvements: • determine which plants collapsed due to corn borer • dissect stems to seek larvae • use percent collapsed out of, original / still standing, numbers. Results may not be accurate Objections: • collapsed plants may have been counted twice from plot-edge • some collapsed plants may not have been noticed from plot-edge • students may have counted differently from each other Improvements: • remove / mark, collapsed when counted • use narrow strips as plots so that collapsed not missed • have all plots counted by the same student • have more than one student counting • average the counts. Variables not controlled Objections: • no account of natural variation in plant susceptibility • genetic variations between Bt and regular corn Improvements: • use, cloned / genetically identical, plants in each plot. • perform genetic modification to Bt on same clones as used for other plots.
Some students investigated the different ways of protecting maize plants against the corn borer moth. In each of three separate but close-together square plots, in the same field, they planted several hundred maize seedlings. Plot A: untreated (control). Plot B: sprayed daily with Bt toxin. Plot C: the seedlings planted were genetically modified Bt corn. On the first day of each week, one student would walk around the edge of a plot and count the number of maize plants that had collapsed in that plot. Each plot had a student responsible for counting. The results are shown in Table 20.1.The students' tutor raised a number of concerns about the investigation. In summary: The methods were not a valid test of what was being investigated. The results may not be accurate. Some variables were not controlled. Explain why these concerns are justified and suggest improvements to the investigation.
procedure tissue culture / micropropagation asepsis important because reduces , microorganisms / contamination
State how a clone of potatoes could be produced for this investigation and explain why it is important to carry out this procedure under aseptic conditions.
high throughput sequencing
State one development, other than nanopore technology, that has led to an increase in the speed at which DNA can be sequenced.
in , (named) matrix / gel adsorption / bonding to (named) carrier membrane separation cross-linking / covalent bonding ALLOW entrapment / encapsulation / inclusion / microcapsulation ALLOW carrier boundALLOW attached to partially permeable membrane
State one method by which an enzyme could be immobilised
(increase in antibiotic) resistance
State one valid concern that people have about the genetic modification of bacteria.
genetic polymorphism / proportion of heterozygotes / proportion of gene variants
State one way in which genetic diversity can be measured.
cytokines attract / AW , (named) phagocytes opsonins bind to / AW , pathogens / foreign cells / antigens , and increase phagocytosis / recognition by phagocytes
State the role of cytokines and opsonins in phagocytes
two , 6-membered rings / hexoses (1-4) glycosidic bond two CH2OH (groups) rings contain one , oxygen atom / O
State two other structural similarities between lactose and maltose.
use of marker (gene) (genes for) fluorescence / colour change (examine fluorescence under) UV , light / radiation antibiotic resistance (gene) (then) grow on agar containing antibiotic
Step D results in a transformed bacterium. Many individual bacteria are not transformed successfully during this procedure. Explain how scientists can determine the success of step D in this procedure.
1 bacteria gain , nutrient / mineral / food , from , it / detergent 2 structures / AW (in fig. 21.1) contain only C and H 3 bacteria need (named) elements other than C and H example of other element linked to use in bacterium 4 absence of other elements is a limiting factor (for bacterial growth)
Student A concluded that the detergent speeded up the rate of hydrocarbon breakdown only because it increased the surface area of hydrocarbon upon which the bacteria could grow. Student B concluded that the detergents also increased the growth of the bacterial population by an alternative mechanism. Use the information in Fig. 22 and your knowledge of bacterial growth requirements to provide support for student B's conclusion.
idea of data from investigation that controls surface area or elements available (information about) elements / AW , present in the detergent
Student B concluded that the detergents also increased the growth of the bacterial population by an alternative mechanism. Suggest one piece of evidence that would further support student B's conclusion.
1 bacteria gain , nutrient / mineral / food , from , it / detergent 2 structures / AW (in fig. 21.1) contain only C and H 3 bacteria need (named) elements other than C and H example of other element linked to use in bacterium 4 absence of other elements is a limiting factor (for bacterial growth) idea of data from investigation that controls surface area or elements available (information about) elements / AW , present in the detergent
Student B concluded that the detergents also increased the growth of the bacterial population by an alternative mechanism. Use the information in Fig. 22 and your knowledge of bacterial growth requirements to provide support for student B's conclusion. and Suggest one piece of evidence that would further support student B's conclusion.
detergent works as an emulsifier / attracts phospholipid molecules and water molecules it will break up the plasma / nuclear membranes
Suggest a suitable substance the student could use to release the DNA, and explain why it should work.
1 (autosomal) linkage 2 (both) genes / alleles , occur on same , chromosome / autosome / chromatid 3 no independent assortment 4 (so) alleles , inherited together / end up in same gamete 5 (unless) crossing over occurs / chiasma forms between gene loci
Suggest and explain one reason, other than epistasis, why the phenotype ratio might not be 9:3:3:1.
penguin species have overlapping / AW , niches competitive exclusion increase as , food / nesting sites / resources (available) increase as , no / little , competition / limiting factors plateau / drop, because of (increased) competition drop / plateau , due to , arrival of / competition from , gentoo
Suggest explanations for the changes in the population of chinstrap penguins between 1976 and 2010.
Europeans: (pre-agricultural) gene pool/genetic variation, included mutant / non-intolerance, allele availability of milk acted as (positive) selection pressure individuals / groups, with mutant / non-intolerance, allele had better, chance of survival / success in reproduction directional selection mutant / non-intolerance, allele accumulated (in gene pool) genetic drift (in small prehistoric population) mutant / non-intolerance, allele is dominant so expressed in heterozygotic individuals (increasing phenotype frequency). Australian aborigines: ancestral population pre-agricultural so no selection for mutant / non-intolerance, allele no suitable mammals to domesticate / milk island, so no borders for suitable mammals to come in no contact / breeding, with non-Aboriginal peoples no gene flow (from other human populations) no selection pressure to increase mutant / non-intolerance, allele / phenotype, frequency.
Suggest how the lactose intolerance phenotype came to be present in only 5% of a population like the Europeans, but came to be present in 97% of the Australian aborigines. Use the information given above and knowledge of Darwin's theory of evolution by natural selection.
cut block in half measure, thickness of colourless region / distance from edge of block to coloured region divide distance (acid diffused) by time
Suggest how the student could use the partly-discoloured blocks to measure the rate of diffusion.
competition
Suggest one biotic factor that might affect the distribution of the buttercups.
ecotourism / education / scientific studywater quality improved as silt is held back by dams
Suggest one other benefit of the reintroduction of beavers.
(nucleic acid) base sequence / amino acid sequence genes / DNA / RNA / cytochrome C
Suggest one other piece of evidence that could be used to provide/support of the classification of algae
(can be grown into different tissues to) test how effective new medicinal drugs are (can be grown into different tissues to) test for side effects / toxicity of new drugs (can be grown and) studied to see how they develop into different cell types (developmental research) cell function can be studied to find out what can make it fail to work properly in certain (named) diseases
Suggest three ways in which the use of embryonic stem cells in research has practical benefits to biological knowledge.
low cost rapid reproduction (rate) / more generations in a given time idea that fruit fly genetics / development is well understood simple , genetics / body plan (many) mutations / structures , observable with , light / low powered , microscope
Suggest to other reasons (other than ethically accepted) that fruit flies are chosen to research into genes controlling the development of body plans
reduction in extent of icechange in ocean current change in (penguin) food (species or population) new , disease / parasitechange in predator (species or population) new animal (species) present on land change in population of (aquatic) plants
Suggest two further pieces of evidence that the scientists might have found to support their claim.
light intensity light duration soil (named) mineral (content) soil , water / moisture (content) soil type soil pH humidity air pollution
Suggest two other abiotic variables that this precaution was intended to control.
low cost / rapid reproduction (rate) or genetics / development , well understood (more) similar / AW , to humans idea that can show effects are generalisable to more than one species idea that more than one species is needed to demonstrate conservation of base sequence
Suggest two reasons why mice are also used to investigate the genes controlling the development of body plans
Products not contaminated with enzyme Extraction of enzyme not needed recycling of enzyme idea that process can be run over wider temperature range (bioreactors) can be run continuously for long periods, so less emptying / cleaning needed
Suggest two reasons why using immobilised enzymes in industrial processes could be cheaper than using free enzymes
prevents pathogens entering wound aromatic compound is antibacterial
Suggest two ways in which frankincense contributes to defending the tree from pathogens.
breaks down / digests / removes , proteins associated with DNA / histones
Suggest why a protease enzyme added in step 3 is needed to purify DNA
genetically identical offspringoffspring produced , rapidly / in large numbers (all) offspring will , find conditions favourable / have same adaptations
Suggest why hydra reproduces asexually when conditions are favourable
reduced / no , genetic variation control (more) variables increases validity
Suggest why it is important to use clones in an investigation such as this.
estimate will be inaccurate (because of low numbers) dangerous (for collector or jaguar)
Suggest why it was not appropriate to estimate the number of jaguars using the capture-recapture technique.
(some offspring) might survive unfavourable conditions (some) offspring have useful alleles (named) unfavourable conditions mean (all) offspring might die (if asexual)
Suggest why sexual reproduction in hydra usually occurs in the winter
more combustion / less photosynthesis
Suggest why the concentration of carbon dioxide in the atmosphere increases during the winter and decreases during the summer
(immobilised enzymes are) less easily denatured shape / tertiary structure , supported / AW (by support material) idea that part of enzyme not fully exposed to pH (8)
Suggest why the immobilised enzyme is more active at higher pHs than the free enzyme
(mouse and Xenopus) have , different / not comparable ,lifespans (mouse and Xenopus) develop / mature , at different rates frog , has tadpole stage / lays eggs ora
Suggest why the x-axis does not show the age of the donor nuclei.
reduce impact of , anomalous / AW , results measure / increase / show / ensure , repeatability allow , calculation of standard deviation / (named) statistical test (calculated) mean likely to be , more accurate / closer to true value (than individual value)
The teacher also suggested that the students should have carried out the investigation using three flasks at each temperature. Explain how this suggestion would have improved the students' investigation.
(mammal diet high in milk, so) high lactose concentration (structural) gene for protein channel / lactose permease gene / lac Y , is , transcribed / expressed / switched on (protein is) lactose permease
The E coli living in the digestive system of young mammals are more likely to contain this protein than E coli living in the digestive system of old mammals. Suggest an explanation for this observation.
artificial breeding / selection can exaggerate features other characteristics may be ignored(may be) detrimental to health (of dog) club provides guidance / advice to maintain welfare
The Kennel Club is an organisation that protects and promotes the health and welfare of dogs. It also publishes descriptions to define each breed.Explain why such an organisation is necessary.
no / little , because , homeobox genes / they , are highly conserved (within animal kingdom) (only) that humans and chimpanzees , belong to the same kingdom / are animals
The base sequences of homeobox genes in humans and chimpanzees are almost identical. What conclusions about the evolutionary relationship between humans and chimpanzees can be drawn from this piece of evidence?
1- light 2- PH
The clones were planted in adjacent fields in order to control variables such as temperature, wind speed and rainfall. Suggest two other abiotic variables that this precaution was intended to control.
1. homeobox 2. DNA 3. transcription 4. plant 5. kingdoms
The development of body plan in eukaryotic organisms is controlled by ___1__ genes. these genes code for proteins that are able to bind to ___2__ and turn specific genes on and off and are known as ___3___ factors. These proteins contain a sequence of base pairs that varies little between species within the animal __4__ or fungus __5_____.
D increase number of plants in each group E facilitates identification of anomalies E increases accuracy of the meanE allows assessment of repeatability / precision D calculate mean E more representative of treatment D calculate range / standard deviation E add bars to graphE measures variability of results E standard deviation less affected by anomalous results D perform statistical test / (unpaired) Students t- test E assess significance of difference E because comparing 2 means
The farmer grew one of the cuttings in soil fertilised with solution A and the other cutting in soil fertilised with solution B. The farmer took several other precautions to increase the validity of the investigation, including: growing the plants in the same type of soil exposing the plants to the same light intensity. After a set period of time the farmer measured the increase in height of the lavender plants. The farmer's results are shown in the table below. The farmer concluded that solution A increased the height of lavender more. A student said that, even though the investigation was valid, the results did not give strong support to the farmer's conclusion. Describe and explain how the investigation could be improved in order to have more confidence in any conclusions drawn from the results.
supports because... species B has greater (calculated genetic) polymorphism (than species A) ora might not support because... numbers / polymorphisms , are similar no statistical test performed might not have sampled same loci no indication of (fruit flies) sample size
The first group of scientists study the 26 gene loci from species A. they calculated the genetic polymorphism species a to be 0.35 the second group of scientists study 30 gene loci of species B they found the genetic polymorphism of species be to be 0.41. evaluate the conclusion that species B shows greater genetic polymorphism than species A.
many mitochondriato supply , energy / ATP , for movement OR enzymes / acrosome (enzymes) to , penetrate / AW , egg
The flagella allow the sperm to move towards an egg suggested and explain an adaptation that is likely to be present in these cells
Fossa has ... longer , legsdifferent (shaped / size) , ears (proportionally) bigger eyes
The mongoose is a smaller mammal and also has proportionally longer fur. State one other difference, visible in Fig. 20.2, between a fossa and a mongoose.
(population) not (sufficiently) large (population) not randomly mating / not subject to selection
The population of students varies year from year so cannot be said to be stable State two other reasons why it might be inappropriate to use the hardy Weinberg principle to estimate allele frequencies for the results in the table.
reduced / no , genetic variation control (more) variables increases validity
The resistance of different varieties of S tuberosum to infection by P infestans was investigated.(i) Suggest why it is important to use clones in an investigation such as this.
range bars longer range bar indicates more variability / less repeatable
The student found it very hard to determine exactly when the colour completely disappeared. The results were not easily repeatable. Describe and explain how this problem could be displayed quantitatively on the graph.
light temp no. of seeds per pot size of pot
The student planted R. bulbosus seeds into five pots and maintained the soil moisture in each pot at a different level (0%, 20%, 40%, 60% and 80%). This was repeated with seeds of R. repens. After four weeks the student counted the number of plants that had germinated in each pot. (i) State two factors that should be controlled as part of this investigation.
(use a) 100cm3 measuring cylinder mix 80cm3 acid and 20cm3 water take 50cm3 of the resulting solution and add 50cm3 water repeat 50 / 50 dilution for each subsequent solution required / AW
The student was supplied with a solution of 1M hydrochloric acid. The student decided to make 50 cm3 of each solution required. (0.8, 0.4, 0.2, 0.1) Describe how the student created the concentrations shown using a serial dilution technique.
longer time taken to discolour error becomes smaller proportion of total / % error reduced
The student was using 10 mm agar blocks. The teacher suggested that using larger agar blocks could make the results more easily repeatable.Explain why using larger agar blocks would make the results more repeatable.
1 should have used E 2 (has) most / more , (countable) colonies 3 idea that anomalies will have smaller effect 4 more representative / larger , sample 5 (fewer serial dilutions) decreases chance of error 6 F (is appropriate) because , colonies / AW , are countable
The students disagreed about which tube's result to use as a starting point for their calculation. Discuss whether the petri dish resulting from Tube F was the most appropriate for them to use.
reduce impact of , anomalous / AW , results measure / increase / show / ensure , repeatability allow , calculation of standard deviation / (named) statistical test (calculated) mean likely to be , more accurate / closer to true value (than individual value)
The teacher also suggested that the students should have carried out the investigation using three flasks at each temperature. Explain how this suggestion would have improved the students' investigation.
If cell B is measured and formula applied... 1.7 (± 0.4) If working back from information given about cell A... 2.2 (± 0.4) (number less than 10) x104 (μm3)
The volume of cell A is 5.4 × 104 μm3. Assume that cell B is spherical.Calculate the volume of cell B.Use the formula: volume of sphere = 43πr3 Give your answer in standard form in μm3.
Genetic code (G) DNA base sequence codes for amino acid sequence reference to mRNA base sequence triplet code / 3 bases = 1 amino acid degenerate code substitution could result in same amino acid Transcription (C) transcription then translation complementary base pairing synthesis of mRNA strand role of RNA polymerase Translation (L) mRNA binds to ribosome tRNA binds to mRNA tRNA brings specific amino acid mRNA translated into polypeptide Effect of y allele (M) substitution / frame-shift different base sequence of DNA different mRNA codon different tRNA anticodon tRNA brings different amino acid different sequence of amino acids amino acid sequence is primary structure
The yellow colour in peas is the result of an enzyme that breaks down chlorophyll, which is green. The Y allele codes for the production of an enzyme that breaks down chlorophyll. The y allele is the result of a mutation in the Y allele. The y allele codes for an inactive form of this enzyme. (i)* Outline how the Y allele codes for the production of this enzyme and explain why the y allele codes for an enzyme with a different primary structure.
two from cutting needs less / micropropagation needs more, (expensive) equipmentcutting needs less / micropropagation needs more, (expensive) skills / staff / AW cutting produces less / micropropagation produces more, clone offspringAVP
When a genetically modified plant is created, it may be cloned into many plantlets in the process called micropropagation. Compare the equipment and techniques of taking cuttings with those used for micropropagation.
1 volume of broth (in flask) 2 pH (of broth) 3 oxygen (concentration in flask) 4 number / concentration , of bacteria in , broth at beginning / AW 5 volume removed (from each flask) 6 (standard) stirring / mixing , before withdrawal of samples
Three flasks containing identical solutions of nutrient broth were used. Flask 1: inoculated with 1cm3 of broth containing the bacterium Bacillus subtilis and incubated at 20°C. Flask 2: inoculated with 1cm3 of broth containing B. subtilis and incubated at 30°C. Flask 3: inoculated with 1cm3 of broth containing no bacteria and incubated at 30°C. Aseptic techniques were used throughout. At set times over the next 3 days the students removed samples from each flask and measured the number of viable bacteria present. (a) State one further variable the students should have controlled in their investigation in order to produce valid results.
dilute the sample taken from the colony multiply result from agar plate by dilution factor
Too many colonies unable to count Describe a modification to the procedure that would enable the student to estimate the population size
courgette / carrot or courgette 0(%) mass change / idea of intercept , between 0.3 and 0.5 (mol dm-3) (courgette associated with) highest concentration at which there is no mass change (courgette has) highest mass gain at 0 mol dm-3 /least mass loss at 0.7 mol dm-3 change / AW , at , 0.3 (mol dm-3) higher than carrot / 0.5 (mol dm-3) lower than carrot AVP
Use Table 16 to identify which plant cells contained the highest concentration of sucrose. Justify your conclusion.
1a species (bio)diversity / variety of species / species evenness 2a shown by calculated Simpson's Index or 1b species (bio)diversity / number of species / species richness 2b shown by 5 (plant species) 3 variety / diversity / range , of habitats 4 shown by , coppiced and mature / reference to two woodland , habitats / AW 5 idea that genetic diversity not measured by or evident from students' fieldwork
Use the example of the students' fieldwork to explain how biodiversity can be considered at different levels.
ok big N is whole number (not mean !!) and make sure to do 1- at end
Use the information in the table 18 to work out the Simpsons index of diversity for the area of coppice Wood land
three columns with clear headings quadrat number / distance from pond in left hand column number of plants / % cover in right hand column(s)
Use the space below to show the format of a results table suitable for recording the results of the student's investigation. (You do not need to include any suggested data.)
three columns with clear headings quadrat number / distance from pond in left hand column number of plants / % cover in right hand column(s)
Use the space below to show the format of a results table suitable for recording the results of the student's investigation.(buttercup)
(shows) total / cumulative , infection over time(of study) idea that on different days the level of infection could be different any reference Fig.18 to support
Using Fig. 18, suggest why the area under the curve is used as a measure of infection rather than the area of leaf that is visibly affected on a given day.
little / nothing (can be concluded) because no (named) statistical test done If no other marks awarded, ALLOW 1 mark only for...(probably) not significant because , error bars / standard deviations , overlap
Using only Fig. 20.1 and your answer to (i), what can be concluded about the significance of the difference between the length of male and female cheetahs aged between 2.5 and 4 years?
protoctista NUCLEUS / (named) membrane-bound organelles , so eukaryotic/ not prokaryotic unicellular so not plant(ae) cell wall / chloroplast / starch grains, so not animal(ia) cellulose cell wall / chloroplast , so not fungi
Using the information given above draw a conclusion about which kingdom is the most appropriate in which to classify algae. also explain what other kingdoms are not appropriate choices
hormone enters cell and binds to a transcription factor transcription factor activated binds to, site A / promoter region RNA polymerase able to bind
Using the information in Fig. 16.1, describe how transcription can be controlled in eukaryotes.
Species B [no mark] produces more biomass continues to produce biomass at low glucose concentration
Using the information in Fig. 18.1 suggest which species would be better for use in production of fungal protein for human consumption.Explain your choice.
Sanger / chain termination technique Only 5 errors per 100 000 nucleotides compared to, 50 in Roche pyrosequencing / 500 in SOLiD / 1000 in Helicos
Using the information in Table 17.1 decide which technique is best to use when sequencing a human gene that causes a genetic disease. Explain your choice.
Comparison of curves Level 2 (3-4 marks) similar lag phase quicker overall at 30°C exponential phase rises faster at 30°C shorter duration of stationary phase at 30°C faster death phase at 30°C lower population at 30°C after 72h figures used to support Explanation for difference at higher temperature molecules have more kinetic energy bacterial enzymes closer to optimum temperature faster enzyme activity more competition for nutrients earlier resources, e.g. carbon source, used up more more quickly toxic metabolites produced more quickly
Using the information in Table 19.2, compare and explain the patterns of growth seen at 20°C and at 30°C.
uses / AW , water (to) break 3 ester bonds lysis means splitting and fatty acids are , split / AW , from glycerol
Using the structure of triglyceride molecules as an example, explain what is meant by hydrolysis.
Nitrosomonas nitrite Nitrobacter nitrate
complete flow chart: nitrogenous compound ---(step 1)-->___________----(step2)--->______-------> uptake by plants
ice , is less dense than water / floats ice , provides habitat for some species / AW (floating) ice insulates (water below) (aquatic) animals / gametes / spores , can move or oxygen / nutrients / resources / AW , can circulatewater is similar density to living organisms organisms can float
Water has many properties that are essential for living organisms. Explain how properties relating to the density of water contribute to the survival of organisms.
the correlation (between moisture and germination) is not significant (at the p = 0.05 / 95% confidence level)
What can the student conclude about the correlation between soil moisture and germination in R. repens?
there is no significant difference between the expected and observed results
What can you conclude about the observed results collected by the breeder in Table 17.1? (bird thing)
non-competitive (inhibition) the rate of reaction does not continue to rise as substrate concentration rises / in competitive inhibition the rate of reaction would continue to rise as substrate concentration rises
What can you conclude from Fig. 20.2 about the type of inhibition shown? Explain your answer.
no / little , because , homeobox genes / they , are highly conserved (within animal kingdom) (only) that humans and chimpanzees , belong to the same kingdom / are animals
What conclusions about the evolutionary relationship between humans and chimpanzees can be drawn from this piece of evidence?
(shape of), proteins / glycoproteins / glycocalyx / antigens of the plasma / cell surface, membrane
What feature of a pathogen such as Mycobacterium tuberculosis could be altered by a mutation, making a vaccine ineffective?
light microscope graticule
What laboratory equipment would you select to make an accurate measurement of the length of Paramecium caudatum?
urea / uric acid
What nitrogenous excretory molecule from the decomposers would pass to the next stage of the nitrogen cycle?
electrophoresis
What technique would you plan to use, to compare digested and amplified fragments from the two DNA samples?
1 allopatric speciation 2 different , selection pressure / environmental conditions (from mainland) 3 (random) mutation 4 (fossa-like) individuals with , mutation / (new) feature , survive / reproduce ora 5 beneficial / AW , alleles passed on 6 directional selection
When the island of Madagascar became separated from the African continent, there were no members of the cat family, Felidae, on the island.Outline how a fossa could have evolved from a much smaller, mongoose-like ancestor
2 & 3
Which of the following processes occur during DNA replication? 1 breakage and (re)formation of phosphodiester bonds 2 breakage and (re)formation of hydrogen bonds 3 alignment of free nucleotides with their complementary bases
(pond community is) final / stable / not subject to further succession
Why might ecologists call this a 'climax community'?
supports because... 1 (critical / table , value =) 7.82 2 difference is significant as (Χ2) , higher than , 7.82 / critical value 3 (less than) 5% / 1 in 20 , probability / chance , that difference is due to chance ora 4 Χ2 / calculated value is , smaller than , 9.35 / value at p=0.025 5 greater than , 2.5% / 1 in 40 , probability that difference is due to chanceora
Yy pea plant chi squared value is 8.8 at 3 degree of freedom 0.05 is 7.82 what does this tell us
in , (named) matrix / gel adsorption / bonding to (named) carrier membrane separation cross-linking / covalent bonding
enzyme immobilisation
lay tape measure out from edge of pond place quadrat beside tape measure identify species of buttercup in quadrat count number of plants of each species (in quadrat) repeat for positions of quadrat along tape
i)Describe how the student would use a belt transect to investigate the distribution of the two buttercup species.
flaming the tube causes air to expand and pushes bacteria away so less likely to settle into tube kills bacteria on neck of tube holding lid of petri dish over agar plate avoids infection / inoculation with bacteria in the air
why a) flame tube b)lift lid at an angle
low cost rapid reproduction (rate) / more generations in a given time idea that fruit fly genetics / development is well understood simple , genetics / body plan (many) mutations / structures , observable with , light /low powered , microscope
why fly used
low cost / rapid reproduction (rate) or genetics / development , well understood (more) similar / AW , to humans idea that can show effects are generalisable to more than one species idea that more than one species is needed to demonstrate conservation of base sequence
why mouse used
