Revision questions · ⁨Questões de revisão⁩

Convert both lengths using their own scale bars

• A scale bar provides a known real distance in the same image. Convert the image length and real length to the same unit before dividing. Magnification is a ratio and has no unit.

300

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

To remove surface solution consistently

• Use percentage change to compare samples with different initial masses. A zero percentage change estimates a solution concentration with no net water movement. This is an estimate from a trend, not proof that water molecules stop moving.

-10 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

A main DNA loop without a nucleus

• Use structures rather than size alone to identify a cell type. A plant cell has a cellulose cell wall, but a bacterial wall is not made of cellulose. Not every bacterium has a plasmid. A small cell image can be enlarged, so image size cannot by itself show real cell size.

10

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Ribosome · ⁨Ribossomo⁩

• Link structure to function: chloroplasts contain chlorophyll to absorb light; the vacuole helps support a turgid cell; the membrane is a selective boundary rather than a rigid support. Most animal cells have the five named structures, but specialized cells can differ. Not all structures can be resolved clearly with a school light microscope.

500

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Its projection increases area available for absorption

• A root hair cell has a long projection increasing surface area for absorption. Xylem vessels are dead hollow cells joined into tubes, with strengthened lignified walls carrying water and supporting the plant. Phloem transports dissolved sugars through living tissue; its conducting cells work with companion cells. GCSE explanations should link each named feature to its role rather than give an unsupported list.

3

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It changes a cell’s specialized structures and role

• In a mature animal, cell division mainly supports repair and replacement. Differentiation and mitosis have different roles: division increases cell number, while differentiation changes the functional type. Cells in a growing root can continue producing new plant tissues because developing cells can still specialize.

8 cells

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Greater resolving power

• Choose the relation for the unknown: real size = image size/magnification, and image size = real size×magnification. Convert to the same length unit first. A stated scale bar continues to describe the particular image even if the displayed image is resized, provided the bar is resized with it.

4 μm

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

To reduce the chance of growing harmful human pathogens

• Sterilized dishes and media reduce unwanted microorganisms. Sterilizing an inoculating loop prevents it transferring contaminants. The lid is secured with small pieces of tape rather than sealed all around; the plate is stored upside down to reduce condensation falling onto the agar. School cultures are generally incubated at 25 °C to reduce the chance of growing harmful human pathogens.

400 cells

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

10 mm

• For a circular region, area = πr². Radius is half the diameter. State whether the reported area includes the disc or subtracts its area: use the same convention for every treatment. A bigger zone does not on its own prove that the substance will treat a particular infection in a person.

78.5 mm²

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

A gene is a section of DNA and a chromosome carries many genes

• Keep three levels separate: DNA is the chemical genetic material, a chromosome is an organized DNA-containing structure, and a gene is a section of DNA. A replicated chromosome has copied genetic material ready for division. Replication and the later distribution into daughter cells have different effects.

9 pairs

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

DNA replication · ⁨Replicação do DNA⁩

• Use three overall stages: growth and DNA copying, mitosis, then cell division. AQA does not require the named phases within mitosis at this point. Mitosis supports growth and development in multicellular organisms and repair or replacement in mature animals; it does not produce genetically varied haploid gametes.

24 cells

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Embryonic stem cells have broader differentiation potential than bone-marrow stem cells

• Therapeutic cloning produces an embryo with the patient’s genes, so its stem cells offer a genetic match and reduced rejection in the specification’s model. Potential applications include conditions such as diabetes or paralysis. These are potential benefits, not guaranteed cures. Viral transfer and ethical or religious objections must be considered with the evidence.

24 plants

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

A larger concentration difference

• A larger concentration difference produces a greater net diffusion rate under comparable conditions. Higher temperature increases particle motion, and a larger membrane surface area allows more transfer at once. A thinner exchange surface provides a shorter route, as developed in the exchange-surface case.

40 particles

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It gives a short diffusion path

• Villi give the small intestine a large absorbing area. Lungs have many alveoli with thin surfaces, a blood supply and ventilation. Fish gills provide a large exchange surface supplied with blood. Root hairs increase plant absorbing area, while leaves provide a large gas-exchange surface and short paths through their tissues.

2 per cm

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Initial mass

• Percentage change = (final−initial)/initial×100. Mean water-uptake rate compares an estimated water amount with elapsed time. These are different quantities: percentage change adjusts for starting mass, while a rate describes change per unit time. Plot a concentration series and estimate where the trend crosses zero rather than expecting every individual repeat to lie on one line.

0.01 g/min

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Net ion uptake into a cell with higher ion concentration

• Compare three processes. Diffusion gives net movement of particles down their gradient. Osmosis concerns water crossing a partially permeable membrane from dilute toward more concentrated solution. Active transport can move selected solutes against their gradient using respiratory energy. The same membrane can support more than one process for different substances.

0.02 mg/min

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It emulsifies lipids

• Absorption moves soluble products into blood or lymph. Thin exchange surfaces and a large surface area shorten diffusion paths and increase transfer. Enzyme activity and transport are different processes.

25 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Organ

• In the digestive system, organs including the stomach and small intestine work together to digest and absorb food. Within an organ, muscle tissue can move contents while glandular tissue releases substances. A list of levels becomes an explanation when each example is placed at the correct level.

100

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It creates smaller droplets and suitable alkaline conditions

• Bile is made in the liver and stored in the gall bladder. Its alkaline character helps neutralize stomach acid entering the small intestine. It emulsifies fat into small droplets, increasing surface area for lipase. Bile is not an enzyme. Digestion products can build new carbohydrates, proteins and lipids, and some glucose is used in respiration.

4

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Iodine changes to blue-black

• Keep the test and result paired. A negative iodine observation does not show that all carbohydrates are absent, because the test concerns starch. Qualitative colour observations can indicate presence under the test conditions; a precise concentration requires calibration and controlled measurements.

62.5 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

To test removed samples without changing the main reaction mixture

• Amylase breaks starch into sugars. In an iodine sampling method, the endpoint is reached when a sample no longer turns iodine blue-black. With a fixed starting amount and endpoint, 1/time gives a comparative rate proxy. This proxy is not an independently measured amount of product per second.

0.0125 1/s

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Pulmonary vein

• Air moves through trachea and bronchi to alveoli. Many alveoli provide a large area; thin walls, nearby capillaries and ventilation support gas exchange. Blood flow maintains concentration differences for oxygen entering blood and carbon dioxide leaving it. The natural resting rate is controlled by pacemaker cells in the right atrium; an artificial electrical pacemaker can correct some rhythm irregularities.

60 cm³/s

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

A very thin wall

• Use structure → effect → function. A capillary wall only one cell thick reduces diffusion distance. Arterial muscle and elastic tissue cope with and modify blood flow under pressure. Venous valves aid one-way flow, particularly when pressure is low. Direction defines artery versus vein, while exchange defines the key capillary role.

9

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Platelets

• A red-cell adaptation explains oxygen transport, not every blood function. White cells can engulf pathogens or produce antibodies and antitoxins, developed in infection teaching. Platelets are cell fragments involved in reducing blood loss through clots. Plasma and cells should be identified separately in an image or diagram.

5 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It holds a narrowed artery open

• A donor heart, or heart and lungs, can be transplanted for severe failure. Artificial hearts are sometimes used while a donor is awaited or to let the heart rest. Evaluate benefit against procedural risk, infection, rejection or long-term management where relevant. A device treating one mechanism is not automatically a treatment for all cardiovascular disease.

6 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Rates with a common denominator and interval

• An incidence comparison needs a population denominator and time period. A scatter diagram can show an association between two variables, but an association alone does not establish direction or cause. Selection, access to diagnosis, age and other factors can change recorded rates.

20 per 1,000

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Increased probability in relevant evidence

• Many diseases involve several interacting factors, including genetic ones. A causal mechanism is established for some risks, while other associations remain less well explained. Population consequences include illness, reduced quality of life, care demands and financial costs for families, communities and health systems.

2

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Invasion and possible spread

• Uncontrolled division is different from normal regulated growth, repair and replacement. Lifestyle risk factors and inherited genetic risk factors can contribute to cancer risk, often with several factors interacting. A diagram of spread is a model of a mechanism, not a clinical diagnosis from appearance.

4

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Palisade mesophyll · ⁨Mesófilo paliçádico⁩

• A tissue is defined by its cells and role, while the whole leaf is an organ. Light reaching palisade cells supports photosynthesis, and a short gas pathway through air spaces supports exchange. A vascular bundle contains distinct transport tissues; it is not one tube carrying every substance in the same way.

40 per mm²

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Increasing surrounding humidity

• Transpiration is water loss by evaporation from leaf surfaces, mainly through stomata after water evaporates from moist internal tissues. Guard cells control stomatal opening. Higher temperature and greater air movement generally increase loss; greater humidity reduces the water-vapour gradient. More light usually opens stomata, increasing loss under comparable conditions.

2 mm³/min

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Resistant variants survive and reproduce more successfully

• After vaccination, memory cells can support a faster secondary response. Antibiotic resistance arises through heritable variation and selection; an individual bacterium does not choose to become resistant because it needs to survive.

20

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Viruses reproduce inside host cells and can damage them

• A prevention must interrupt the stated transmission route. Safe food and clean water reduce ingestion of pathogens; hygiene can reduce contact transmission. Ventilation and limiting exposure can reduce some airborne transmission. Controlling a vector interrupts a different route. These measures reduce risk rather than prove that every infection has been prevented.

5 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Leaf discolouration can reduce photosynthesis and glucose production

• HIV spreads through sexual contact or exchange of body fluids such as blood, including shared needles. Tobacco mosaic virus, TMV, causes a mosaic pattern of leaf discolouration. Less effective photosynthetic tissue means less glucose production, reducing plant growth. A symptom describes an effect; it is not itself the mechanism of transmission.

25 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Barrier contraception

• Gonorrhoea spreads through sexual contact. Barrier contraception such as condoms reduces transmission risk, while appropriate antibiotic treatment targets the bacteria. Some strains are resistant to antibiotics; the historical use of penicillin does not imply that it will now treat every strain. A named symptom alone cannot prove which organism caused it.

2 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It reduces photosynthetic tissue and glucose supply

• Removing and destroying affected leaves can reduce infectious material. Appropriate fungicides are another specified control, but school work follows teacher-approved handling and disposal. A control aimed at a fungus is distinct from treating bacterial disease. The effect on growth is explained through leaf function rather than simply saying that spots look unhealthy.

75 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

The protist causes malaria and a mosquito acts as a vector

• Distinguish organism roles carefully. The mosquito is an animal carrier, whereas the disease-causing organism is a protist. A net can reduce opportunities for a mosquito to bite a person; removing suitable breeding conditions can reduce the number of vectors. Neither measure should be described as directly killing every protist already inside an infected person.

30 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Antitoxin production

• White blood cells defend against pathogens by phagocytosis, producing antibodies and producing antitoxins. In phagocytosis a cell engulfs and digests a pathogen. Antibodies bind to particular antigens associated with a pathogen; antitoxins neutralize toxins. Explain the target before choosing the mechanism: removing a bacterium and neutralizing its toxin are different actions.

70 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Rapid production of the correct antibodies

• When many people are immune, a pathogen has fewer opportunities to pass to susceptible hosts. This can reduce spread through the population. Distinguish a vaccinated proportion from guaranteed protection: immunity, exposure and effectiveness vary, and a single percentage does not prove that transmission has stopped.

75 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Viruses reproduce inside host cells, which must be protected

• Viruses reproduce inside host cells. A drug that interferes with reproduction must avoid unacceptable damage to the host’s own cells and tissues, which makes development difficult. This does not imply that no antiviral medicines exist: antiretroviral control of HIV is one example already studied.

75 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Reduce expectation-related bias in measurement

• Testing investigates toxicity, efficacy and dose. Initial clinical doses are low to check safety. Suitable patient comparisons can include a placebo; blinding helps prevent expectations affecting reported or assessed outcomes. Double-blind trials keep both participants and the relevant researchers unaware of allocation during measurement. Independent peer review examines the methods and evidence before conclusions are accepted.

60 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Combine antibody production with repeated division

• The hybridoma culture supplies antibodies that can be collected and purified. Explain the purpose of each stage: lymphocyte for a suitable antibody, tumour cell for division, selection for the desired binding specificity and cloning for consistent output. Specificity does not mean the antibody binds to every protein or always cures a disease.

16 cells

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Specific binding plus a detectable linked label

• In a supplied cancer-treatment model, antibodies bind an antigen on cancer cells and carry a radioactive substance, a toxic drug or a chemical that stops growth and division. Targeting can reduce effects on other cells, but side effects may still occur. Evaluate usefulness through specificity, measured effects, harm and practical or ethical constraints rather than claiming a guaranteed cure.

35 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Less material for amino acids and proteins can restrict growth

• Magnesium is needed for chlorophyll production. A shortage can cause chlorosis, or yellowing, which reduces effective light absorption for photosynthesis. Distinguish a pest, a pathogen and a nutrient shortage: an insect is not a mineral deficiency, and adding nitrate does not directly eliminate a virus.

40 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Its antibody binds a particular target antigen

• The specification identifies gardening manuals or websites, laboratory identification of pathogens and test kits containing monoclonal antibodies as methods of identification. A specific antibody binds an appropriate target associated with a pathogen. Interpretation still requires valid controls and attention to the kit’s stated target and limitations.

60 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

An antibacterial substance produced by the plant

• Mechanical adaptations include thorns and hairs that discourage feeding, leaves that droop or curl when touched, and mimicry that can deter animals. Explain the consequence of each feature: a thorn affects contact or feeding, while an antibacterial substance affects bacteria. No single defence protects a plant against every threat.

20 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Another factor may now limit the rate

• Change only one factor when testing a limiting factor. At low light, extra light may increase rate. At a plateau, the changed factor is no longer the main limit in that range; the graph alone does not identify which other factor is limiting.

3 cm³/min

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

To reduce gas-volume changes unrelated to respiration

• Anaerobic respiration releases less energy per glucose than aerobic respiration. In human muscles it produces lactic acid; in yeast it produces ethanol and carbon dioxide. Breathing supplies oxygen but is not itself respiration.

0.1 cm³/min/g

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It transfers energy to drive the endothermic reaction

• Light supplies energy rather than being a material reactant with a mass in the equation. Carbon dioxide supplies carbon for glucose; water is also required and oxygen is released. Photosynthesis and respiration are different processes. Plants respire continuously in living cells, even when no light is available for photosynthesis.

18 molecules

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Bubble sizes can differ

• In required practical 6, an aquatic organism such as pondweed supplies an observable oxygen-output estimate. Gas volume divided by time is usually a better measure than bubble count when bubble sizes vary. A graph needs the varied factor on the horizontal axis, rate on the vertical axis and a consistent scale with units. A plateau means the changed factor no longer increases rate under those conditions.

0.6 cm³/min

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Reduces it to one quarter

• For the ideal point-source model, light intensity is proportional to 1/distance². Doubling distance makes intensity one quarter, not one half. Real lamp geometry and reflections can depart from this approximation. A greenhouse decision compares added revenue with added lighting, heating or carbon dioxide costs; maximum photosynthesis rate need not give maximum profit.

16 relative units

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

They supply nitrogen needed to form amino acids

• Storage, structure and energy transfer are separate roles. Starch is insoluble, so it can be stored without behaving like an equivalent amount of dissolved glucose. Cellulose is structural. Nitrate supplies needed nitrogen for amino acids; sunlight alone does not supply every element a growing plant needs.

30 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Ethanol and carbon dioxide

• Anaerobic respiration in muscle is glucose → lactic acid. Oxidation is incomplete, so much less energy is transferred than in aerobic respiration. In plant and yeast cells, anaerobic respiration is glucose → ethanol + carbon dioxide. Yeast fermentation is economically useful: carbon dioxide helps bread dough rise, and ethanol is used in alcoholic-drink manufacture.

4 cm³/min

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

To help deliver more oxygen for increased muscle energy demand

• During long periods of vigorous activity muscles become fatigued and stop contracting efficiently. Breathing can remain elevated during recovery as extra oxygen is needed. Distinguish rate from volume: breaths per minute and volume per breath are separate quantities, so both can affect the volume of air moved per minute.

10.8 L/min

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

The liver

• Explain the sequence using location and transport: muscle production, blood movement, liver processing and continued oxygen demand. The examination model supports explaining raised breathing during recovery. It does not imply that all oxygen consumed during exercise was absent or that every recovery process is the same chemical reaction.

0.9 L

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It includes both molecule synthesis and breakdown

• In plants, glucose and nitrate ions provide materials for amino-acid production. Metabolism also includes respiration and the breakdown of excess proteins to form urea for excretion. Match each molecule to its role rather than treating every metabolic reaction as digestion or every product as an energy store. Urea formation and urea excretion are related but distinct processes.

27 molecules

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Increased insulin action

• When blood glucose is high, insulin helps increase glucose uptake and storage as glycogen. When it is low, glucagon supports release of glucose from stores. These responses are coordinated, not identical effects of two hormones.

25 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

An effector

• Receptors detect stimuli, or changes. A coordination centre such as the brain, spinal cord or pancreas receives and processes information. Effectors are muscles or glands that produce a response restoring suitable levels. A receptor detects a change; it is not necessarily the structure producing the corrective action.

0.6 °C

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Receptor → sensory neurone → relay neurone → motor neurone → effector

• A reflex pathway includes a sensory neurone carrying information from a receptor, a relay neurone in the CNS and a motor neurone carrying information to an effector. At a synapse a chemical messenger crosses the small junction between neurones and triggers a new electrical impulse in the next cell. Reflexes are automatic and rapid and do not involve the conscious part of the brain, helping protect the body from harm.

26 ms

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It can allow anticipation instead of response to the actual release

• The chosen factor must change while other relevant conditions stay comparable. Keep the starting ruler position, hand position, catching method and instructions consistent. Avoid advance cues to the release. Repeated trials reduce the influence of random variation; a planned order can reduce practice or fatigue effects. A shorter drop distance generally indicates a quicker catch in the same method.

19 cm

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Cerebellum

• Use a diagram’s orientation to locate a region rather than assuming every picture has the same left/right view. The large outer cerebral region, the smaller cerebellum towards the back and the medulla linking to the spinal cord are distinct. A function can involve connections between regions; naming a region does not imply that it acts in isolation.

15 cards

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Complex interconnected and delicate regions complicate interpretation and intervention

• The brain is complex and delicate. Regions are interconnected, damage may affect more than one pathway and invasive procedures can cause harm. Evaluating a procedure weighs the expected information or treatment benefit against risks, uncertainty and ethical constraints. Agreement between different kinds of evidence can strengthen a conclusion without eliminating every limitation.

75 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Retina

• In dim light the iris allows a larger pupil, admitting more light; in bright light it reduces the opening. This is different from accommodation, which changes lens shape for focusing. Ciliary muscles and suspensory ligaments control lens shape. Correct diagram labels must distinguish a boundary, an opening, a transparent structure and a nerve.

4

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Ciliary muscles contract, ligaments loosen, lens thickens

• The lens does not actively pull itself into shape like a muscle. Explain the mechanical connection: ciliary-muscle action changes tension in the suspensory ligaments, allowing or pulling the elastic lens into the appropriate shape. A change in pupil size alone does not supply the required accommodation explanation.

3.5 mm

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

A diverging lens

• Interpret the ray diagram using the position of the retina and focus, then the effect of the external lens. The specification also identifies hard and soft contact lenses, laser surgery changing corneal shape and a replacement lens in the eye. These are correction technologies; choosing between them needs individual professional assessment rather than a classroom rule.

3 mm

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Vasoconstriction, stopped sweating and shivering

• When temperature is too low, those blood vessels constrict, called vasoconstriction, sweating stops and skeletal muscles contract repeatedly in shivering. These are coordinated responses rather than conscious choices alone. The specification connects hot-condition responses with transfer of energy from skin to the environment; the separate Higher lesson explains each mechanism in a stated context.

37.15 °C

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Evaporation requires energy transferred from the skin

• Vasoconstriction reduces blood flow near the skin surface and therefore reduces energy loss there. Stopping sweating avoids further evaporative cooling. Shivering is repeated skeletal-muscle contraction; increased muscle activity and respiration transfer more energy, helping warm the body. Blood is diverted from surface vessels rather than all circulation stopping.

0.2 g/min

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Gland → blood → target organ

• Locate the pituitary below the brain, thyroid in the neck, adrenal glands above the kidneys and pancreas in the abdomen. Ovaries lie in the pelvis and testes in the scrotum. These positions help identify glands on a body diagram; a gland’s position is not the location of every target it affects. The term master gland describes the pituitary’s coordinating role, not production of every hormone.

6 cm/s

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Target cells respond inadequately to insulin

• In the specified Type 1 diabetes model, the pancreas produces insufficient insulin and insulin injections replace the missing hormone. In Type 2, cells no longer respond adequately to insulin; the specification describes carbohydrate-controlled diet and exercise as management principles and obesity as a risk factor. These are course comparisons, not individualized treatment plans or a claim that every person has the same management needs.

25 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Glucagon promotes conversion of glycogen to glucose

• Trace two separate pathways: high glucose → insulin → lower glucose, and low glucose → glucagon → higher glucose. Both respond to the regulated variable. Do not say that glucagon and insulin simply cancel each other at all times, or that the system always holds one perfectly unchanging number.

25 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It is selectively reabsorbed

• Kidneys produce urine by filtering blood and selectively reabsorbing useful substances, including glucose, some ions and water. A substance in the initial filtrate is not automatically a waste product. The final composition depends on what is reabsorbed. Detailed nephron structure and other urinary-system anatomy are not required by this GCSE section.

7 units

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

More ADH and more water reabsorption

• When blood is too concentrated, the pituitary releases more ADH. ADH increases the permeability of kidney tubules to water, so more water is reabsorbed into blood. Less water remains in urine. As blood returns towards suitable concentration, the stimulus for ADH release decreases: negative feedback opposes the original disturbance.

6 units

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Its concentration difference across a permeable membrane

• Dialysis needs repeated treatment and imposes time and practical burdens. A successful kidney transplant can restore continuing kidney function, but needs a suitable donor, surgery and management of rejection. Compare risks, availability, lifestyle effects and evidence of benefit. Neither route should be presented as suitable for every individual or as a guaranteed cure.

75 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

LH

• FSH causes an egg to mature in an ovary. LH stimulates its release. Oestrogen and progesterone are involved in maintaining the uterus lining. An egg matures before it is released; ovulation is not fertilization or menstruation. Both-tier teaching requires these roles; the hormone interactions and graph analysis are separately Higher Tier.

50 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Falling progesterone support

• Read the supplied curves for the same time interval. Identify a hormone peak, connect it with the specified effect and explain an inhibition or stimulation arrow. Do not describe every increase as negative feedback: stimulation of the LH surge differs from inhibition of FSH. The simplified cycle model does not determine an individual’s cycle dates.

4

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It prevents sperm reaching an egg

• Intrauterine methods include hormone-releasing devices and non-hormonal copper devices. The acquired specification mentions prevention of implantation; the NHS reference explains copper’s main effect on sperm survival and fertilisation, with a possible additional implantation effect. Distinguish pregnancy prevention from protection against sexually transmitted infections. Evaluate use requirements, reversibility, evidence and values without inventing universal success rates.

2 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Egg maturation → collection → laboratory fertilisation → embryo development → transfer

• The acquired specification describes transfer of one or two tiny embryos. This is its teaching sequence, not a current clinical recommendation about embryo number. Treatment can be physically and emotionally stressful, success is uncertain and multiple births can carry risks to mother and babies. Evaluate benefits and risks using the stated evidence and perspectives rather than promise a guaranteed baby.

20 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Thyroxine

• A supplied thyroxine control diagram may show low thyroxine stimulating pituitary signalling to the thyroid, followed by thyroxine release. Raised thyroxine then reduces the stimulating signal. Explain how that opposes the initial fall. Do not assign the same negative-feedback sequence to every adrenaline event merely because both substances are hormones.

20 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Greater elongation on the shaded side makes it curve

• Roots and shoots respond differently. In a horizontal root, more auxin on the lower side inhibits elongation relative to the upper side, so the root bends downwards. In a shoot, greater lower-side elongation bends it upwards. Explain the growth difference rather than claim that gravity pulls all the cells into a new shape.

4 mm

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Initiating seed germination

• Distinguish a hormone effect from the conditions needed for the response. A viable seed still needs suitable environmental conditions. A fruit-ripening comparison needs a matched variety, maturity and observation period. A greater observed response in one treatment does not prove that every species or developmental stage behaves identically.

70 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Controlling fruit ripening in storage and transport

• A weed-killer application can change plant diversity and affect organisms depending on those plants. Evaluate intended crop benefits alongside non-target effects, biodiversity and the stated treatment conditions. A rooting comparison measures root formation, while a fruit-size comparison needs dimensions or mass; neither is automatically evidence for the other hormone uses.

75 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Each fertilization has probability one quarter of aa under this model

• In a simple monohybrid cross Aa × Aa, gametes carry A or a. Combining independent gametes gives AA, Aa, Aa and aa. The predicted probabilities describe many possible fertilizations, not a fixed order of children.

50 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Fusion of gametes

• Asexual reproduction uses one parent without fusion of gametes. There is no mixing of information from two parents; mitosis produces genetically identical offspring called clones in the school model. A clone can still grow differently in a different environment. Genetic identity is not a promise of identical height, health or every visible feature.

60 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

12

• Fusion of two gametes restores the normal number of chromosomes in the new cell. The new cell divides by mitosis, increasing the number of cells. As the embryo develops, cells differentiate and become specialised. Copying DNA before division does not mean the final gametes keep two chromosome sets.

16 chromosomes

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Inherited variation may improve survival of some offspring

• Asexual reproduction needs only one parent, avoids finding a mate and can produce many identical offspring quickly when conditions are favourable. Shared inherited susceptibility can become a disadvantage if conditions change. Malaria parasites reproduce asexually in the human host and sexually in the mosquito. Many fungi use asexual spores but also sexual reproduction. Strawberries can form runners and seeds; daffodils can divide bulbs as well as form seeds.

21 plants

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

The entire genetic material

• Studying the human genome helps researchers search for genes linked to disease, understand inherited disorders and investigate treatments. Comparing inherited DNA patterns also helps trace human migration in the past. A statistical link is not proof that a gene alone determines a person’s future health; many characteristics involve several genes and environmental influences.

15 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

The base attached to the sugar

• In the specified simple model, a sequence of three bases codes for a particular amino acid. The order of bases controls the order in which amino acids are assembled into a protein. Moving the same letters into a different order can change the information. Complementary pairing and the simple synthesis mechanism belong to the Higher lesson, so do not demand those details in a common-tier task.

12 groups

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It may change whether a gene is expressed

• A change in coding DNA can change the amino-acid sequence and therefore folding. An enzyme’s active site may no longer fit its substrate, or a structural protein may lose strength. Most mutations do not change the protein, or change it too little to alter its appearance or function. Non-coding DNA can control whether genes are switched on or off; variants there may affect expression without changing the coded amino-acid sequence.

5 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Heterozygous with the dominant phenotype

• A gamete carries one allele from the pair. A supplied Punnett square combines one allele from each parent. Its four boxes show equally likely combinations when the prompt gives equally likely gametes, not four children who must be born in that exact pattern. The specification names mouse fur colour and human red–green colour blindness as examples of genetic control; use a supplied inheritance key and do not assume both follow an identical autosomal cross. Most phenotype features involve multiple genes, often interacting with the environment, so the simple model has a defined scope.

60 offspring

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Both parents carry a recessive allele

• Each box combines one allele from each parent: AA, Aa, Aa and aa. State genotype and phenotype probabilities separately. The inference depends on the stated model: one gene, complete dominance and no new mutation. Do not apply it unchanged to characteristics controlled by many genes or to a scenario with incomplete dominance.

45 offspring

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Ff

• For a supplied Ff×Ff grid, the expected outcomes are FF, Ff, Ff and ff. Each offspring has a 1/4 chance of ff, a 1/2 chance of being a carrier and a 3/4 chance of not expressing the disorder in this model. Not expressing the disorder is not the same as not carrying its allele. Use the prompt’s explicit allele key; letter choice alone does not define dominance.

90 offspring

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

46

• Combining X with X gives XX; combining X with Y gives XY. A cross with egg labels X and X and sperm labels X and Y has two XX and two XY boxes. Expected ratio is 1:1 and probability is 1/2 for each outcome. This is the GCSE chromosome-inheritance model, not a complete account of human sex development or gender.

75 outcomes

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Different developmental environments

• Mutations occur continuously. Most do not affect the phenotype, some influence it and very few determine a new phenotype in the specification’s account. A variant that gives an advantage after an environmental change can become more common through selection. The environment does not intentionally produce exactly the mutation an organism needs.

18 cm

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Its carriers leave more surviving offspring

• The theory explains living species evolving from simple early life forms over more than three billion years. Selection acts on an existing population with variation; it does not mean every individual changes during its lifetime. If two populations become sufficiently different that they cannot interbreed to produce fertile offspring, they form separate species in the specified model.

80 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Select suitable offspring and repeat over generations

• Useful and attractive characteristics are not necessarily the same. Repeatedly breeding closely related individuals can cause inbreeding, making some breeds more prone to disease or inherited defects. A narrow breeding population may reduce variation. Evaluate production benefits alongside health, welfare and resilience rather than treating one selected measurement as the whole organism’s value.

25 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Introducing a gene into a recipient organism

• Potential agricultural benefits include improved yield or reduced crop damage. Evaluation also considers effects on wild flowers, insects, gene movement and farming practices. Medical benefits include production of useful substances and research on inherited disorders. The specification records objections and questions about long-term effects; these are issues to evaluate with evidence, not proof that every engineered product has the same risks.

20 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It carries the selected gene into recipient cells

• A plasmid is a small DNA ring, not the human protein product. A vector carries the chosen gene; recipient cells use genetic information to make a product. A virus vector is not a requirement that all engineered organisms become diseased. The general stages are required at Higher Tier, without needing an advanced laboratory protocol or every enzyme name.

15 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

The adult body-cell donor

• In adult-cell cloning, remove the nucleus from an unfertilised egg and insert a nucleus from an adult body cell such as skin. An electric shock stimulates division into an embryo. When it forms a ball of cells, transfer it into a female’s womb. The specified embryo genetic-information comparison concerns the adult nuclear donor; the host supplies the developmental environment. Detailed mitochondrial inheritance is outside this GCSE account.

75 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

The inheritance mechanism was not yet understood

• Acceptance was gradual. The ideas challenged widespread beliefs about separate creation, available evidence was initially insufficient to convince many scientists, and the inheritance mechanism was not yet understood. Lamarck’s explanation relied mainly on changes acquired during an organism’s lifetime being inherited; this is not how inheritance operates in the vast majority of the specified examples. A study of creationism is not required.

50 years

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

They cannot interbreed to produce fertile offspring

• A population may become geographically separated. The groups experience different conditions and selection pressures, with inherited variation in each. Different variants leave more offspring, and differences accumulate over generations. If the groups can no longer interbreed to produce fertile offspring, they are separate species under the specified definition.

30 percentage points

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Similar behaviour of units and chromosomes during inheritance

• Scientists did not yet understand chromosomes and the molecular basis of inheritance, making the importance of his results difficult to recognise. In the late nineteenth century, chromosome behaviour during division was observed. Early in the twentieth century, similarities with Mendel’s units supported locating genes on chromosomes. Mid-twentieth-century work established DNA structure and how genes function. Many scientists contributed.

25 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

An inherited resistant variant becomes more common over generations

• Each line answers a different question. A fossil gives evidence of past organisms but usually cannot show their complete DNA. A resistance dataset can show population change over generations but is not a complete history of all life. Agreement between inheritance mechanisms, historical records and observed selection strengthens the explanation.

30 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

A preserved footprint

• Many early organisms were soft-bodied and left few traces. Geological processes have destroyed much of the evidence. The record is therefore incomplete, limiting certainty about exactly how life began. Fossils nevertheless reveal how much or little organisms have changed and support reconstructions of evolutionary relationships.

40 million years

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

No members of the species remain alive anywhere

• A small, fragmented population may be vulnerable to loss even when some individuals survive a disturbance. If mortality exceeds successful reproduction for long enough, the number can reach zero. A local disappearance is not global extinction unless the evidence shows no surviving population elsewhere. An unsuccessful survey alone does not establish that conclusion.

38 individuals

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Resistant bacteria survive and reproduce while susceptible ones are removed

• The specification calls for avoiding inappropriate antibiotic prescribing, including use against viral infections, restricting agricultural antibiotic use and completing prescribed treatment. Current NHS information likewise says to follow the healthcare professional’s directions. New antibiotic development is slow and expensive. The selection explanation must not say bacteria mutate deliberately because treatment was stopped or that every resistant infection has no treatment.

40 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Genus and species

• Improved microscopy revealed internal structures and biochemical analysis provided further relationship evidence. Woese’s three-domain system separates archaea, bacteria and eukaryota; eukaryota includes protists, fungi, plants and animals. The specification describes archaea using older primitive-bacteria wording and extreme habitats; treat archaea as a separate domain rather than all bacteria or a claim that every archaeon lives in an extreme habitat.

30 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Use a transect with fixed sampling distances

• Estimate total abundance by multiplying mean density by area, with consistent units. This assumes sampled areas represent the habitat. Patchiness and too few samples widen uncertainty.

12

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Non-living environmental conditions

• Interdependence means species rely on others for resources or services, including food, shelter, pollination and seed dispersal. Removing one species can affect many others. In a stable community, species and environmental factors are in balance and population sizes remain fairly constant, although short-term fluctuations can occur.

120 individuals

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Soil pH

• A change can favour one species while disadvantaging another. More of a factor is not always better: organisms have suitable ranges, and a limiting factor can change. A relationship between population count and temperature is an association unless other changes are considered or controlled.

6 plants

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Arrival of a new predator

• The effect can spread through interdependent populations. Fewer prey may later reduce predator numbers; less pollination can reduce seed production. Explain the immediate link before proposing indirect changes. Not every new species outcompetes all existing species, and the effect depends on resources and local conditions.

25 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Reduced leaf surface can reduce water loss in dry conditions

• Some organisms live in extreme temperature, pressure or salt concentrations and are called extremophiles. The specification includes bacteria living near deep-sea vents. Extreme is relative to the usual conditions for many organisms, not a statement that no life can function there. Adaptations do not guarantee survival under every change.

25 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Grass is eaten by the rabbit

• In a stable community, prey and predator numbers can rise and fall in cycles. More prey can support more predators after a delay; greater predation can reduce prey, followed by fewer predators when food is scarce. The pattern is a model affected by other food, disease, migration and environmental factors.

3 months

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Random representative quadrat positions

• Required practical 9 measures a common species and investigates a factor affecting its distribution. Measure the factor, such as light intensity, at comparable sampling locations. Random sampling estimates the wider population; a single gradient transect is not automatically representative of the whole habitat. Mean, median and mode describe different properties of the recorded counts.

480 plants

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Respiration · ⁨Respiração⁩

• Carbon can remain in organic stores, including fuels formed over long periods. Combustion releases carbon dioxide from carbon-containing fuels or biomass. Materials cycle between biotic and abiotic components and provide building blocks for later organisms. Energy transfers through the system rather than being recycled in the same way.

30 carbon units

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Condensation · ⁨Condensação⁩

• Freshwater supply supports plants and animals on land. Organisms take up water and later return it through processes including excretion, respiration and transpiration. The water cycle includes both abiotic stores and biological transfers. A diagram can simplify the system, but not all rainwater immediately travels through the same route.

150 water units

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

pH change divided by elapsed time

• Required practical 10 investigates the effect of temperature on fresh-milk decay rate by measuring pH change. Use teacher-approved fresh milk, reagents, controlled water baths and a consistent endpoint. The acquired AQA handbook models faster decay with lipase acting on fresh milk or cream made alkaline using sodium carbonate, with Cresol red changing from purple to yellow. Lipase produces fatty acids; natural microbial decay instead lowers pH through processes including lactic-acid production. These are different mechanisms.

0.2 pH units/min

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Comparable survey areas, seasons and methods

• Distribution is where organisms occur; abundance is how many occur. A geographic shift need not mean total population size increased. Evaluate whether records cover comparable seasons, sampling methods and areas. Competing species, dispersal barriers and habitat availability can alter the expected response to an abiotic change.

3 km/year

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Seven species with 60 individuals

• A species count is one useful measure, but an incomplete survey misses organisms and does not describe every aspect of diversity. The specification’s stability account is a mechanism to explain rather than a guarantee that every diverse ecosystem resists every disturbance. Habitat condition, population sizes and interactions also matter.

5 species

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

More algal growth → decomposition → lower oxygen

• Pollutants can kill plants and animals or change the conditions needed for survival, reducing biodiversity. Fertiliser runoff can stimulate excessive algal growth; subsequent microbial decomposition can reduce dissolved oxygen and affect aquatic animals. This mechanism differs from a toxic substance directly poisoning an organism.

37.5 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Habitat loss and potential carbon release

• Peat contains accumulated organic material. Decay or burning releases carbon dioxide into the atmosphere. Keeping peat intact helps retain that carbon store. The specification asks students to weigh cheap available compost and food-production needs against habitat conservation and reduced emissions. Alternative materials also require evidence about cost, performance and environmental impacts.

25 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Crop output compared with habitat loss

• The result depends on the replacement system, what happens to the wood and the time interval. A claim that every biofuel has no emissions ignores land-use change and production. Evaluate food, income and energy benefits alongside habitat, carbon and other environmental consequences using the supplied evidence.

30 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Long-term climate trend versus one day’s weather

• Scientific consensus on climate change draws on systematic reviews of many peer-reviewed publications, not one weather observation. Complex local outcomes can be uncertain or incomplete because interacting factors, future emissions and biological responses vary. Uncertainty about a particular population’s future does not erase the wider evidence for warming.

0.05 °C/year

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Breeding support plus suitable habitat protection

• Each measure has benefits and limitations. Breeding needs genetic diversity and suitable release conditions; habitat restoration takes time; land set aside for biodiversity may compete with production. Human interactions can be positive or negative depending on the action and its context. A justified evaluation weighs evidence and conflicting pressures rather than listing only advantages.

50 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Outside the microorganism

• Decomposers break down dead plants, animals and waste. They secrete enzymes into their surroundings; enzymes digest large molecules into small soluble products that diffuse into the microorganism. This extracellular digestion lets material from several levels return to the system through microbial activity and material cycling.

4 transfers

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

At the bottom

• The pyramid is a diagram of a defined sample or estimate, not the physical shape of an ecosystem. Equal bar heights allow width to represent relative amount. Biomass and energy are related but are not the same quantity; do not label a kilogram dataset in joules. Organism numbers also require different data.

5 cm

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Passing unabsorbed food as faeces

• Not all ingested material is absorbed; some is egested as faeces. Absorbed material can be lost as respiration products, including carbon dioxide and water, or in excretion such as water and urea. Much glucose is used in respiration rather than retained as growth. Biomass available to higher consumers consequently decreases, helping explain smaller supported populations in a stated chain.

12 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Population size and access to food

• Sustainable responses need to maintain production without exhausting the conditions that support it. Greater output can help, but inaccessible or unaffordable food does not solve every shortage. A shift towards resource-demanding foods changes how land and feed are used. Use the supplied context instead of assuming one response fits every country.

3 units/person

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

It does not by itself measure animal welfare

• Higher growth or feed efficiency can support production, but limiting movement can raise animal-welfare concerns. Heating and maintaining facilities have costs and environmental impacts. Disease risk and health depend on management. Evaluate benefits, burdens and ethical objections with supplied evidence rather than presenting confinement as automatically desirable.

20 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Allow smaller fish to escape and potentially breed

• Conservation needs evidence about population trends, recruitment and actual removals. A quota alone does not guarantee sustainability if it is too high, ignored or combined with other pressures. Bigger mesh is not a universal solution for every species; bycatch and habitat effects also matter when information is supplied.

760 fish

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

Aerobic growth on glucose syrup

• Genetically modified bacteria can produce human insulin, which is harvested and purified for medical use. GM crops can increase useful output or nutritional value; golden rice is the specified nutritional example. These approaches connect genetic information with practical production but still need evidence about yield, quality, cost and environmental effects.

80 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.