GCSE Biology Higher Paper 1
Covers Cell Structure and Transport, Cell Division and Stem Cells, Digestion and the Circulatory System and 9 more.
Questions
Question 1 [4 marks]
Respiration and Exercise
At rest, a person takes 16 breaths per minute, and each breath takes in 250 cm^3 of air, of which 4% is absorbed as oxygen into the blood.
Calculate the volume of oxygen absorbed into the blood per minute, in cm^3.
Question 2 [4 marks]
Photosynthesis
A student measures the volume of oxygen gas collected from pondweed using a gas syringe. In 5 minutes, 20 cm^3 of oxygen was collected.
Calculate the mean rate of photosynthesis in cm^3 of oxygen per minute, then calculate how long it would take to collect 50 cm^3 of oxygen at this rate.
Question 3 [4 marks]
Cell Structure and Transport
A student views a cheek cell using a light microscope.
The image of the cell measured on the photograph is 24 mm wide.
The actual width of the cheek cell is 60 micrometres.
Calculate the magnification of the image. Give your answer as a whole number.
Question 4 [4 marks]
Evolution and Natural Selection
In a polluted area, a population of moths was studied over 10 years. The percentage of dark-coloured moths increased from 20% to 80% of the population.
Calculate the percentage increase in the proportion of dark-coloured moths over the 10 years.
Question 5 [5 marks]
Cell Division and Stem Cells
Doctors are researching the use of stem cells to treat conditions such as paralysis caused by damage to the spinal cord.
Explain how stem cells could be used to treat this condition, and explain one risk associated with this type of treatment.
Question 6 [5 marks]
Pathogens and Communicable Disease
Explain why a new flu vaccine has to be developed and given to at-risk groups each year, rather than one flu vaccine giving lifelong protection.
Question 7 [5 marks]
Digestion and the Circulatory System
A student burned a 0.5 g sample of food beneath a boiling tube containing 50 cm^3 of water. The temperature of the water rose from 20 deg C to 44 deg C.
Using energy (J) = mass of water (g) x 4.2 x temperature rise (deg C), calculate the energy released per gram of food, in J/g.
Question 8 [5 marks]
Hormones and Homeostasis
A patient with an underactive thyroid gland is prescribed a starting dose of 50 micrograms of levothyroxine (a synthetic thyroxine) per day. After a blood test, the doctor increases the dose by 25%.
Calculate the patient's new daily dose, in micrograms, and state, in terms of negative feedback, why a patient with an underactive thyroid needs this medication at all.
Question 9 [6 marks]
Genetics and Inheritance
Embryos created by IVF can be screened for certain genetic disorders before being implanted in the mother, so that only unaffected embryos are chosen.
Evaluate the benefits and drawbacks of embryo screening for a serious inherited genetic disorder.
Question 10 [6 marks]
Human Defence Systems and Treating Disease
Monoclonal antibodies are identical antibodies produced from a single clone of cells.
Describe how monoclonal antibodies are produced, and explain one way they can be used, such as in pregnancy testing or in treating disease.
Question 11 [6 marks]
Ecosystems and Material Cycles
In a food chain, producers contain 12000 kJ of energy stored in biomass. The primary consumers that feed on them contain 1200 kJ of energy stored in biomass.
Calculate the percentage of energy transferred from producers to primary consumers, and explain three reasons why not all of the energy is transferred between these trophic levels.
Question 12 [6 marks]
The Nervous System and Reflexes
Explain, in terms of the lens and ciliary muscles, how the eye focuses on a near object rather than a distant object.
Model solutions
| Question 1[4 marks] | |
|---|---|
| Answer or working | Marks |
| volume of air per minute = 16 x 250 | M1 |
| 4000 cm^3 | A1 |
| oxygen absorbed = 4% of 4000 | M1 |
| 160 cm^3 | A1 |
| Final answer: 160 cm^3 of oxygen is absorbed into the blood per minute | |
| Question 2[4 marks] | |
|---|---|
| Answer or working | Marks |
| using rate = volume / time | M1 |
| substituting 20 / 5 | M1 |
| 4 cm^3 per minute | A1 |
| time = 50 / 4 = 12.5 minutes | A1independent |
| Final answer: Rate = 4 cm^3 of oxygen per minute; it would take 12.5 minutes to collect 50 cm^3 | |
| Question 3[4 marks] | |
|---|---|
| Answer or working | Marks |
| converting the actual width to the same units as the image: 60 micrometres = 0.06 mm | M1 |
| using magnification = image size / actual size | M1 |
| substituting 24 / 0.06 | M1 |
| magnification = x400 | A1 |
| Final answer: x400 | |
| Question 4[4 marks] | |
|---|---|
| Answer or working | Marks |
| finding the increase = 80 - 20 = 60 percentage points | M1 |
| using percentage change = (increase / original) x 100 | M1 |
| substituting (60/20) x 100 | M1 |
| a 300% increase | A1 |
| Final answer: 300% increase | |
| Question 5[5 marks] | |
|---|---|
| Answer or working | Marks |
| stem cells can differentiate into different types of specialised cell | B1 |
| stem cells could be used to grow new nerve cells to replace the damaged cells | B1 |
| the new cells could restore the connections needed for nerve signals to pass | B1 |
| a risk: transplanted stem cells could carry or transmit a viral infection | B1 |
| a further risk: the recipient's body may reject the transplanted cells, causing an immune response | B1 |
| Final answer: Stem cells could differentiate into new nerve cells to repair the spinal cord; risks include transmission of infection or rejection by the immune system | |
| Question 6[5 marks] | |
|---|---|
| Answer or working | Marks |
| the flu virus mutates (changes) frequently, causing its surface antigens to change (antigenic variation) | B1 |
| memory cells and antibodies from a previous infection or vaccination are specific to the old antigens | B1 |
| these memory cells/antibodies no longer recognise the new, changed antigens on the mutated virus | B1 |
| so a person is not immune to the new strain and can become infected/ill again | B1 |
| a new vaccine, matched to the currently circulating strain's antigens, must therefore be developed and given each year | B1 |
| Final answer: The flu virus mutates often, changing its surface antigens; old antibodies and memory cells no longer recognise the new antigens, so people are not immune to new strains, meaning a new vaccine matching the current strain is needed each year | |
| Question 7[5 marks] | |
|---|---|
| Answer or working | Marks |
| temperature rise = 44 - 20 = 24 deg C | M1 |
| substituting into energy = mass of water x 4.2 x temperature rise | M1 |
| energy released = 50 x 4.2 x 24 = 5040 J | M1 |
| energy per gram of food = 5040 / 0.5 = 10080 J/g | A1 |
| converting to 10.08 kJ/g (or equivalent to appropriate significant figures) | B1independent |
| Final answer: 5040 J released in total, equivalent to 10080 J/g (10.08 kJ/g) of food | |
| Question 8[5 marks] | |
|---|---|
| Answer or working | Marks |
| finding the increase = 25% of 50 | M1 |
| substituting 0.25 x 50 | M1 |
| 12.5 micrograms | A1 |
| a new dose of 50 + 12.5 = 62.5 micrograms | A1independent |
| an underactive thyroid gland not producing enough thyroxine naturally, so without medication the feedback system cannot raise thyroxine concentration to a normal level | B1 |
| Final answer: The dose increases by 12.5 micrograms to a new dose of 62.5 micrograms per day; medication is needed because the underactive thyroid cannot produce enough thyroxine naturally for the feedback system to correct | |
| Question 9[6 marks] | |
|---|---|
| Answer or working | Marks |
| benefit: parents who are known carriers of a serious genetic disorder can avoid having a child who is severely affected by (or who dies from) the condition | B1 |
| benefit: it can reduce the emotional and financial burden on a family, and on healthcare services, of caring for a severely affected child | B1 |
| drawback: the screening and IVF process is expensive, and is not available to (or affordable for) everyone | B1 |
| drawback: some people are concerned that screening embryos, and choosing not to implant an affected one, is a form of discrimination against people who already have that disorder or disability | B1 |
| drawback: there is a concern that if screening technology developed further, it could be used to select for characteristics that are not medical necessities, which raises further ethical concerns | B1 |
| an overall evaluation, e.g. many people judge screening for a serious, life-limiting disorder to be justified, even though wider or non-medical use of the technology remains ethically controversial | B1 |
| Final answer: Embryo screening can prevent a family having a child severely affected by a serious inherited disorder, reducing suffering and costs of care, but it is expensive and not available to all, and some see it as discriminatory towards people with the condition or a step towards selecting non-medical characteristics | |
| Question 10[6 marks] | |
|---|---|
| Answer or working | Marks |
| a mouse is stimulated with a chosen antigen to produce lymphocytes that make the specific antibody | B1 |
| these lymphocytes are fused with a tumour cell to produce a hybridoma cell | B1 |
| the hybridoma cell can divide repeatedly and produces the antibody | B1 |
| many hybridoma cells are cloned to produce a large number of identical cells producing the same antibody | B1 |
| identifying a specific use, such as monoclonal antibodies binding to the hormone found in urine during pregnancy, or binding only to antigens found on cancer cells so a drug can be delivered to them | B1 |
| explaining the outcome of that use, such as this binding causing a colour change on a pregnancy test stick, or delivering the drug specifically to the cancer cells while reducing damage to other, healthy cells | B1 |
| Final answer: Monoclonal antibodies are made by fusing an antibody-producing lymphocyte with a tumour cell to form a hybridoma that is cloned; they are used, for example, in pregnancy tests or to target drugs at cancer cells | |
| Question 11[6 marks] | |
|---|---|
| Answer or working | Marks |
| using percentage transferred = (energy in consumers / energy in producers) x 100 | M1 |
| substituting (1200/12000) x 100 | M1 |
| 10% | A1 |
| a reason: not all parts of the producer are eaten by the consumer, such as roots not being consumed | B1 |
| a reason: some absorbed material is not digested and is lost as waste (egested) | B1 |
| a reason: energy is lost as heat to the surroundings, especially from respiration, or is used for movement and other life processes rather than being stored as biomass | B1 |
| Final answer: 10% of the energy is transferred; energy is lost because not all of the producer is eaten, some is egested as waste, and much is lost as heat from respiration and other life processes | |
| Question 12[6 marks] | |
|---|---|
| Answer or working | Marks |
| to focus on a near object, the ciliary muscles contract | B1 |
| this reduces the tension in the suspensory ligaments (they become slack) | B1 |
| the lens, no longer being pulled taut, becomes fatter/more rounded, increasing its power to refract (bend) light | B1 |
| this greater refraction is needed to focus light from a nearby object (which diverges more) onto the retina | B1 |
| to focus on a distant object, the ciliary muscles instead relax and the suspensory ligaments become taut | B1 |
| this pulls the lens thin, reducing its power, which is enough to focus the more parallel light rays from a distant object | B1 |
| Final answer: For a near object, ciliary muscles contract, slackening the suspensory ligaments so the lens becomes fatter and more powerful, refracting light strongly enough to focus it on the retina; for a distant object the ciliary muscles relax, the ligaments pull the lens thin, and its lower power is enough to focus the more parallel light | |