Combined Science A (Gateway) · OCR J250 · Biology Paper 8 · Higher · June 2023
Which is a true statement about artificial classification?
A It is based on the observation of only one or a few characteristics.
B It involves the use of DNA sequencing.
C It relies on the use of phylogenetics.
D It uses the fossil record to link common ancestors.
[1]
The graph shows the changing population of one species in a habitat.
Predict the years when this species had the highest availability of their food source.
A Between 1980 and 1990
B Between 1990 and 2000
C Between 2000 and 2010
D Between 2010 and 2020
[1]
Which process in the water cycle returns water to the land from the atmosphere?
A Condensation
B Evaporation
C Precipitation
D Transpiration
[1]
Which would help to maintain biodiversity in the rainforest?
A Building large hotels for ecotourism in the rainforest
B International agreements to reduce climate change
C Making it legal to remove large areas of forest for wood
D Using large areas of forest to grow crops
[1]
Which sub-cellular structure from a prokaryotic cell is used in genetic engineering?
A Mitochondrion
B Nucleus
C Plasmid
D Ribosome
[1]
Lions hunt and eat antelopes.
Which row correctly describes lions in this relationship?
| Type of factor | Type of relationship | |
| A | abiotic | predator |
| B | abiotic | prey |
| C | biotic | predator |
| D | biotic | prey |
[1]
There are practical and ethical issues when using gene therapy to treat people.
Which statement is only a practical consideration with no ethical issues?
A Choosing which person should benefit from the treatment.
B How to insert the modified allele into a target cell.
C Religious beliefs of the patient.
D Who should pay for the treatment.
[1]
A stent is a small wire structure. It is placed inside the artery that supplies the heart muscle with
Why would someone need a stent fitting?
A A high-fat diet has resulted in fatty deposits inside their arteries.
B Drinking too much alcohol has caused cirrhosis.
C Lack of exercise has reduced the strength of their heart muscles.
D Smoking has damaged the blood vessels in their lungs.
[1]
What is the function of restriction enzymes in genetic engineering?
A To act as a vector and carry the DNA into the host.
B To cut the required gene from the DNA.
C To identify which cells have taken up the gene.
D To stick the gene into the DNA of the host.
[1]
A gardener grows a species of plant that has either red or white flowers. The colour of the flowers is controlled by a single pair of alleles, R and r.
The gardener crosses a plant that is homozygous for red flowers with a plant that is homozygous for white flowers. The diagram shows the results.
Explain why the offspring in the diagram are all red.
[2]
The offspring are all heterozygous for flower colour.
What is meant by the term heterozygous ?
[1]
The gardener crosses one of these offspring plants with a plant that is homozygous for white flowers.
Predict the probability that the next generation of plants will have white flowers.
Complete the genetic diagram to explain your answer.
[3]
The gardener grows another species of plant that can produce flowers of five different colours.
The gardener counts the number of plants for each flower colour.
The graph shows their results.
The gardener counted 97 plants.
Calculate the percentage of these plants that have blue flowers.
Give your answer to the nearest whole number.
[3]
What evidence is there in the graph that flower colour is an example of discontinuous variation in this species?
[1]
The male gametes of a plant are called pollen.
The sentences in the text box are about pollen. There are two words in the sentences that are not correct.
Pollen cells are haploid. This means that the pollen cells of a plant have twice
the number of chromosomes as the leaf cells of the plant.
Pollen cells are formed by a type of cell division called mitosis.
[2]
The diagram shows the four main components of the blood.
Draw lines to connect each letter to the component that they are labelling. Then draw lines from each component to their correct function.
Two lines have been drawn for you.
Letter Component Function
[3]
White blood cells are adapted to their function.
Explain two adaptations of white blood cells.
[2]
Read the information in the text box.
Prevent the spread of HIV
• Use protection during sexual intercourse
• Don’t share needles to inject drugs
• Avoid contact with blood from an infected person
• Get tested
Use your knowledge of HIV as a communicable disease to answer these questions.
Suggest how testing will help prevent the spread of HIV.
[1]
13* The pH of a soil will affect the crops that grow in the soil. When the soil pH is suitable, more crops will grow. This results in a higher yield (mass of crops).
The table shows data about the yield of four different crops, A, B, C and D, when grown in soils of different pH.
| pH range | Yield as a percentage of the highest yield obtained (%) | |||
| of soil | crop A | crop B | crop C | crop D |
| 4 – 4.9 | 25 | 3 | 14 | 65 |
| 5 – 5.9 | 74 | 8 | 34 | 75 |
| 6 – 6.9 | 100 | 98 | 100 | 100 |
A farmer measures the pH of the soil in their field. The soil is pH 4.5.
Which crop should the farmer grow in the field?
Explain your choice and give reasons why pH 4.5 prevents growth in some crops. Include ideas about enzymes and their function in plants.
[6]
A student investigates the population of snails in a habitat.
This is the method they follow:
• Mark out a grid 2 m × 2 m: each square of the grid is 0.25 m2.
• Write numbers 1 to 16 on pieces of paper and put them in a bag.
• Take one piece of paper out of the bag to select the square number.
• Record the number of snails in that square.
• Choose three more squares in the same way.
Why does the student use the pieces of paper to choose the squares in the grid?
[1]
The diagram shows the grid they use and the number of snails in the four squares they
Each square has an area of 0.25 m2. The total area of the habitat is 900 m2. (i)
Estimate the population of snails in the habitat.
Estimated population =........ snails
[2]
The student thinks the estimate is much larger than they would expect.
Suggest two ways the student could improve their investigation to get a more accurate estimate.
[2]
The student uses a transect to investigate the plants in the habitat.
Explain how to use a transect to investigate the distribution of different plant species in a habitat.
[4]
The picture is of a sword-billed hummingbird feeding on a flower.
• The hummingbird feeds on nectar from the flower.
• The flower benefits because the hummingbird transfers pollen from one flower to the next.
• This helps the flower to reproduce and develop seeds.
What word describes the interdependence between the hummingbird and the flower?
[1]
The long beak of the sword-billed hummingbird is an adaptation that helps the bird to feed. The bird’s ancestors had shorter beaks.
Explain how the sword-billed hummingbird may have evolved to have a long beak. Include ideas about natural selection.
[3]
A student investigates the effect of antibiotics on the growth of bacteria.
This is the method they follow:
• Place discs of paper containing different antibiotics on an agar plate containing bacteria.
• Leave the agar plate in a warm place.
• Observe the growth of the bacteria after three days.
The diagram shows their results. Clear zones around the antibiotic discs show where the bacteria growth is inhibited.
What are the independent variable and the dependent variable for this investigation?
Independent variable........
Dependent variable........
[1]
Explain why the student uses a disc with no antibiotics on it.
[2]
Which antibiotic, A – E, is the most effective?
Explain your answer.
[2]
After the student has recorded their results the agar plates are destroyed.
Why should agar plates containing bacteria be destroyed?
[1]
Suggest how the student could develop their investigation to show the effect of antibiotic on the growth of different bacteria.
[2]
The paper as printed
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