Edexcel GCSE Biology Paper 1 Higher June 2019 question paper 1BI0/1H

A student had solutions of four different foods labelled W, X, Y and Z.

Each solution was tested for starch and protein.

The colour of the solutions after the tests are shown in Figure 1.

Which solution contains starch but not protein?

Describe how a solution of food can be tested for reducing sugars.

Figure 2 shows a calorimeter.

Describe how this calorimeter can be used to find the energy content of 10 g of food.

A scientist obtained a mass of 0.0062 nanograms of DNA from a diploid human cell.

Calculate the mass of DNA the scientist should obtain from a haploid human cell.

Give your answer in picograms.

(1 nanogram = 1000 picograms)

A student used the method shown in Figure 3 to compare the mass of DNA extracted from strawberry fruit cells and from kiwi fruit cells.

crush the fruit cells in a buffer solution

filter to separate the soluble DNA from the cell fragments

State why ethanol is used.

State two variables the student needs to control when using this method to compare the mass of DNA from these two fruits.

The student repeated the experiment.

Give one reason why.

Mitosis and meiosis are processes that produce new cells.

Compare the outcomes of mitosis and meiosis.

Clostridium tetani is a bacterium that can be found in soil.

It causes the infection tetanus.

Children are vaccinated against tetanus.

Explain why these children do not get tetanus if the bacteria enter their body through a cut in the skin.

Colistin is an antibiotic used to treat infections in the bloodstream.

Some bacteria are resistant to Colistin.

Explain how these bacteria have become resistant to Colistin.

The effect of age on focusing distance was investigated.

Volunteers of different ages had their eyes tested.

Each volunteer was asked to read words from a book. The book was moved closer to their eyes.

When the words became out of focus, the distance was recorded.

Figure 4 shows the results.

Calculate the mean distance for the volunteers aged 50.

Give your answer to three significant figures.

Give one conclusion that can be made from the data in Figure 4.

Give two improvements that are needed in this investigation before a valid conclusion can be made.

Which part of the eye detects coloured light?

Figure 5 shows light rays entering the eye of a person with normal vision.

Describe how light rays are focused to give normal vision.

Figure 6 shows light rays entering the eye of a person with an eye defect and two lenses that can be used to correct eye defects.

Explain which lens would correct the eye defect shown in Figure 6.

Organisms can be classified by the five kingdom or three domain method.

What is the name of the domain that plants belong to?

Plant cells contain chloroplasts.

What happens in a chloroplast?

Give a reason why the three domain method of classification has been suggested.

Figure 7 shows a cyanobacterium magnified 50 000 times.

The line AB shows the diameter of the bacterial cell.

(Source: © The Christian Science Monitor)

Figure 7

Calculate the actual diameter of the cyanobacterium.

Give your answer in micrometres (µ m).

Bacterial cells contain plasmids.

Describe three other features of a bacterial cell.

Figure 8 shows a plasmid containing the human insulin gene.

Explain how the human insulin gene can be inserted into a plasmid.

Lactase is an enzyme that breaks down lactose into glucose and galactose.

A student made some alginate beads containing lactase.

The student added 10 beads to 20 cm³ of a solution of lactose, as shown in Figure 9.

The student timed how long it took for glucose to be produced.

The experiment was repeated using 15, 20 and 25 beads.

The results are shown in Figure 10.

What is the rate of reaction for 25 beads?

Explain the conclusion that can be made from these results.

Explain why the same volume of lactose solution was used for each test.

Devise a method to find the optimum temperature for the enzyme lactase.

Measles is a disease caused by a virus.

Describe the lytic pathway for a virus.

A measles infection can cause inflammation of the brain.

Figure 11 shows a brain.

Name the part of the brain labelled X.

The death rate from measles is 0.15%.

In 2015, 134 250 people died from measles.

Calculate the number of people infected with measles in 2015.

Give your answer in standard form.

Measles is prevented by immunisation.

State two reasons why people might not be immunised against measles.

The spread of measles is prevented by herd immunity.

Describe herd immunity.

LDL cholesterol is a type of cholesterol which increases the risk of heart disease.

Statins are drugs used to reduce LDL cholesterol levels.

Figure 12 shows the cholesterol levels in the blood of a man.

He started taking statins at the beginning of February and stopped taking them four months later.

Describe the effect of statins on LDL cholesterol levels in the blood.

Use data from the graph to support your answer.

Use evidence from the graph to explain why statins are usually prescribed as life-long medication.

Which data can be used to calculate the man’s BMI?

*(c) Gonorrhoea is a sexually transmitted bacterial infection.

Figure 13 shows the number of people diagnosed with gonorrhoea in the UK.

Explain how gonorrhoea is transmitted and how the number of people infected can be reduced.

Use data from the graph to justify why it is necessary to reduce the number of people infected.

Transcription and translation are stages in the synthesis of proteins.

Which enzyme is involved in the process of transcription?

Describe how a mutation in the non-coding region of the DNA can prevent a gene being transcribed.

A gene coding for a protein has two alleles.

Figure 14 shows the first 5 codons of an mRNA strand for these alleles.

Allele 1 – AUG CCA CAG GAG UUC

Allele 2 – AUG CCA GAG GAG UUC

Figure 14

Allele 2 has a mutation.

Figure 15 shows the key needed to predict the translated amino acid sequence of the protein.

Explain how the mutation in allele 2 could affect the functioning of this protein.

*(c) The inheritance of different alleles affects the phenotype of an individual.

A child is blood group O.

The child’s mother is blood group A and the child’s father is blood group B.

Explain how this child is blood group O.

Use the Punnett square and probability in your answer.

Figure 16 shows the number of neurones in the brain of different animals.

Calculate the difference between the number of neurones in the brain of the rat and the brain of the frog.

Give your answer in standard form.

Most neurones in the brain are unmyelinated whereas motor neurones are myelinated.

Explain why myelination is needed on motor neurones but not on neurones in the brain.

Figure 17 shows a sensory neurone.

Label the axon on Figure 17.

Describe the role of sensory neurones.

Explain how impulses are transmitted at synapses.