OCR GCSE Combined Science B (21st Century) Paper 1 June 2019 question paper

Herring are a type of fish. They live in the North Sea.

The diagram shows a food web for the North Sea.

Draw lines to connect each organism, below, to its role in the food web.

Write down the names of the three animals in the food web that eat herring.

Biomass is passed along a food chain when organisms are eaten.

Biomass is made by photosynthesis.

Complete the word equation for photosynthesis.

The sentences describe photosynthesis.

Light is needed for the first / the second / both stage(s) of photosynthesis.

Photosynthesis is endothermic / exothermic / respiration because it uses energy from the Sun.

Since 1998 the fishing of herring from the North Sea has been described as sustainable.

Which statements are true for sustainable fishing of herring?

Tick (✓) two boxes.

Sarah is studying the cell cycle in a chicken embryo.

She makes a slide of some cells from the embryo. She looks at the slide using a light microscope.

Fig. 2.1 shows what she sees.

How many of the 20 visible cells are in mitosis in Fig. 2.1 ?

When making the slide Sarah added a coloured chemical called methylene blue.

Explain why.

Chicken embryos develop inside an egg with a hard shell.

Fig. 2.2 shows some structures in a chicken egg.

Suggest two ways that the gas exchange surface is similar in humans and chicken eggs.

Sarah and some of her friends discuss cellular respiration in the chicken embryo.

Who is correct?

Tick (✓) one box.

Sickle cell disease is an inherited condition.

Sickle cell disease is caused by a single gene. A person will only have sickle cell disease if they inherit a faulty allele of this gene from both parents.

Two parents do not have sickle cell disease. These parents can have a child that does have sickle cell disease.

Complete the Punnett square in Fig. 3.1 to explain how this is possible.

Use:

a to represent a sickle cell disease allele

A to represent a normal allele.

* Look at the differences in the red blood cells of people with and without sickle cell disease in Fig. 3.2.

Explain how normal red blood cells are adapted to carry oxygen and suggest why people with sickle cell disease often need to be given extra oxygen.

Red blood cells contain a protein called haemoglobin. Red blood cells are made from stem cells in the bone marrow.

The sentences below explain why only these stem cells can make haemoglobin.

Use words from the list to complete the sentences. Each word or phrase can be used once, more than once or not at all.

amino acids

carbohydrates

deleted

genes

not present

proteins

switched on

switched off

Every human body cell nucleus contains instructions to make........

These instructions are called........

In red blood stem cells the instructions give the order of........ needed to make haemoglobin.

Other body cells cannot make haemoglobin because the instructions are

........

In 2017 scientists claimed to have found a cure for sickle cell disease. The cure used stem cells. The stem cells were taken from a man’s bone marrow.

Which statement about stem cells from bone marrow is true?

Tick (✓) one box.

The scientists’ results were published in a peer-reviewed journal.

Which statements explain why we can have confidence in the reported results?

Tick (✓) two boxes.

The human heart beats continuously.

Diagrams A, B, C and D in Fig. 4.1 show stages in a heartbeat. The shading shows which chambers and arteries contain blood during each stage.

The diagrams are not in the correct order.

Write down the correct order of the stages in a heartbeat. One has been done for you.

A student writes a plan to investigate the effect of exercise on pulse rate and recovery rate.

Method:

1. Measure the resting pulse rate by placing two fingers against the wrist (do not use your thumb) and count the number of beats in 10 seconds.

2. Step up and down on the step 30 times per minute, for 3 minutes.

3. Stop after 3 minutes and immediately measure the pulse.

4. Measure the pulse again every 30 s.

The student is correct that the thumb should not be used to take the pulse.

Suggest why.

In step 1 the student plans to count the number of beats.

How should the student calculate the resting pulse rate per minute from the count?

Describe how the student can work out the recovery rate from her measurements.

The student’s results are shown in Table 4.2.

Plot the results from Table 4.2 on the graph and draw a curve of best fit.

The student’s resting pulse rate was 72 bpm.

She uses Table 4.3 to decide her fitness rating.

Write down her fitness rating.

From these results, how confident should the student be about her fitness rating?

Explain your answer.

This question is about evolution.

Scientists think all animals with backbones evolved from a common ancestor.

The diagram shows the likely evolutionary relationships between some groups of animals with backbones.

Here are some statements about the evolutionary relationships shown in the diagram.

Tick (✓) true or false for each statement.

Evolution can result in the formation of new species.

Explain why although horses and donkeys can breed they are classed as two different species.

Influenza (flu) is a common human infection.

It is caused by a virus.

The poster in Fig. 6.1 teaches people how to prevent the flu virus spreading.

Draw lines to connect each part of the poster to why it is necessary.

Part of the poster
Why it is necessary

People can be given a vaccination to help protect them from flu.

Vaccination causes white blood cells in the body to make antibodies against the pathogen.

How else do white blood cells protect against pathogens?

Tick (✓) two boxes.

Flu vaccines cannot be given to very young babies.

Which two statements explain why vaccinating adults helps protect young babies from flu?

Tick (✓) two boxes.

A new flu vaccine is made every year. The vaccines contain proteins from the surface of the flu virus.

Fig. 6.2 shows the flu virus from 2018.

Fig. 6.3 shows the antibodies made by a person who had the vaccination in 2018.

The flu virus changes regularly.

Fig. 6.4 shows the flu virus from 2019.

Explain why the vaccine from 2018 would not protect you against the flu virus from 2019.

Use Fig. 6.2, Fig. 6.3 and Fig. 6.4 to help you.

In 2017 there was a flu epidemic in Australia. 170 000 people in Australia were infected. The population of Australia in 2017 was 25 000 000.

Calculate the percentage of the population of Australia infected with flu in 2017.

Give your answer to 1 decimal place.

Scientists used an electron microscope to look at a flu virus.

What are the advantages of electron microscopes over light microscopes?

Tick (✓) two boxes.

The virus is 0.1 m in diameter. It infects a human cell that is 50 m in diameter.

How many times bigger is the human cell than the virus?

There was a flu epidemic in 2009.

Use Fig. 6.5 to estimate the increase in pneumonia cases from 2008 to 2009.

Increase =........ people per 100 000

There is a positive correlation between having flu and having pneumonia.

Which graph, A, B, C or D, shows a positive correlation?

Tick (✓) one box.

Does a correlation between flu and pneumonia prove that having flu causes pneumonia?

Explain your answer.

Cellular respiration takes place in living cells.

In which parts of a cell do the reactions of cellular respiration take place?

Tick (✓) two boxes.

Which processes need energy from cellular respiration?

Tick (✓) two boxes.

All living cells produce hydrogen peroxide (H₂O₂) as a waste product.

The cells in potatoes contain an enzyme called catalase. It breaks down H₂O₂ to water and oxygen, this is the equation for the reaction that takes place.

Mia investigates the effect of H₂O₂ concentration on the rate of this reaction.

She writes out her method.

1. Put a peeled potato in a liquidiser with some water to make potato extract.

2. Dip a paper disc in the potato extract. The potato extract is a source of catalase.

3. Drop the paper disc into a test tube containing H₂O₂ solution.

4. Wait until the disc has sunk to the bottom.

5. Time how long it takes for the disc to rise to the surface of the H₂O₂.

This is a diagram of her apparatus.

Mia’s method lacks the detail needed for another scientist to reproduce her findings.

Suggest additional detail which would allow another student to follow the method exactly.

Bubbles form on the paper disc when it is in the H₂O₂ solution. This causes the disc to rise to the surface of the solution.

Mia thinks that if a disc rises more quickly, this means that the rate of reaction is faster.

Explain why she is correct.

The table shows Mia’s results.

Calculate the rate of reaction for 6.00% H₂O₂ solution.

Give your answer to 3 significant figures.

Rate =........ s^–1

Which conclusions are supported by the data in the table?

Tick (✓) two boxes.

Between 0.75% and 6.00% H₂O₂ the reaction rate increases by approximately 2.5 times.

Doubling the concentration of H₂O₂ halves the time taken for the disc to reach the surface.

Increasing the concentration of H₂O₂ decreases the rate of reaction.

Increasing the concentration of H₂O₂ increases the time taken for the disc to reach the surface.

The biggest difference in time taken for the paper disc to reach the surface is between 0.75 and 1.50% H₂O₂.

Describe what Mia could do to increase confidence in her data.