OCR GCSE Combined Science B (21st Century) Paper 1 June 2018 question paper

The diagrams in the table show different types of cells.

Identify the type of cell shown in each diagram.

Tick one box in each row.

Hormones control many processes in the human body.

The menstrual cycle is controlled by hormones.

The graph in Fig. 2.1 shows changes in the levels of these hormones during the menstrual cycle when an egg is not fertilised.

Look at the graph in Fig. 2.1.

Describe how the hormone levels change after an egg has been released.

Contraceptive pills contain hormones that can prevent pregnancy.

Which statement gives the best explanation of how the hormones in a contraceptive pill prevent pregnancy?

Tick (✓) one box.

Give one disadvantage of relying only on a hormone contraceptive pill to prevent pregnancy.

This question is about the genome.

Which two statements about the genome are correct?

Tick (✓) two boxes.

A student makes some notes about genomes.

1. The genome is made from DNA.

2. Genes are sections of DNA.

3. DNA is wound into a triple helix.

4. DNA is a polymer.

5. DNA is made from amino acids.

The teacher spots some mistakes.

Write down the numbers of the two sentences that contain mistakes.

The sequence of bases in a whole human genome can be worked out.

It cost £1 000 000 000 to sequence a human genome in 2003. It can now be done for £1000.

How many times more expensive was it in 2003 than it is now to sequence a human genome?

10⁴ 10⁵ 10⁶ 10⁷

Four students talk about genetic testing.

Which student suggests that only a few diseases are caused by single genes?

Tick (✓) one box.

Which student suggests a possible extra health risk caused by having a genetic test?

Tick (✓) one box.

Which student has forgotten that the genome and the environment both affect our features?

Tick (✓) one box.

A student wants to investigate the effect of different sugars on the rate of anaerobic cellular respiration in yeast.

They use the apparatus shown in the diagram for their investigation.

A gas is produced by the yeast during anaerobic cellular respiration.

What is the name of the gas produced by the yeast?

Tick (✓) one box.

The gas is collected in the gas syringe.

Explain why using a gas syringe is a better technique to use than counting the bubbles of gas produced.

The student does two experiments in their investigation:

• one using yeast in a sugar solution containing glucose

• one using yeast in a sugar solution containing sucrose.

The student plots a graph of the results.

Which conclusion could be made from the graph?

Tick (✓) one box.

How much gas had been collected after 30 minutes from the yeast in glucose solution?

The student makes some suggestions to explain the pattern of results for yeast in glucose solution after 30 minutes.

Which statements give the two best explanations?

Tick (✓) two boxes.

The student wanted to prove that it was the yeast producing the gas.

Which suggestion would allow the student to prove this?

Tick (✓) one box.

Anaerobic respiration also happens in animal cells.

The reactant used is glucose / carbon dioxide / lactic acid.

The product is glucose / carbon dioxide / lactic acid.

Energy from cellular respiration can be used to transport molecules across cell membranes.

What is the name of this process?

Tick (✓) one box.

The heart and blood transport substances to and from cells in the human body.

The diagrams show two human cells.

Cell A has more mitochondria than cell B.

Cell A will need to take in more of some substances than cell B.

Which two substances will cell A need to take in more of?

carbon dioxide dissolved food molecules oxygen urea water

Explain why cell A needs more of these substances.

Blood travels in blood vessels.

Kareem looks at two blood vessels using a light microscope.

The diagrams show what he sees.

Kareem thinks vessel X is an artery and vessel Y is a vein.

Explain why he is correct.

What other structure not shown in the diagrams would be found in a vein?

Kareem uses a ×10 eyepiece lens and a ×40 objective lens to look at the slides using the microscope.

What is the total magnification of these two lenses?

Total magnification = ×........

A doctor finds a problem with Kareem’s heart.

A bypass operation would help Kareem’s heart to work normally again.

The doctor uses a diagram to show Kareem how the operation would help him.

Use the diagram to explain the cause of the problem and how the bypass operation would help him.

Kareem is at risk of having a heart attack.

If Kareem changes his lifestyle he could lower his risk of heart attack.

Explain why it may be better for Kareem to change his lifestyle rather than have a bypass operation.

Approximately one quarter of all the trees in Great Britain are ash trees.

In 2012 scientists found trees with a disease called ash dieback.

Ash dieback is a communicable disease.

bacterium fungus protist virus

How is ash dieback spread from one tree to another?

Tick (✓) two boxes.

Scientists have collected data on the spread of ash dieback since 2012.

The scientists divided Great Britain into squares.

Each year they recorded the number of squares in which ash dieback was identified for the first time. The results are shown in Table 6.1.

Complete the bar chart using the data in Table 6.1 and label the x-axis.

Which year does not fit the trend in the data?

2012 2013 2014 2015 2016

Table 6.2 shows data for the individual countries within Great Britain.

Calculate the percentage of all squares in Wales with ash dieback.

Give your answer to 1 decimal place.

Use the data in Table 6.2 and your own knowledge to explain why scientists are concerned about ash dieback arriving in Great Britain.

Amaya is planning an investigation.

She wants to find out how temperature affects the rate of photosynthesis.

The information below is taken from her lab notebook.

Amaya plans to investigate four different temperatures.

Room temperature is 20 °C.

Describe how Amaya can set up her experiment at the other temperatures.

Which factors should Amaya keep the same to make sure she collects valid data?

Tick (✓) two boxes.

Table 7.1 shows Amaya’s results.

What is the range for the results at 30 °C?

Calculate the mean number of bubbles at 30 °C.

Describe the pattern of results shown in Table 7.1 and use ideas about enzymes to explain the pattern of results.

Amaya repeats her investigation at a temperature of 50 °C.

She finds a lower mean number of bubbles.

Explain why.

A plant makes glucose when it photosynthesises. The glucose is then turned into starch for storage.

A student wants to show that there is both glucose and starch in a leaf from a plant.

Draw a line to link each substance to the reagent the student should use to test for it.

Jamal sees this picture of a male peacock and a female peahen in his textbook.

Peahens have plain grey feathers, which makes it hard for predators to see them.

The male peacock has brightly coloured feathers and a large tail that it uses to attract peahens so they can mate.

Suggest two disadvantages of the male peacock’s brightly coloured feathers.

* Jamal’s textbook says that the male’s bright feathers and large tail evolved by natural selection, even though there are some disadvantages to having them.

Explain how the male peacock’s features evolved by natural selection and why they are still present despite these disadvantages.

Read the newspaper headline.

Having only males born into a family for this length of time is very unusual.

Use your knowledge of how human sex is determined to explain why having only males is very unusual.

Use the Punnett square in your answer.

Gametes are made by cell division.

A fertilised egg divides to make body cells using a different type of cell division.

Complete the table describing the two types of cell division.

Scientists collected data on blood cholesterol levels and death from heart disease in men.

The graph in Fig. 10.1 shows the relationship between blood cholesterol and the death rate from heart disease in the United States, Japan and two areas of Europe.

Blood cholesterol levels are measured in millimoles per litre (mmol / l).

How many moles are there in a millimole?

0.001 0.01 0.1 10 100 1000

A student reads off the graph and concludes that the death rate for men with a blood cholesterol level of 5.20 mmol / l is 15 deaths from heart disease per 1000 men.

Is the student’s conclusion correct?

Use data from the graph in Fig. 10.1 to explain your answer.

A man in the United States has a blood cholesterol level of 6.50 mmol / l.

The graph in Fig. 10.1 shows that 15 out of every 1000 men with this blood cholesterol level will die from heart disease.

Calculate the probability that he will die from heart disease.

Give your answer to 1 significant figure.

In a sample of 1000 men from the United States, 20 died from heart disease.

Use the graph in Fig. 10.1 to estimate the mean blood cholesterol level of these men.

Blood cholesterol level =........ mmol /

The scientists could collect other information to help explain the data on the graph.

One example of other information they could collect is the ages of the men in the study.

Suggest other examples of information they could collect to help explain the data.