Edexcel GCSE Combined Science Paper 1: Biology 1 Higher June 2018 question paper 1SC0/1BH

Obesity increases the risk of a person developing cardiovascular disease.

Losing weight can reduce the risk of this disease occurring.

Explain why exercise can cause weight loss.

Figure 1 shows a gastric band fitted to a stomach.

Explain how a gastric band helps a person to lose weight.

BMI and waist: hip ratio can be used to find out if a person is obese.

Figure 2 shows some data for two males.

BMI is calculated using the equation:

Male B has a mass of 72 kg and a height of 1.81 m.

Calculate the BMI of male B.

Give the answer to 3 significant figures.

BMI =_........

Figure 3 shows the interpretation of BMI values.

Males with a waist: hip ratio above 0.90 are defined as abdominally obese.

Explain what the BMI and waist: hip ratio for male A shows about his weight distribution.

(a) Figure 4 shows two potato chips.

Figure 5 shows some information about each potato chip.

Calculate the total surface area of potato chip B using the formula,

Total surface area = 2XY + 2XZ + 2YZ

total surface area =_........ cm²

The potato chips were placed in distilled water for 20 minutes.

Figure 6 shows the increase in mass of each potato chip.

Explain why potato chip B has a greater increase in mass than potato chip A.

Potato chip A is transferred from the distilled water into a concentrated salt solution.

Explain what will happen to the cells in potato chip A.

The potatoes of a potato plant develop underground.

Explain one difference in the sub-cellular structures in a cell in the potato and those in a cell in the leaf of the potato plant.

Streptococcus bacteria can cause a sore throat or skin infection.

An illness called scarlet fever can also develop during an infection with this bacterium.

Give two precautions a doctor should take when treating a patient who is infected with Streptococcus.

From September 2013 to March 2014 there were 2 830 cases of scarlet fever in the UK.

From September 2014 to March 2015 there were 5 943 cases of scarlet fever.

Calculate the percentage increase of the number of cases of scarlet fever between the periods September 2014 to March 2015 and September 2013 to March 2014.

_........ %

Figure 7 shows some Streptococcus bacteria.

Some bacteria are motile, meaning they can move themselves.

Why is a Streptococcus bacterium not motile?

Most cases of scarlet fever occur in children.

Adults have usually developed immunity to a toxin that the Streptococcus bacteria produce during infection.

Explain how an adult develops immunity to the toxin.

In 2012, two scientists were awarded the Nobel prize for their research on stem cells.

They showed that adult cells could be reprogrammed to become cells with the properties of embryonic stem cells.

Describe the possible benefits of this research.

Figure 8 shows four stages of mitosis, labelled P, Q, R and S.

Which is the correct order for these stages?

The stage of mitosis labelled S in figure 8 is

Interphase is part of the cell cycle.

Describe what happens during interphase.

Figure 9 shows a root tip with cells in different stages of mitosis.

The image was magnified 400 ×.

Explain how a magnification of 400 × can be obtained using the lenses on a light microscope.

Potato cells contain the enzyme catalase.

This enzyme catalyses the breakdown of hydrogen peroxide into oxygen and water.

Figure 10 shows what happened when a student placed a potato disc in a 5% hydrogen peroxide solution.

The student measured the time taken for the potato disc to rise.

The student repeated the investigation using 10%, 15% and 20% concentrations of hydrogen peroxide solution.

Which term describes the hydrogen peroxide in this reaction?

The potato discs all had the same mass.

Explain why the student used potato discs with the same mass.

State two other factors that need to be kept the same to improve this investigation.

Figure 11 shows the results of this investigation.

The student calculated the rate of reaction using

State and explain a conclusion based on these results.

The student repeated the investigation with a 25% hydrogen peroxide solution and recorded a time of 75 seconds.

Calculate the rate of reaction for the 25% hydrogen peroxide solution.

_........ s⁻¹

The student decided that the rate for the 25% hydrogen peroxide solution was not anomalous.

Give the reason why the result was not anomalous.

(a) Yeast cells can be genetically modified to produce a painkiller.

This painkiller is usually obtained from opium poppies.

One method for genetically modifying a yeast cell uses a plasmid containing the desired gene.

Explain how a gene can be inserted into a plasmid.

Discuss the possible benefits and risks of producing painkillers from genetically modified yeast cells rather than extracting the painkillers from poppies.

Figure 12 shows the structure of a DNA nucleotide.

Structure A is a

*(ii) In 2003, the first complete human genome was sequenced.

The genomes of different people have small changes in the sequence of the DNA bases.

Describe how these changes in DNA sequence can affect the individuals and how sequencing a person’s genome could influence their medical treatments.