Edexcel GCSE Combined Science Paper 2: Biology 2 Higher June 2024 question paper 1SC0/2BH

A centrifuge can be used to separate the different parts of human blood.

Figure 1 shows blood separated into different parts.

Name part X.

Which substance, needed for cellular respiration, is carried by red blood cells?

Name two types of white blood cell.

When a person donates blood, 470 cm³ of blood is removed from their body.

Red blood cells make up 44 % by volume of the blood.

Calculate the volume of red blood cells in 470 cm³ of donated blood.

Give your answer to the nearest whole number.

_........ cm³

Before donating blood, a person has a small blood sample taken to check that the blood is healthy.

State two precautions a doctor should take when collecting this sample.

Figure 2 shows a root hair cell from a plant.

Name the part labelled X.

State one way that the structure of the root hair cell increases the volume of substances it absorbs.

Explain why root hair cells do not contain chloroplasts.

from the Elodea cells in tap water.

Explain why placing the Elodea cells in the 10% salt solution causes the changes seen in Figure 3.

A scientist decided to study the variety of living organisms in a garden.

The scientist wanted to use a random sampling technique.

Devise a plan the scientist could use to randomly sample the number of plant species in the garden.

The scientist also measured abiotic factors in the garden.

The pH of the soil was measured using a pH meter.

Describe how three other abiotic factors could be measured in the garden.

Mistletoe is a parasite that grows on some trees.

Figure 4 shows a tree with mistletoe growing on it.

Describe the feeding relationship between the mistletoe and the tree.

Nitrate fertilisers are used in the garden.

Explain why nitrate fertilisers are used in gardens.

A student investigated the effect of glucose concentration on the rate of anaerobic respiration in yeast.

The student used five concentrations of glucose: 5 %, 10 %, 15 %, 20 % and 25 %.

A teaspoon of dried yeast was added to 20 cm³ of the 5 % glucose concentration in a measuring cylinder.

A drop of washing up liquid was added and the mixture was stirred.

A reaction occurred and bubbles collected as foam on the surface of the mixture.

The height of the foam was measured after five minutes.

This method was repeated for each concentration of glucose.

Describe how to set up a control for this investigation.

State how the scientist could improve this investigation to increase the rate of the reaction.

The results of this investigation are shown in Figure 5.

The student thought one of the results was anomalous.

Explain which of these results is anomalous.

Explain why the height of the foam was greatest for the 25 % glucose concentration.

Figure 6 shows a human heart.

Draw arrows on Figure 6 to show the direction of blood flow through the left side of the heart.

Name the main blood vessel that carries deoxygenated blood into the heart.

Figure 7 shows the heart rate and stroke volume of a person when at rest and when doing exercise.

Calculate the difference in cardiac output when at rest and when doing exercise.

Give your answer to 3 significant figures and include units in your answer.

_........

Explain why the cardiac output needs to increase during exercise.

The female contraceptive pill contains hormones to prevent pregnancy.

Which hormones are in the female combined contraceptive pill?

Explain how the hormones in contraceptive pills prevent ovulation.

Explain how a barrier method of contraception prevents pregnancy.

*(b) Hormones can be used as part of assisted reproductive technology.

Explain how assisted reproductive technology (ART) can be used to increase the chances of a woman becoming pregnant.