Edexcel GCSE Biology Paper 2 Higher June 2022 question paper 1BI0/2H

1 (a) Bloodworms in a pond indicate that the water is polluted.

(i) Which species also indicates that the water is polluted?

(ii) Bloodworms have a high level of haemoglobin in their blood. Give a reason why this helps them survive in polluted water.

(iii) Carbon dioxide diffuses from the body of the bloodworm into the water. Give two factors that affect the rate of diffusion.

(b) Figure 1 shows part of a diseased rose plant from a garden.

(Source: © Manfred Ruckszio/Shutterstock)

Figure 1

Explain what Figure 1 indicates about the air quality in the garden.

2 (a) Figure 2 shows xylem and phloem from the stem of a plant.

(i) Living cells in phloem use energy to transport sucrose. Which organelles release energy in living cells?

(ii) Describe two features of the structure of xylem vessels that can be seen in Figure 2.

(b) A scientist investigated how the flow of air affected the rate of transpiration in a plant. A fan was used to change the flow of air. The volume of water taken up by the plant was measured. Figure 3 shows the results of this investigation. fan switched on

time in minutes

Figure 3

(i) Explain why switching on the fan caused a change in the volume of water taken up by the plant.

(ii) Give one reason why the volume of water taken up by the plant was also measured when the fan was not switched on.

(iii) Calculate the rate of water uptake from 8 minutes to 10 minutes when the fan was switched on. Use the equation

_{..............................................................}mm³ per minute

3 (a) Figure 4 shows a cross-section of an artery and a vein.

(Source: © The University of Kansas Medical Center)

Figure 4

(i) Explain one difference between the artery wall and the vein wall shown in Figure 4.

(ii) Name one structure that is found in veins but not found in arteries.

(b) A human body has 5 dm³ of blood. At rest 20% of the blood travels to the muscles. During exercise 60% of the blood travels to the muscles.

(i) Calculate the volume of blood travelling to the muscles during exercise.

(ii) Explain one reason why there is an increase in blood flow to muscles during exercise.

4 A student investigated the width of leaves on nettle plants growing in two areas next to a woodland. Figure 5a shows a nettle plant and Figure 5b shows a map of the woodland showing area A and area B. The woodland caused area A to be in the shade.

(Source: © Alila Medical Media/Shutterstock) Figure 5a Figure 5b The student measured the maximum width of leaves on five plants from each area. The student always measured one leaf from the fourth pair of leaves.

(a) Give one reason why the student always measured a leaf from the fourth pair of leaves.

(b) Figure 6 shows the results.

(i) Why did the student not include the circled width when calculating the mean for area B?

(ii) Explain the difference in the mean width of leaves in the shade and those in the sunlight.

(c) The student also studied some of the animals in areas A and B. The student saw caterpillars eating the leaves of some nettles. The student also saw a toad eating a large beetle. Large beetles eat ladybirds. Ladybirds eat caterpillars.

(i) Give the food chain for these feeding relationships.

(ii) Frogs also eat large beetles. Figure 7 shows the energy transferred between these animals.

Calculate the percentage efficiency of energy transfer from the large beetles to the frog.

(iii) Give two reasons why only some of the energy in the biomass of the large beetles is transferred to the biomass of the frog.

5 (a) Figure 8 shows a cross-section of a root nodule on a leguminous plant. Bacteria in the root nodule provide the leguminous plant with nitrogen compounds. The leguminous plant provides the bacteria with sugars.

(Source: © Nigel Downer / Science Photo Library)

Figure 8

(i) Which term describes the relationship between this leguminous plant and the bacteria?

(ii) The width of this root nodule is 7.5 mm. Give the width in µ m.

(b) Figure 9 shows part of the nitrogen cycle.

(i) Identify the types of microorganism involved in process X and process Y.

(ii) Explain how crop rotation increases nitrate levels in the soil.

(iii) Explain why increased nitrate levels in the soil improve crop yield.

6 (a) The combined contraceptive pill contains artificial versions of oestrogen and progesterone.

(i) Explain how the combined contraceptive pill prevents pregnancy.

(ii) When taken correctly, the combined pill can be over 99% effective. Taking the combined pill can lead to weight gain. Give one other disadvantage of using the combined pill as the only method of contraception.

(b) Excessive weight gain and obesity increase the likelihood of developing type 2 diabetes. Explain the effect of type 2 diabetes on the body.

(c) A woman had unexplained weight loss and fatigue. She had blood tests to investigate the cause of these symptoms. Figure 10 shows the results.

Figure 10

Comment on the results of these blood tests and the possible causes of the woman’s weight loss and fatigue.

7 (a) A gardener read information on a gardening society website about how to use a compost bin. Figure 11 shows the compost bin and some of the instructions.

Figure 11

(i) Give one reason why the gardener thought the gardening society website was a good source of information.

(ii) Give reasons why soil is added to the compost bin and why the contents are turned to add air.

(iii) The gardener noticed the compost bin became warm a few days after vegetation was added. Why did the contents of the compost bin become warm?

(iv) The mass of the contents of the compost bin at the start was 40 kg. After 60 days the mass of the contents was 32 kg. Which is the rate of decay?

*(b) Explain the uses of auxins, gibberellins and ethene in the commercial production of plants and fruits.

8 The effect of different types of exercise on the heart rate of an athlete was investigated. The athlete counted the number of beats in 10 seconds at the carotid artery pulse point, as shown in Figure 12. This measurement was used to calculate the heart rate.

(Source: © dityazemli/Shutterstock)

Figure 12

The athlete exercised for 20 minutes. The heart rate was recorded every 5 minutes during each type of exercise.

(a) (i) State how the heart rate was calculated using this method.

(ii) Give two ways of improving the method used to obtain the data needed to calculate the heart rate.

Figure 13 shows the results of this investigation.

Figure 13

(iii) Comment on the difference in the heart rates during these types of exercise.

(b) Exercise increases adrenalin levels.

(i) State which endocrine gland secretes adrenalin.

(ii) Explain the effect of adrenalin on liver cells during exercise.

(c) After high intensity exercise, the pH of muscles can decrease from pH 7.0 to pH 6.3. Explain this change in pH.

9 (a) Scientists use a technique called mark and recapture to estimate animal populations in a habitat. A sample of the population is captured and a harmless mark is added to each animal. These animals are released and after a period of time the population is sampled again. This second sample includes some recaptured animals that have marks on them. The population can be estimated using this equation number marked in the first sample × size of the second sampl e number marked in the first sample size of the second sample population size = number recaptured in the second sample A scientist used this technique to determine the change in the population size of snails in a pond from March to July. Figure 14 shows the results.

Figure 14

(i) Using data from Figure 14, calculate the difference in the population size from March to July.

Difference in the population size_{..............................................................}

(ii) State two factors the scientist should control when sampling the habitat in March and July.

(b) This pond is affected by eutrophication. Explain one possible cause of eutrophication.

*(c) Reforestation has a beneficial effect on air composition and biodiversity. Animal conservation projects can also have a beneficial effect on biodiversity. Explain the beneficial effects of reforestation and animal conservation projects.

10 (a) When training, an athlete noticed some types of T‑shirts became wetter and heavier due to sweating. This athlete has three T‑shirts, each made of a different material. Devise a method this athlete could use to find the best T‑shirt for training.

(b) Athletes often eat a high protein diet.

(i) Which is the test and result for a food containing protein?

(ii) Digested protein is absorbed in the small intestine by diffusion. Figure 15 shows part of the small intestine.

(Source: © Science Photo Library C047/6177)

Figure 15

Using Figure 15 and Fick’s law, explain the effect of the villi on the rate of diffusion.

(iii) Digested protein enters the blood as amino acids. State which component of the blood transports amino acids.

(c) Explain how high levels of amino acids in the blood cause a high concentration of urea in urine.