Edexcel GCSE Biology Paper 2 Higher November 2021 question paper 1BI0/2H

The population of native white‑clawed crayfish in English rivers is decreasing due to an increasing population of American imported signal crayfish.

Figure 1 shows a white‑clawed crayfish.

Which term is used to describe the American imported signal crayfish now that it is living in English rivers?

American imported signal crayfish may eat white‑clawed crayfish.

Explain one other reason why the increasing population of American imported signal crayfish may have caused the decrease in white‑clawed crayfish.

The Environment Agency is developing methods of increasing the population of white‑clawed crayfish in English rivers.

Which term describes these methods?

White‑clawed crayfish cannot survive in rivers with a low concentration of oxygen.

Explain how eutrophication can cause the population of white‑clawed crayfish to decrease.

Figure 2 shows an area of woodland with some small plants growing in the ground between the trees.

(Source: © Maksym Holovinov/Shutterstock)

Figure 2

Name a group of organisms that break down the dead leaves and release mineral ions into the soil.

The mineral ions are absorbed from the soil into the roots of plants.

Describe how these mineral ions are transported from the roots to the leaves of the plants.

A scientist recorded the mean light intensity and the mean number of small plants per m² for six 25 m² areas of the woodland.

Figure 3 shows the results.

Explain the effect of light intensity on the number of small plants per m².

State one variable the scientist should have controlled to make sure the light intensity measurements could be compared.

The scientist selects an area near the edge of the woodland where many stinging nettles are growing.

This area is partly shaded by the trees.

Describe how the scientist should use a belt transect to investigate how light intensity affects the growth of stinging nettles.

Figure 4 shows ciliated epithelial cells from the airways of a human as seen using a light microscope.

Draw the cell labelled A in the box below.

Label three parts of this cell on your diagram.

State the function of the ciliated epithelial cells in the airways of the human breathing system.

Figure 5 shows equipment used to investigate the rate of respiration in maggots.

As the maggots respire, the drop of coloured liquid moves towards the test tube.

Figure 6 shows the position of the drop of coloured liquid after ten minutes.

Use information from Figures 5 and 6 to calculate the mean rate of respiration of the maggots in mm per minute.

Describe a control for this investigation.

Figure 7 shows the human urinary system.

Urine is made by removing water, urea and salts from the blood.

Use the letter X to label where urine is made.

Which substance is converted to urea in the liver?

A patient cannot remove enough urea from the blood when making urine.

Figure 8 shows a dialysis machine attached to the arm of this patient.

Their blood is pumped out of their arm, passed through the dialysis machine, and then put back into the patient.

Describe what happens to urea as the blood passes through the dialysis machine.

Two patients need to have dialysis treatment.

Patient A needs this treatment three times a week.

Patient B needs this treatment once a week.

Give one reason why patient B needs dialysis treatment less often than patient A.

Describe how to test for glucose in the dialysis fluid.

Urease is an enzyme that breaks down urea into smaller molecules.

Explain why urease will not break down starch into smaller molecules.

Figure 9 shows the structure and actual size of red blood cells (erythrocytes).

red blood cells side view of red blood cell (cut)

(Source: © N.Vinoth Narasingam/Shutterstock)

Figure 9

Calculate the image size of the top view of this red blood cell if this cell is

Give your answer in mm.

Explain how the shape of a red blood cell is related to its function.

State the role of haemoglobin inside the red blood cell.

Some blood transfusions contain red blood cells.

Red blood cells are stored in a solution containing 5.0% glucose and 0.9% salt.

Explain why red blood cells cannot be stored in pure water.

Methods of contraception include use of hormones and barrier methods.

Which form of contraception is a barrier method?

State why a barrier method of contraception may be used in addition to a hormonal method.

The combined contraceptive pill contains the hormones oestrogen and progesterone.

State the endocrine gland that releases oestrogen.

Explain how high levels of oestrogen and progesterone in the combined contraceptive pill work together to prevent pregnancy.

Hormones can also be used to treat infertility.

Explain how clomifene therapy and IVF can improve female fertility.

clomifene therapy_........

A hospital patient was tested for diabetes.

A nurse recorded his mass and height.

Figure 10 shows these measurements.

Calculate the BMI of this patient using the information in Figure 10.

Blood samples were taken from this patient every four hours.

The glucose concentrations were recorded in Figure 11.

Describe the trends shown in this data.

This patient was diagnosed as being type 2 diabetic.

Explain why the blood glucose concentration of this patient remained high from 4 hours to 8 hours.

This patient did some exercise during these 24 hours.

Explain how the data in Figure 11 shows that this exercise occurred after 8 hours but before 12 hours.

A student investigated the decomposition of leaves from different types of tree.

Decomposers in the soil convert

The student collected and weighed some fresh leaves from a beech tree.

• The leaves were placed on top of soil in a tray.

• This was repeated for leaves from three other types of tree.

• The trays were kept in the same abiotic conditions for 40 days.

• The leaves were reweighed after 40 days.

State two abiotic factors that should be kept the same in this investigation.

Explain how this investigation could be improved to make the results more comparable.

Figure 12 shows the mean rate of decomposition for this investigation.

Which leaves would produce compost in the least time?

The same investigation was extended to include the leaves of a silver birch tree.

The starting mass of the leaves was 28.2 grams.

After 40 days the mass of the leaves was 19.7 grams.

Calculate the rate of decomposition of the leaves of the silver birch tree.

Give your answer to three significant figures and include the units.

rate of decomposition_........

Explain how the concentration of oxygen in a compost bin would affect the rate of decomposition.

Exercise causes changes in the circulation of the blood.

In an investigation, the change in blood flow to different parts of the body during exercise was measured.

All the volunteers used in the study were healthy females of the same age.

Figure 13 shows the results of this investigation.

During exercise, the blood flow to the stomach changes.

Calculate the percentage change in blood flow to the stomach in response to exercise.

Give your answer to the nearest whole number

Suggest two other variables that should be controlled in this investigation.

*(iii) Explain the changes in blood flow, shown in Figure 13, that are caused by exercise.

Commercial growers can use plant hormones to artificially ripen fruit and produce seedless fruit.

Which is the name of the plant hormone used in fruit ripening?

Which plant hormone can commercial growers spray fruit with to produce seedless fruit?

The effect of applying weed killer containing plant hormones to fields of wheat was investigated.

In field A, the weed killer was applied each year for five years.

In field B, no weed killer was applied for the five years.

Each field was 1000 m² and all other conditions remained the same.

The results are shown in Figure 14.

Comment on the effect of using weed killer containing plant hormones in this investigation.

*(c) Figure 15 shows a pot plant before it fell over and the same pot plant two weeks after it fell over.

pot plant before pot plant two weeks after

Explain how hormones in the roots and shoots of plants caused this directional growth.