Edexcel IGCSE Biology Biology Paper 1 January 2023 question paper 4BI1/1B

The diagram shows a flower from an apple tree, with some structures labelled.

This apple tree is able to self-pollinate. Which is the correct transfer of pollen during pollination?

Which structure does the pollen tube grow down?

Which structure develops into the seed?

The flower from an apple tree is insect‑pollinated.

Give three differences between the structure of this apple flower and the structure of a wind‑pollinated flower such as grass.

The seeds of many plants are surrounded by sweet‑tasting fruit.

Suggest how this enables the plants to spread their seeds.

The diagram shows a transverse section through a human heart.

Draw an X on the diagram to show the position of the septum.

State two differences between the composition of the blood in the coronary artery and the composition of the blood in the coronary vein.

Explain the differences between the left ventricle wall and the right ventricle wall.

The development of coronary heart disease is linked to a number of factors.

Explain how these factors can increase the risk of developing coronary heart disease.

The diagram shows the nu content of two ry milk products, oat milk

of which 7g is sugar of which 7g is sugar 2 g fibre
1 g fibre 2 g protein
1 g protein

A person is told by their doctor that they need to lose weight. Use the information from the milk contents and your own knowledge to discuss which milk would be the most suitable for this person.

Suggest why a person might drink a non‑dairy milk such as oat or almond milk rather than cow’s milk.

Describe how a student could test a milk sample for glucose.

Human breast milk contains special proteins that give immunity to the baby.

Explain how these proteins can help protect the baby from disease.

The peppered moth is found in many countries.

Two different forms of the peppered moth are a light‑coloured moth and a dark‑coloured moth.

The dark‑coloured moth was first observed in cities when pollution, from burning coal, stained tree trunks black.

Scientists trapped moths in a city location from 1992 to 1998.

The table shows the scientists’ results.

Calculate the difference between the percentage of moths that are dark‑coloured in 1992 and the percentage of moths that are dark‑coloured in 1998.

Plot a line graph to show the number of light‑coloured moths and the number of dark‑coloured moths from 1992 to 1998.

Use a ruler to join the points with straight lines.

In the 1990s, many cities introduced laws that prevented the burning of coal.

Comment on the changes in the number of light‑coloured moths and the number of dark‑coloured moths between 1992 and 1998.

The chromosomes in a human cell can be photographed and then arranged in pairs to show the karyotype.

White blood cells are often used to show the chromosomes in the karyotype.

The chromosomes in white blood cells are larger and easier to see when the white blood cells divide.

Diagram 1 shows a karyotype.

Explain why a red blood cell cannot be used to show a karyotype.

State the type of cell division that occurs in white blood cells.

The karyotype in diagram 1 is from a male.

State how this can be deduced from the diagram.

Diagram 2 shows a karyotype from a white blood cell of another person.

The karyotype is from a female, and the person has a condition called Turner syndrome.

This condition affects the development of the ovaries so they may not produce normal quantities of sex hormones.

Comment on the differences between the karyotypes shown in diagram 1 and diagram 2 and the effects Turner syndrome will have on the person.

Use information from the question and your own knowledge in your answer.

Suggest how the difference in the chromosomes of people with Turner syndrome may have been produced.

A student uses this method to investigate osmosis in potato tissue.

• cut three 5.0 cm long cylinders from a raw potato

• dry the cut surfaces using filter paper

• measure the mass of each cylinder using a balance

• place one cylinder in a test tube containing 10 cm³ of concentrated sucrose solution, one cylinder in a test tube containing 10 cm³ of distilled water and one cylinder in an empty test tube

• put a bung in each test tube and leave them for one hour

• remove the cylinders and dry them with filter paper

• measure the mass of each cylinder again

• measure their lengths using a ruler

Describe what is meant by the term osmosis.

State the independent variable in the student’s investigation.

Osmosis is affected by the surface area and volume of the cylinders, so the student keeps the original surface area and volume of each cylinder the same.

At the start of the experiment each cylinder had a radius of 0.25 cm and a length of 5.0 cm.

Calculate the surface area of each cylinder using this formula.

[ l = length of cylinder, r = radius of cylinder and π = 3.14]

Explain how surface area would affect the rate of osmosis.

State another variable the student should control in the investigation.

The table shows the student’s results for the mass of the cylinders.

Explain the changes in the mass of the potato cylinder in each test tube.

The student also measured the change in length of each potato cylinder.

Assuming the length has the same percentage change as the mass, calculate the final length of the cylinder in the concentrated sucrose solution.

This food web is from an ecosystem in Africa.

Which organism is a primary consumer?

Which of these has the least efficient energy transfer?

Which organism will be least affected by a reduction in the population of star grass?

Explain why only a small proportion of the energy contained within one trophic level is transferred to the next trophic level.

Describe how a scientist could compare the population size of star grass in two areas of the ecosystem.

Wild dogs hunt a variety of prey species. They usually eat the weak and sick animals.

Explain how this behaviour may benefit the species the dogs hunt.

Yeast can be used in food production.

Which group of organisms does yeast belong to?

Which substance is the cell wall of a yeast cell made of?

A teacher sets up an experiment to investigate the effect of temperature on the rate of respiration in yeast.

The diagram shows part of the apparatus the teacher uses.

Explain what additional apparatus the teacher will need to investigate the effect of temperature on the rate of respiration in this experiment.

State the purpose of the liquid paraffin on the surface of the glucose solution.

Give the name of a suitable chemical that could be used as indicator X to show that the yeast is respiring.

Diazine green changes colour from blue to pink as the oxygen levels in the yeast and glucose solution reduce.

Explain how this colour change gives information about the respiration in the yeast.

Explain why the rate of respiration in the yeast will change as the temperature is increased.

Plants need light for photosynthesis.

Give the balanced chemical symbol equation for photosynthesis.

The graph shows the effect of light intensity on the rate of photosynthesis in a water plant.

The rate of photosynthesis is measured by counting the number of bubbles of gas released per minute.

The light intensity is decreased by moving a lamp further away from the water plant.

The light intensity is calculated as

= 1÷ (distance in cm of lamp from plant)²

Using information from the graph, calculate the distance of the lamp from the plant when the rate of photosynthesis is 78 bubbles per minute.

Describe the relationship between the number of bubbles per minute and light intensity.

Explain the rate of photosynthesis between a light intensity of 0.4 arbitrary units and a light intensity of 0.8 arbitrary units.

The table gives some information about enzymes in the human digestive system.

Complete the table by giving the missing information.

Some scientists have investigated the effect of vinegar (a weak acid) on the digestion of starch.

Design an investigation to discover the effect of vinegar on the digestion of starch.

Include experimental details in your answer and write in full sentences.