Edexcel IGCSE Biology Biology Paper 1 January 2017 question paper 4BI0/1B

The diagram shows a food web from a forest.

Use information from the food web to complete the table. The first one has been done for you.

Plant cell walls are made of cellulose. Cellulose is an insoluble molecule made from the same simple sugar as starch. The rabbit’s intestine contains bacteria that can digest cellulose. Suggest why this is an advantage for the rabbit.

The deer runs away when it sees the wolf.

Name the effector in this response.

The deer releases a hormone when it sees the wolf. Explain how this hormone helps the deer to run away.

The owl uses its eyes to find prey. The diagram shows a section through the owl’s eye.

Name the parts labelled A and B.

Describe the function of part A.

Describe the function of part B.

The photograph shows a chicken with feathers.

Scientists can use selective breeding to produce chickens with no feathers. Explain how a chicken with no feathers can be produced by selective breeding.

Selective breeding is also used to breed chickens for egg production and chickens for meat production. The graph shows how age affects the average (mean) number of eggs produced per chicken per year. The graph shows this information for chickens bred for egg production and for chickens bred for meat production.

Describe how age affects the number of eggs produced by each group of chickens.

Chickens in factory farms are kept in cages inside buildings rather than being kept outdoors. Suggest how factory farming can affect egg production.

Chemotherapy is often used to help people with cancer. Chemotherapy kills cancer cells but may affect haemoglobin production in the body. A drug called EPO increases haemoglobin production in the body. Scientists investigated the effect of EPO on patients who had received chemotherapy. They injected EPO into these patients and blood samples were taken for several months to measure their haemoglobin levels. The table shows the results.

Plot a line graph to show the relationship between time and average haemoglobin level. Use a ruler to join the points with straight lines.

Name the dependent variable in this investigation.

Explain how the scientists made sure their results were reliable.

The scientists controlled biotic (living) factors so their results would be valid. Name two biotic factors that the scientists should have controlled.

Cancer patients often complain of tiredness after chemotherapy. Explain how EPO helps to reduce tiredness in these patients.

The scientists obtained blood samples using a needle attached to a syringe. Explain which type of blood vessel they should use to obtain the blood samples.

4 (a) Nile tilapia are fish. Their body colour is controlled by a single gene. The allele N produces normal body colour and the allele n produces pink body colour. Diagram 1 shows the phenotypes and the genotypes of Nile tilapia. normal body colour (NN) normal body colour (Nn) pink body colour (nn)

Diagram 2 shows all the possible crosses between the phenotypes and genotypes of Nile tilapia parents.

The table gives some descriptions of offspring. Complete the table by giving the number of crosses that would produce each description of offspring. The first one has been done for you.

Tilapia are farmed in many parts of the world to provide a source of protein. Farmers build large ponds and fill them with fish. The ponds are exposed to sunlight and the farmers add manure to help the growth of the fish. Some of the water in the ponds is changed every day.

Suggest how sunlight and manure help the growth of the fish.

Suggest why some of the water is changed every day.

A fish farm contains 6000 fish. The average (mean) increase in mass of a fish over a period of 32 weeks is 700 g. Estimate the total mass of fish, in kg, that the fish farm could produce after 32 weeks.

This question is about the effect of salt on plant growth.

Explain what happens to a plant cell if it is put into a concentrated salt solution.

In the UK, salt is spread over road surfaces in winter to prevent ice from forming. When it rains this salt is washed on to the soil by the side of the road. Design an investigation to find out if plant growth is affected by the increased salt concentration in the soil. Your answer should include experimental details and be written in full sentences.

Plants make food by the process of photosynthesis.

Write a balanced chemical symbol equation for photosynthesis.

The leaf of a plant is adapted to carry out photosynthesis. Explain how the following parts of the leaf are adapted for photosynthesis.

palisade mesophyll layer

spongy mesophyll layer

guard cells

A student uses this method to show that starch is produced during photosynthesis. Step 1 put a potted plant in a dark cupboard for 24 hours Step 2 then put the plant in bright sunlight for 12 hours Step 3 remove a leaf from the plant and put it in a beaker of boiling water for 30 seconds Step 4 put the leaf in a boiling tube containing hot ethanol for 10 minutes Step 5 wash the leaf in cold water and put it on a white tile Step 6 add enough iodine solution to cover the leaf and observe the change in colour

Explain why the student put the plant in a dark cupboard for 24 hours in step 1.

Describe how the student could carry out step 4 safely.

State the colour of the leaf observed in step 6.

The student concludes that starch is produced by photosynthesis in the leaf. State a suitable control that she should use to make her conclusion valid.

Plants need to absorb mineral ions from the soil to enable them to produce other biological molecules. Complete the table by giving the missing information.

7 (a) A person touches a sharp pin.

Name the parts labelled A, B, C and D.

Explain how this reflex arc protects the body.

Reflexes in animals and phototropism in plants are both responses to stimuli.

Give two similarities between the mechanisms involved in each response.

Give two differences between the mechanisms involved in each response.

The diagram shows the carbon cycle with processes labelled A, B, C, D and E.

Name the process labelled A.

Give the letters of the processes that add carbon dioxide to the atmosphere.

Many people are concerned that too much carbon dioxide is being released into the atmosphere.

Suggest two actions that could be taken to reduce the amount of carbon dioxide being released into the atmosphere.

Describe the consequences of an increase in carbon dioxide for the world’s ecosystems.

A student carries out an experiment to investigate the effect of different concentrations of a food dye on diffusion.

Describe what is meant by the term diffusion.

The student adds a different concentration of coloured food dye to each of five wells in an agar plate. The diagram shows the agar plate at the beginning of the experiment and after 24 hours.

The student does the experiment using three plates. For each plate he measures the diameter of each circle to see how far the food dye has diffused. The table shows his results.

Calculate the average diameter for 0.2% concentration of food dye.

average diameter =_........

Describe the effect of food dye concentration on diffusion.

Explain the relationship between food dye concentration and diffusion.

State two variables that the student should control in this experiment to ensure that the results are valid.

The passage describes human reproduction. Complete the passage by writing a suitable word or words in each blank space.

During sexual intercourse the male’s_........ is inserted into the vagina. The male gametes, known as_........ , are released from the male urethra into the vagina. The male gametes carry on swimming until one meets a female gamete, known as the_........ . This process is fertilisation and takes place in a tube called the_........ .

The fertilised female gamete, also known as the_........ , moves down this tube. It undergoes the type of cell division called_........ and is now known as an_........ . This structure may then become implanted in the wall of the_........ .

The number of chromosomes in the fertilised female gamete is _........ the number found in the unfertilised gamete and is known as the_........ number.

The fungus Fusarium venenatum is grown in a fermenter to make a food product called mycoprotein.

Name the molecule that a fungus uses to store carbohydrate.

Name the thread-like structures that make up the mycelium of a fungus.

Mycoprotein contains low levels of fats and is high in protein. Suggest the benefits of each of these to a human diet.

Food production can be increased by using genetically modified plants that are resistant to disease. Explain how enzymes can be used to genetically modify plants.