Edexcel IGCSE Biology Biology Paper 2 January 2020 question paper 4BI1/2BR

Suggest what is meant by the term sustainable (line 3).

Explain why having a developed root system makes regrowth quicker (lines 4 to 5).

Coppiced wood can be used as a biofuel (lines 8 to 9).

Give similarities and differences in the use of biofuel compared with the use of fossil fuels.

New growth in woodland is often destroyed by species such as deer (lines 5 to 6).

Suggest one way to protect woodland from this damage.

Coppicing increases biodiversity in woodland ecosystems (line 17).

Describe a method to investigate the effect of coppicing on the biodiversity of plants in a woodland.

Coppicing increases the number of insects in woodland.

A farmer owns a field next to a coppiced woodland.

Give one reason why more insects in the woodland might be an advantage for the farmer.

Give one reason why more insects in the woodland might be a disadvantage for the farmer.

Explain why a range of different light levels in a woodland leads to an increase in plant biodiversity (lines 23 to 24).

Insulin is a hormone produced in the human body.

Which organ produces insulin?

Describe the role of insulin.

Some humans cannot produce insulin and need injections of insulin every day.

This insulin can be obtained from cows, but this insulin might cause an immune response in the human body.

Why does cow insulin cause an immune response in humans?

The insulin now used for injections is obtained from bacteria that have been genetically modified.

Describe how these bacteria are genetically modified to produce human insulin.

An industrial fermenter is used to grow the genetically modified bacteria.

Explain why the fermenter is cleaned using steam before the genetically modified bacteria are added.

The diagram shows a northern white rhino.

The northern white rhino is in danger of becoming extinct.

In 2018, there was only one left in the world.

This represents a 99.95% decrease in numbers from 1960 to 2018.

Calculate the population size of the northern white rhino in 1960.

Cloning was considered as a method to increase the northern white rhino population.

In 2018, the only northern white rhino left was an old female. Old females produce too few eggs for cloning to be successful.

Suggest two reasons why many eggs are needed for cloning to be successful.

Scientists are considering using semen from a southern white rhino to fertilise an egg from the northern white rhino.

Fertilisation would take place in a test tube and produce a zygote.

Name the cell in semen that fertilises the egg.

Explain what the scientists should do with the zygote so that it develops into a fetus.

A student uses this apparatus to investigate the effect of windy conditions on transpiration.

This is the student’s method.

● measure water uptake for 30 minutes without a fan blowing air at the shoot

● measure water uptake for 30 minutes with a fan blowing air at the shoot

● measure the total surface area of the leaves

The student divides the water uptake by the total surface area of the leaves.

The table shows the student’s results.

Explain how the student sets up and uses this apparatus to measure the water loss.

Give two abiotic factors that the student should control in his investigation.

The total surface area of the plant leaves is 200 cm².

Calculate the time in minutes for the plant to take up 1.0 cm³ of water without a fan.

The student concludes that plants will grow better in windy conditions.

Evaluate this conclusion.

The molecules RNA and DNA are both involved in inheritance and protein synthesis.

Give two differences between the structure of a DNA molecule and the structure of an RNA molecule.

This sequence shows the order of bases on a DNA strand.

CATCATCCTCATCTA

Give the sequence of bases in the mRNA that would be produced from this strand.

The sequence of bases in the mRNA is used to code for the amino acids in a protein.

Calculate the number of bases required to code for an amino acid chain of 1400 amino acids.

A mutation results in a change in the sequence of bases in a DNA strand.

Discuss what effect a change in the sequence of bases could have on the functioning of the enzyme produced.

Give one way that the incidence of mutation could be increased.

The diagram shows some structures in the human abdomen.

Which structure is used to store urine?

Which structure produces adrenaline?

Identify two substances that would be carried in structure R.

Tube T is used for excretion and reproduction in males, but only for excretion in females.

Explain this difference in function.

The volume and concentration of urine produced varies depending on the water content of the body.

Explain how very warm weather results in a change in the concentration and volume of the urine.