Communities & competition

Students investigated how many daisy plants were growing in a field at different distances from a tree.

This is the method used.

1. Place a 20-metre tape measure on the ground, with the tree at 0 metres.

2. Place a 1 m² quadrat on the ground every 4 metres along the tape measure.

3. Count the number of daisy plants in each quadrat.

4. Take a soil sample from each quadrat to find the percentage of water in the soil.

Figure 2 shows the tree and the tape measure.

This is the method used for finding the percentage of water in each soil sample (step 4):

5. Weigh an empty container.

6. Place the soil sample in the container and weigh again.

7. Heat the container of soil in an oven at 100 °C for several hours.

8. Allow the container of soil to cool and weigh again.

9. Repeat steps 7 and 8 until there is no further change in mass.

Suggest why the students repeated steps 7 and 8 until there was no further change in mass.

Table 2 shows the results.

Calculate percentage X in Table 2.

Give your answer to the nearest whole number.

Describe the effect of distance from the tree on the percentage of water in the soil between 4 metres and 16 metres.

Use Table 2.

A student concluded:

‘As the water content of the soil increases, so does the number of daisy plants.’

Describe two changes to the investigation that would increase the validity of the student’s conclusion.

The percentage of water in the soil is an abiotic factor.

Suggest three other abiotic factors that might have caused more daisy plants to grow further away from the tree.

Do not refer to water in your answer.

Genetic engineering can be used for making many useful products.

Figure 3 shows how a vaccine against a virus can be made by genetic engineering.

Use information from Figure 3 to answer questions 03.1 and 03.2.

Which part of the virus is put into the yeast cell?

Which part of the virus is made by the yeast cell?

A long time ago, vaccines were made in a different way.

The virus was heated to stop it reproducing.

The vaccine contained whole viruses.

Why might the vaccine containing heat-treated viruses be dangerous?

Tick (✓) one box.

Genetic engineering can also be used in agriculture.

Weeds are a problem for farmers because the weeds compete with crop plants.

Give three factors that the weeds and crop plants compete for.

Glyphosate is a weed killer used in agriculture.

Genetically modified (GM) maize is a food crop that is resistant to glyphosate weed killer.

Farmers can spray glyphosate on a field to kill the weeds where the GM maize is growing.

Suggest one advantage of using glyphosate on fields where GM maize is growing.

Suggest one problem of using glyphosate on fields where GM maize is growing.

Do not refer to cost in your answer.

Many different species can live together in the same habitat.

What name is given to all of the organisms living in the same habitat?

Tick (✓) one box.

Figure 12 shows four species of bird from the same habitat in the UK.

Brambling (Fringilla montifringilla)
Bullfinch (Pyrrhula pyrrhula)

Chaffinch (Fringilla coelebs)
Goldfinch (Carduelis carduelis)

Which species of bird in Figure 12 do scientists think are most closely related?

Tick (✓) one box.

Scientists think the brambling and the bullfinch belong to different species.

What evidence is used by scientists to classify the brambling and the bullfinch as different species?

Tick (✓) one box.

Four other species of bird (A, B, C and D) live in a habitat in the UK.

Figure 13 shows how the numbers of each species of bird varied during one year.

Use information from Figure 13 to answer Questions 07.4 to 07.6

Describe what happens to the number of birds of species A during the year.

In June and July, a disease affected the populations of some of the species.

Which species had the lowest resistance to the disease?

Tick (✓) one box.

One species migrates between the UK and other countries.

Which species migrates between the UK and other countries?

Give a reason for your answer.

Many different species can live together in the same habitat.

What name is given to all of the organisms living in the same habitat? Tick (✓) one box.

Figure 1 shows four species of bird from the same habitat in the UK.

Brambling (Fringilla montifringilla) Bullfinch (Pyrrhula pyrrhula)

Chaffinch (Fringilla coelebs) Goldfinch (Carduelis carduelis)

Which species of bird in Figure 1 do scientists think are most closely related? Tick (✓) one box.

Scientists think the brambling and the bullfinch belong to different species. What evidence is used by scientists to classify the brambling and the bullfinch as different species? Tick (✓) one box.

Four other species of bird (A, B, C and D) live in a habitat in the UK. Figure 2 shows how the numbers of each species of bird varied during one year.

Use information from Figure 2 to answer Questions 01.4 to 01.6

Describe what happens to the number of birds of species A during the year.

In June and July, a disease affected the populations of some of the species. Which species had the lowest resistance to the disease? Tick (✓) one box.

One species migrates between the UK and other countries. Which species migrates between the UK and other countries? Give a reason for your answer.

The growth of daisy plants on a lawn is affected by biotic factors and by abiotic factors.

Table 2 shows six factors. Tick () one box in each row to show whether the factor is biotic or abiotic.

Figure 8 shows a plan of a garden.

A student estimates the number of daisy plants growing on the lawn. The student places a quadrat at 10 different positions on the lawn. The quadrat measures 50 cm 50 cm. The student counts the number of daisy plants in each quadrat.

How should the student decide where to place the quadrat? Give the reason for your answer.

The mean number of daisy plants in each quadrat is 6. Calculate the number of daisy plants on the lawn. Give your answer to 3 significant figures.

Number of daisy plants on the lawn =

Using the mean from this investigation to calculate the number of daisy plants on the lawn may not be accurate. Give two reasons why.

The Galapagos Islands are located in the Pacific Ocean. Several species of birds called finches live on the Galapagos Islands. These finches are very similar to each other. Figure 15 shows two modern species of Galapagos finch and their classification.

Figure 15

Medium ground finch Small ground finch

Complete Figure 15 to give the names of the missing classification groups.

Give the binomial name of the medium ground finch. Use information from Figure 15.

In each species of finch, there is a variation in beak depth.

Figure 16 shows how beak depth is measured.

Figure 17 shows the relationship between the beak depth of parent birds and the beak depth of their offspring.

Give evidence from Figure 17 that beak depth is an inherited characteristic.

Scientists suggested that more than one gene controls beak depth. Give evidence from Figure 17 to support the scientists’ suggestion.

Figure 18 is a map of the Galapagos Islands.

On Isabela Island, the medium ground finch and the small ground finch are found. On Daphne Island, only the medium ground finch is found. On Crossman Island, only the small ground finch is found. Figure 19 shows how the beak depth of each species varies on each island.

The medium ground finch and the small ground finch both feed on seeds.

The size of seeds eaten by each bird depends on the depth of the bird’s beak.

The range of beak depth of medium ground finches on Isabela Island is different from the range on Daphne Island. Explain what might have caused this difference.

Figure 19 shows:

• the two species of finch live on Isabela Island

• only one of the species lives on Daphne Island

• only one of the species lives on Crossman Island.

Suggest why both species of finch are able to live on Isabela Island.

A student investigated the effect of light intensity on the growth of seedlings.

Figure 2 shows the equipment.

Which two improvements should the student make to the investigation?

Tick (✓) two boxes.

What is the dependent variable in the investigation?

Tick (✓) one box.

In each dish the seedlings compete with each other.

Give two factors the seedlings compete for.

Figure 3 shows a seedling growing towards a lamp.

What happened to the growth of the seedling on side P compared with the growth on side Q ?

Tick (✓) one box.

Plant responses are called tropisms.

Which tropism causes the seedling to grow towards light?

Tick (✓) one box.

Which hormone causes the seedling to grow towards the light?

Tick (✓) one box.