Distribution of organisms (SQA National 5 Biology): Exam Questions

In an investigation into the distribution of woodlice in a woodland, students collected and counted them every day for five days using the sampling technique shown.

(i) Name this sampling technique.

[1]

(ii) Identify two variables that should be kept constant when setting up this sampling technique.

[2]

1. ....................................................................................

2. ....................................................................................

State one way in which the results could be made more reliable.

Which of the following is a biotic factor which could affect biodiversity?

The table shows the results of an investigation into the effect of temperature on egg laying mites.

As the temperature increases, the average number of eggs laid per female per day

Students investigated the distribution of some organisms on a rocky shore.

Starting at the lowest tide level, quadrats were placed every two metres along a single transect line and the number of barnacles and mussels were counted.

The results are shown in the table.

(i) Calculate the average number of mussels per quadrat.

[1]

................................ mussels

(ii) Describe how the reliability of the results could be improved.

[1]

Another group of students conducted a study of 10 rock pools found along the transect.

(i) To provide information about the levels of water pollution, samples of water were taken from these rock pools and examined for the presence or absence of certain species.

What name is given to these species?

[1]

(ii) Name the type of factors, such as pH, that can affect the distribution of organisms living in rock pools.

[1]

Which statement describes an abiotic factor?

Students surveyed an area of woodland and recorded the tree species growing there.

The table shows some features that can be used to identify the trees.

Use the information in the table to complete the key.

The students also investigated the effect of soil moisture on the number of Scots pine seedlings growing on the woodland floor.

(i) The students recorded the soil moisture and number of seedlings at 10 sample sites in the woodland.

Suggest why 10 sample sites were used.

[1]

(ii) The students used a moisture meter to measure the soil moisture.

Describe what the students should have done each time they used this apparatus to minimise error.

[1]

When investigating the distribution of bluebell plants in a woodland, five quadrats were thrown randomly.

Soil moisture and bluebell abundance values were recorded for each quadrat.

The results are shown in the table.

Predict the bluebell abundance if the soil moisture was 34%.

The following paired statement key can be used to identify some birds.

1. Has webbed feet .............................................go to 2
Does not have webbed feet.............................go to 3

2. Has a black head ..............................................puffin
Has a white head...............................................swan

3. Has a curved beak ...........................................go to 4
Has a straight beak ..........................................rook

4. Has a brown head............................................curlew
Has a black head .............................................avocet

Use the information in the key to identify two features of a curlew.

Light intensity readings were taken at 5 sites along a transect line running from an open field to a woodland.

Name the apparatus used to measure light intensity and give one precaution that should be taken when using it to minimise error.

Apparatus................................................................................................................

Precaution...............................................................................................................

Three readings were taken at each site at the same time on different days. The results are shown in the table.

(i) Suggest a reason why the readings taken on day 2 were lower than the readings on days 1 and 3.

[1]

(ii) Explain why three readings were taken at each site.

[1]

Light intensity is an example of an abiotic factor.

Name one other abiotic factor.