Classification & Biodiversity (WJEC GCSE Biology): Exam Questions

The five Kingdom system can be used to classify all living things. Complete the classification chart, Image 4.1, by inserting the names of the two missing Kingdoms.

Image 4.1

In 1825, red pandas were classified as members of the racoon family (Procyonidae). Later, they were classified as members of the bear family (Ursidae). The most recent research has classified red pandas in their own family (Ailuridae). Image 4.2 shows red pandas. Image 4.2

Image 4.2

Suggest the evidence that would have been used in 1825 to classify red pandas.
State the type of evidence available to researchers more recently that resulted in the reclassification of red pandas.

In 2015, the International Union for Conservation of Nature (IUCN) assessed red pandas as endangered.

Table 4.3 shows the results of studies into population densities of red pandas in five districts of Nepal between 1989 and 2014.

Table 4.3

(i) Calculate the population density of red pandas in the Rara district in 2014.
Write your answer in Table 4.3.

[1]

(ii) In 1991, the population density of red pandas in Langtang had decreased to 0.17 per km² .
Suggest one reason for the decrease.
State one method by which endangered species could be conserved.

[2]

Reason for decrease
.....................................................................

Method of conservation
.....................................................................

(iii) Using data from Table 4.3, suggest the district in which red pandas have the highest chance of survival. Give a reason for your answer.

[1]

In the 1980s young terrapins (Trachemys scripta) from North America were sold in pet shops throughout the UK. When the terrapins became adults, many people no longer wanted them and released them into local ponds. The animals can live for up to 50 years.

Table 4.1

After release, adult terrapins eat native animals including invertebrates and vertebrates such as frogs and fish. In some ponds, native species have been reduced or lost completely.
Since 1992 a law has banned the import of terrapins into the UK.

Use the information to answer the questions.

Complete the classification of the terrapin.

Kingdom ..............................
Phylum Chordates (Vertebrates)
Class Reptiles
Genus .......................................
Species ...................................

(i) Calculate the increase in body length per year for an adult terrapin in the ten years between 2 years old and 12 years old.

[2]
Increase in body length = ..............................mm/year

(ii) Suggest one reason why some people did not want to keep the terrapins when they became too big.

[1]

Complete Table 4.2 by writing true or false for each of the statements. One row has been done for you.

Table 4.2

In the USA, these terrapins are called red-eared sliders and in Welsh they are called terapin clustgoch.

State how scientists from different countries ensure that they are all talking about the same species.

Barnacles are small animals that grow on rocks at the seashore.
Two species of barnacle native to the British Isles, Chthamalus stellatus and Semibalanus ,balanoides are shown in the photographs in Image 7.1.

Image 7.1

Students carried out a survey to test the following hypothesis:

C. stellatus is found further up the seashore towards the high water mark.
S. balanoides is found lower down the seashore towards the low water mark.

Image 7.2

The students measured the abundance and distribution of barnacles between the high water mark and the low water mark on the seashore. The results of their survey are shown in Table 7.3.

Table 7.3

Describe the method the students would have used to measure the abundance and distribution of barnacles between the high and low water mark.

(i) State two environmental factors which could affect the population of barnacles.

[2]

I. .............................................
II. ............................................

(ii) Calculate the ratio of C. stellatus to S. balanoides at the 25m mark.

[1]

C. stellatus .......................... : S. balanoides ......................................

(iii) State the type of competition occurring between the two species of barnacles at the 25m mark.

[1]

(iv) State whether the results of the survey support the students’ hypothesis (given on page 15). Use the data provided in Table 7.3 to give a reason for your answer.

[1]

Images 2.1A and 2.1B show the hazel dormouse (Muscardinus avellanarius) in winter and summer.

• Dormice are nocturnal (active only at night).

• In summer, they live high up in trees and bushes, eating berries and insects.

• In winter, they hibernate (being completely inactive) and keep warm in nests at ground level.

• Between the years 2000 and 2020 the dormouse population in the UK decreased and it became an endangered species in some areas.

• In 2000, as part of a local action plan, 1000 dormice were released into an area and their numbers later increased to 1050.

Use the information to answer the following questions.

State one way in which the dormouse body structure is adapted to:

[3]

(i) survive in low temperatures;

(ii) climb in branches of trees;

(iii) look for food at night.

State one way in which the behaviour of the dormouse helps it to survive in its environment.

Using the information, complete the table by writing true or false for each statement.

Limpets (Patella vulgata) are animals without backbones which live on rocky seashores, feeding on plants.

State the scientific term for animals which do not have backbones.

Students investigated the density of limpets (number per m² ) on two rocky shores in Anglesey. One shore was sheltered and one was exposed to heavy wave action.

Students’ method:

• Select a section on each shore of 300m² .

• Place quadrats, each of area 1m² , at 10 random co-ordinates in each of the two shore sections and collect data.

• Compare the data for the two shores.

(i) Table 6.1 shows one part of the students’ risk assessment for the investigation.

Complete Table 6.1.

[1]

Table 6.1

(ii) Describe in detail the techniques the students should use to place their quadrats at random and collect data.

[3]

The results of the investigation are shown in Tables 6.2 and 6.3

Table 6.2

Number of limpets on exposed shore:

Table 6.3

Number of limpets on sheltered shore:

(iii) Complete Table 6.3 for the sheltered shore by calculating:

[3]

I. The mean number of limpets per m² .

II. The estimated total number of limpets in the 300m² section of the shore.

(iv) I. From these results, state what the students could conclude about the density of limpets when they compared the two shores.

[1]

II. Suggest an explanation for this observation.

[1]

(v) State which of the quadrats (1–10) from the exposed shore shown in Table 6.2 had an anomalous result and describe what should have been done to take account of this.

[2]

Biological control is used to reduce the numbers of a pest population through the introduction of another species. It has been used with varying success since the 19th century.

(i) State two advantages of this method of control.

[2]

Advantage 1.....................................................

Advantage 2....................................................

(ii) State two disadvantages of this method of control.

[2]

Disadvantage 1...............................................

Disadvantage 2..............................................

The whitefly (Trialeurodes vaporariorum) is a pest which damages greenhouse crops such as tomatoes. Whitefly numbers can be reduced by using the biological control agent Encarsia formosa.

Graph 7.1 shows the number of whiteflies in a greenhouse containing tomato plants. E. formosa were introduced on day 7.

Graph 7.1

(i) I. The use of E. formosa to reduce the number of whiteflies is considered to be successful when there are 20 or fewer whiteflies per plant. Use Graph 7.1 to determine how many days it took for the number of whiteflies to fall to 20 following the introduction of E. formosa.

[2]

.................................................. days

II. Suggest a reason why it took this long for the number to fall to 20.

[1]

(ii) Suggest one reason why this method of pest control would not be effective to use if whiteflies damaged wheat crops grown in Wales.

[1]

(iii) An alternative approach to reducing pest numbers is to use pesticide. State why it is not appropriate to use pesticide along with E. formosa.

[1]

The yellow crazy ant (Anoplolepis gracilipes) was introduced accidentally to northern Australia. Due to the ecological damage it has caused, it is on a list of “one hundred of the world’s worst invasive species” produced by the International Union for Conservation of Nature (IUCN). The ants build super-colonies that disrupt native habitats.

(i) State what is meant by the term invasive species.

[1]

(ii) State the genus of the yellow crazy ant.

[1]

(iii) Explain how the formation of super-colonies affects biodiversity.

[1]