Origins of Biodiversity (DP IB Environmental Systems & Societies (ESS): SL)

Exam Questions

46 mins10 questions
1a1 mark

Ignoring the equator, state the name of the structures outlined with the thicker black lines in the figure below.

tectonic-plates
1b3 marks

As shown in the figure in part (a), the surface of the Earth is divided into crustal plates that have moved throughout geological time.

Complete the following sentences:

i)

Plates move apart at __________ plate margins.

[1]

ii)

Plates move together at __________ plate margins.

[1]

iii)

Plates collide at __________ plate margins.

[1]

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23 marks

List three causes of mass extinctions.

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31 mark

State the process being described below.

An area of forest contains a large single continuous population of lizards. A new river forms that divides this single population into two separate populations. This geographical barrier prevents the two smaller lizard populations from interbreeding, so no gene flow occurs between them.

isolation

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42 marks

Describe the concept of "fitness" and how it applies to the process of evolution via natural selection.

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1a2 marks

A group of biologists conducted an investigation on a remote archipelago (a collection of islands) in the Pacific Ocean. A species of mouse lives on these islands without any natural predators. The biologists measured the claw length of a large number of these mice.

On half of the islands, a species of snake was accidentally introduced that preys on the mice but that cannot climb trees. Several years after the snakes were introduced the biologists returned and found that on the islands with snakes, the claw length of the mice had changed. Some had shorter claws, enabling them to run faster, while others had longer claws, enabling them to climb trees.

Suggest the benefit to the scientists’ investigation of there being islands without any snakes present.

1b3 marks

When the biologists conducted the investigation in part (a), flooding of the islands was very rare. Now, due to climate change, flooding of the islands occurs more regularly. This flooding can regularly wipe out large numbers of ground-living species.

Using this information and the information from part (a), explain how the claw length of the mice on the islands are likely to be changing now.

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2a2 marks

The Pyrenean desman (Galemys pyrenaicus) is a small, semi-aquatic, globally threatened mammal related to moles and shrews. It lives in the Pyrenees, a mountain range between France and Spain, and can be seen in the image below.

 

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Outline two adaptive features of the Pyrenean desman.

2b3 marks

During a study that lasted many years, scientists found that the number of desman travelling from the northern population to the southern side of the mountain range was extremely low. The scientists suspect that the original desman species may have split into two different species.

Explain how the original desman species may have split into two separate species.

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33 marks

Describe the overall changes in global rates of extinction over time.

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4a3 marks

The apple maggot fly (Rhagoletis pomonella) is a species of fruit fly that lay their eggs on apples. As a result of this, they are often found in apple orchards where they can cause much damage to apple yields. Scientists studied two populations of apple maggot flies from orchards that were separated by a busy highway. They found that flies from the two populations had difficulty breeding successfully when kept in close confinement.

Suggest a reason for this observation.

4b6 marks

Even though nylon wasn't invented until the 1940s, bacteria were soon discovered that could degrade nylon. The bacterium, Paenarthrobacter ureafaciens, has special enzymes that allow it to metabolise nylon and use it as an energy source. This is a very simple example of natural selection.

i)

Describe how organisms can evolve through the process of natural selection.

[4]

ii)

The presence of an antibiotic can act as a selection pressure on bacterial populations.

Explain what selection pressure means in this context.

[2]

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17 marks

Explain the theory of plate tectonics.

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27 marks

Explain how plate activity has influenced the diversity of ecosystems.

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