Year 9 – Science – Natural Selection and Genetic Modification – 3

Year 9 Topic 3: Natural Selection and Genetic Modification

Learning Opportunity 3: Darwin’s Theory

This learning opportunity has 5 tasks.

Target time: 60 minutes

By the end of this learning opportunity you will be able to:

Recall the 5 main stages of Darwin’s theory.

Explain Darwin’s theory of evolution by nature selection.

Apply knowledge of natural selection to explain how any species has evolved over time.

Use keywords: variation, survival of the fittest, offspring. 

Key words: Variation, environmental, inheritance, evolution, survival of the fittest.

Task 1:

Can you name 3 animals which have quite unusual adaptations and variation? E.g. a hedgehog with its spines. 

Why do these 3 animals have these adaptations? E.g. a hedgehog’s spines protect it from predators.

Task 2: Watch the video and then answer the questions below.

  1. Where did Darwin carry out his research? 

2. What was his published book called? 

3. What are the three important concepts? 

Answers are available at the end of this learning opportunity.

Task 3: Match up the following ideas of Darwin’s theory. Watch the video again if you need to.

Answers are available at the end of this learning opportunity.

Task 4: Use the stages above to explain why elephants have evolved to have trunks. Use the template to create a flow diagram. You need to consider why their trunks are useful before starting the task. There is an example below the flow diagram for the evolution of giraffes necks.

Giraffe neck example:

Task 2 Answers
  1. The Galapagos Islands.

2. On The Origin Of Species.

3. Natural selection, evolution and the origin of species.

Task 3 Answers

Task 5: Complete these exam questions.

Q1.  Charles Darwin studied the variety of finches on the Galapagos Islands.  He used this information to develop his theory of evolution. Some of the finches are shown in the diagram. 

(a)   (i) Suggest how the size and shape of their beaks enabled all of these types of finches to survive.

  …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………..  (2)

(ii) Complete the sentence by putting a cross next to your answer. 

  Darwin’s finches are an example of speciation due to

  A   selective breeding 

  B   geographic isolation 

 C   hybridisation 

 D   the development of ring species 

(1) 

(b) Suggest how these species of finches could have evolved. 

      ……………………………………………………………………………………………………………………………. 

      ……………………………………………………………………………………………………………………………. 

      ……………………………………………………………………………………………………………………………. 

      ……………………………………………………………………………………………………………………………. 

      ……………………………………………………………………………………………………………………………. 

      ……………………………………………………………………………………………………………………………. (3) 

(Total for Question is 8 marks) 

Mark scheme – Mark your answers

Q1. 
 

   Answer  Acceptable answers  Mark  
a(i)  A suggestion including two of the following:  
·(different beak sizes/adapted) enable different finches to feed on different food types (1)  
·less competition between species (1)   
  eat different foods accept comparison between 2 beaks and food source      more species are able to co-exist (1)       (2)  
a(ii)  B    geographic isolation       (1)  
b A suggestion linking three of the following points:  
·variation between species/ beak sizes/ shapes (1)  
·due to mutation(1)  
·competition for resources (1)   
·survival of the fittest /those best adapted to the environment survived (1)  
·those who survive pass their genes/characteristics onto their offspring (1)  
·natural selection (1)   
    (3) 

 Total for Question = 8 marks  

If you would like to learn more about the topics covered in this learning opportunity then follow the link below!

https://www.bbc.co.uk/bitesize/guides/zyv83k7/revision/1

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