Learning activity

• Draw a very basic cow on the blackboard or use an OHT.

• The students should list improvements they might make to the cow to improve its milk yield. Ask them to draw the improvements on the board.

• They should then list improvements to increase its yield of meat. Again, ask students to draw their ideas on the board.

• Now compare these pictures with the original and ask the students which cow they would use to produce calves if they were a farmer. Why? The good characteristics will probably be passed on to the young. Discuss how over time this produces changes in the characteristics of that breed.

• Ask the class to draw up a chart of dogs with two columns: headed 'Use of the dog' and 'Traits for which you would selectively breed'.

Learning outcomes

• List favourable and unfavourable characteristics in farm animals.
  
• Explain how you could breed to obtain more favourable ones.
  
• Relate characteristics to use.

Extension work

• Disadvantages of artificial selection.
  
• Project on the development of modern apples from wild apples.