CAIE A Level Biology 9700 · Selection and evolution
A dairy farmer has a herd of 100 cows with an average milk yield of 25 litres per day. He aims to increase the average milk yield to 35 litres per day over 10 generations. Describe the steps involved in a selective breeding programme to achieve this.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.