What can you say about the differences in the lengths of the dandelion leaves from the two efferent habitats? 0 -The leaves growing on the lawn have a smaller standard deviation than the ones growing on the wasteland. The graph of the lawn dandelions would have a tall and narrow variation curve while the other one would have a flatter and wider curve. Also the error bars on the dandelions growing on the wasteland would be bigger in length than the ones on the lawn. 8 Salmon live and reproduce in two rivers in Norway – the Names and Gaul rivers.

Data were collected on the umber of eggs laid by the salmon in these two rivers. In the River Names, the mean number laid was 1200 eggs per salmon and the standard deviation was 45. For the River Gaul, the mean was 770 eggs per salmon and the standard deviation was 48. Is there a difference between the number of eggs laid by the fish in the two different rivers? -Yes, the salmon living in the Names river lays on average 430 more eggs than the ones that live in the Gaul rivers. Over a period of 20 years, the umber of elephants in the More game reserve in Botswana was recorded each year. Data were also collected on the number of fallen and broken trees. The data are shown on the graph on the right. A State the trend shown by the graph. -Positive correlation b What can you say about the relationship between the two sets Of data? 0 -We can be sure that both sets of the data are linked with each other and so it is a casual relationship. This is because we can find a cause of the trend in both data.

Elephants re strong big animals and can easily break down branches of trees or even destroy them. If there are more elephants then more trees can be broken down by them. 10 Dung beetles collect fresh dung in which to lay their eggs. There are two groups – those that bury dung (bruises’),and those that roll away balls of dung (rollers’). An investigation was carried out to see if there was any difference in the quantity