9700/13 Biology Oct Nov 2013 Online Test | Cambridge AS and A Level MCQ

The graph shows the results of a study to determine whether there is a link between the number of cigarettes smoked by a mother and the birth weight of her baby.
Which conclusions can be drawn from this graph?
1 As the number of cigarettes smoked increases, the weight of the baby always decreases.
2 Factors, other than smoking, affect the birth weight of a baby.
3 Nicotine, tar and carbon monoxide slow the growth…