Tomato plants are originally from South America. Tomato plants are often infected with a virus called ‘mosaic virus’. Plants that are infected have yellow patches on the leaves, and the younger leaves are twisted. The whole plant does not grow very tall. Some tomato plants, by chance, happen to be less severely affected by mosaic virus than others. We
say that these plants are more ‘resistant’. In an experiment, a large number of tomato plants were infected with mosaic virus. After a few months, the plants were examined to see how badly they were affected. The amount of yellow on their leaves was measured as a percentage. A graph of the results is shown on the right.
1 a State four examples of variation described in the passage.
b Choose one of your examples that could be an example of environmental variation and describe its cause.
c Choose one of your examples that could be an example of inherited variation and describe
its cause. Use the term ‘genetic information’ in your answer.
(Needs answering as soon as possible.)
