20 mustard seeds were placed on wet filter paper in six Petri
dishes. Each dish was kept at a different temperature.
After four days the numbers of seeds germinating was
counted. The results are given in the table below:
Number of seeds placed in each dish
Number of germinating seeds
15 ÷ 20 x 100 = 75
(a) Complete the last column by calculating the percentage
germination of the seeds. (The last one has been done
for you as an example.)
(b) Which is the best temperature for germinating these seeds?
(c) What happens to the seeds when the temperature is hot or cold? Try to explain your observation.
(d) Why were 20 seeds put in each dish and not just one seed per dish?
(e) (i) What other factors may affect the germination of
the seeds? (List three)
(ii) Chose one of these other factors and say how
you might investigate its effect on the germination of