t6 exam q

Question 1

explain the changes in algae in a lake in the UK around the months of February and June (3)

Answer 1

the number of algae increase. this is because of there are longer daylight hours due to summer season. so more photosynthesis can occur for growth

Question 2

in the photosynthesis practical with pondweed, bubbles can be different sizes and difficult to count. how could the experiment be changed (2)

Answer 2

use a gas syringe to measure volume of gas collected

Question 3

the leaves of small plants are green. describe how these plants make glucose (2)

Answer 3

they have chloroplasts that absorb sunlight and by photosynthesis convert it to glucose

Question 4

in the photosynthesis practical with pondweed, the temperature of the water increased when it was near to the light source. give one improvement that would reduce the effect of this (1)

Answer 4

use a heat shield / water bath

Question 5

in the photosynthesis practical, state 3 variables that need to be kept constant (3)

Answer 5

temperature of the water, start each experiment with the same amount of water + carbon dioxide