Practical questions paper 1

Question 1

How can you show energy is being released during respiration

Answer 1

-Use a thermometer to check if the temperature of the flask has increased.

Question 2

Why are pea seeds soaked in Milton solution

Answer 2

it is a preservative and it kills bacteria.

Question 3

Describe the onion epidermis practical for osmosis

Answer 3

-Cut a thin layer of an onion epidermis
-Place in different concentrations of sucrose solution
-Observe changes under a microscope

Question 4

Why is a leaf placed in boiling water when experimenting photosynthesis

Answer 4

-To stop any chemical reactions from occuring inside the leaf

Question 5

Why is a leaf placed in hot ethanol when investigating photosynthesis

Answer 5

-To remove any chlorophyll, leaf turns a white-ish colour

Question 6

Why is the leaf rinsed when investigating photosynthesis

Answer 6

-It is rinsed in cold water and iodine is added to see if starch is present

Question 7

What colour does the leaf turn if starch is present

Answer 7

The parts of the leaf that contain starch turn blue-black.

Question 8

What is the role of the soda lime when investigating photosynthesis?

Answer 8

-It absorbs carbon dioxide to see if it is needed for photosynthesis.