Photosynthesis And Tropisms

Question 1

What is photosynthesis?

Answer 1

The way in which plants make their food

Question 2

What is the word equation for a the process of photosynthesis?

Answer 2

Carbon dioxide + water —–> light and chlorophyll = glucose + oxygen

Question 3

How do you show that starch is produced by a photosynthesising plant?

Answer 3

1. Place a plant in the dark for 48 hours to de-starch it
2. Cover part of a leaf with tin foil and leave the plant in bright light for 4-6 hours to photosynthesise
3. Remove the leaf with tin foil on it, remove the foil and put the leaf in a boiling water bath for one minute to kill the leaf
4. Half-fill a test tube with alcohol and insert the leaf
5. Heat the alcohol and leaf to remove the chlorophyll to make the iodine and starch reaction clearer
6. Dip the leaf back in the water bath then spread onto a white tile
7. Cover the leaf with iodine solution, the area where the foil was should be blue-black while the rest of the leaf should be brown-yellow

Question 4

What is a tropism?

Answer 4

The growth response of a plant to a stimulus

Question 5

What is a phototropism?

Answer 5

Growth response of a plant to light

Question 6

What is a geotropism?

Answer 6

Growth response of a plant to the force of gravity