B1.4.2 - Photosynthesis Experiments Flashcards Preview

B1 - B2 > B1.4.2 - Photosynthesis Experiments > Flashcards

Flashcards in B1.4.2 - Photosynthesis Experiments Deck (16):
1

What can testing for starch prove?

That light, chlorophyll and carbon dioxide are essential for photosynthesis

2

What are the steps for testing for starch?

Get a leaf and use forceps to put it into a beaker of boiling water.
Then take the leaf and put it into a test tube with boiling ethanol.
Then wash the leaf with water and spread it out on a white tile.
Add a few drops of iodine solution, and the leaf should change colour.

3

Why should you use forceps to place the leaf into the boiling water?

So you don’t accidentally burn yourself.

4

Why do you need to place the leaf into the boiling water?

To kill it

5

Why do you need to place the leaf into boiling ethanol?

So the chlorophyll is removed

6

Why do you need to wash the leaf?

So you can remove the ethanol and soften it

7

What is iodine solution made of?

A mixture of iodine and potassium iodide

8

What colour should the leaf turn if starch is present?

Blue - black

9

What is a variegated leaf?

It is only coloured green in some areas

10

How can you prove chlorophyll is needed for photosynthesis?

Place a destarched variegated plant in sunlight for several hours. Then, test one of the leaves for starch.

11

Why do you need to destarch a plant before carrying out photosynthesis experiments?

So the starch can start from nothing

12

How can you destarch a plant?

You place it in total darkness for 24 hours

13

How can you prove light is needed for photosynthesis?

Get a destarched plant and cover one of its leaves with black card. Light can’t reach the area of this leaf. Place the plant in sunlight. Then, test the starch in the leaf.

14

How can you prove carbon dioxide is needed for photosynthesis?

Take a destarched bag and place it in a polythene bag. Before you seal the bag add a pot of soda lime. Place it in sunlight, and then test it for starch

15

What is soda lime?

A chemical that absorbs carbon dioxide and water

16

How can you prove oxygen is given off during photosynthesis?

Place an upturned test tube above an aquatic plant. Put the apparatus in light for maximum photosynthesis.
Once you have collected a full tube of gas, place a glowing splint inside the tube. It will relight because of the oxygen present.