Biodiversity & Photosynthesis 3: Photosynthesis.

Question 1

What is photosynthesis?

Answer 1

It is a chemical reaction that plants use light energy to make their own food.

Question 2

What is the name of the food that plants make by photosynthesis

Answer 2

Glucose.

Question 3

Write down the photosynthesis word equation

Answer 3

Water + Carbon dioxide –> Oxygen + Glucose

Question 4

What are the raw materials for photosynthesis?

Answer 4

Water and Carbon dioxide

Question 5

What are the products for photosynthesis?

Answer 5

Glucose and Oxygen

Question 6

What are the other two essential requirements for photosynthesis to happen.

Answer 6

Light energy from the sun and Chlorophyll which is found in the chloroplasts

Question 7

What goes a plant use the glucose it makes during photosynthesis for?

Answer 7

1.Building cellulose for growth
2. Cellular respiration of plant cells
3. Stores some as starch

Question 8

What is the name of the experiment that proves photosynthesis has happened.

Answer 8

Testing a leaf for starch

Question 9

What is the test for starch - what result would you expect to see if starch was present?

Answer 9

Drop iodine solution onto a prepared leaf.
If starch is present the iodine solution will turn from light brown to black.

Question 10

When testing a leaf for starch why do we boil the leaf in water?

Answer 10

It softens the leaf and burst the cell membranes

Question 11

When testing a leaf for starch why do we boil the leaf in alcohol.

Answer 11

It bursts open the chloroplasts to release chlorophyll inside (that’s why the alcohol turns green).

Question 12

Before we use the alcohol what must we do and why.

Answer 12

Turn all Bunsen burners off as alcohol has a low boiling point and is VERY Flammable

Question 13

When testing a leaf for starch what other safety precautions must we do?

Answer 13

Tie hair back and wear safety goggles.
Also never leave a Bunsen unattended

Question 14

How might we prove a plant needs water to photosynthesise?

Answer 14

Have 2 plants water one as normal, but deprive the other of water for a while and then test both for the presence of starch.

Question 15

How might we prove a plant needs light to photosynthesise?

Answer 15

Have 2 plants one gets light as normal, but deprive the other (put in a dark cupboard for a while) and then test both for the presence of starch.

Question 16

When we try to prove a plant needs water or like to photosynthesise why do we always have a normal one too?

Answer 16

IT IS CALLED A CONTROL. A control is a point of comparison against which other test results are measured. It proves the one thing you have changed, is what is actually causing the result.