B8: Photosynthesis

Question 1

Where is the chloroplasts situated?

Answer 1

In the leaf

Question 2

Where is chlolorphll

Answer 2

Pigment inside

Question 3

What does photosythesis allow?

Answer 3

Plants to create their own food

Question 4

Where and when does photosythesis occur?

Answer 4

In the green parts of plants(chloroplasts which contain a green substance called chlorophyll)when there is light

Question 5

How is energy transferred during photosythesis.

Answer 5

Energy is transferred from the envriroment to the chloroplasts by light

Question 6

What is the energy used for?

Answer 6

To convert carbon dioxide and Water to glucose(a simple sugar) -oxygen is a by product

Question 7

What type of reaction is photosythesis?

Answer 7

Endothermic reaction

Question 8

What do endothermic reactions need?

Answer 8

An input of energy from the enviroment

Question 9

What is the word equation for photosythesis?

Answer 9

Carbon dioxide + water-light-glucose+ oxygen

Question 10

What is the symbol equation for photosytheis?

Answer 10

6CO2 + 6H2O-light- C6H12O6+6O2

Question 11

How can we tell if water molecules are being produced

Answer 11

Air bubbles

Question 12

What are 6 adaptations of the leaves for photosythesis?(so a plant can photosythesise as much as possible

Answer 12

• leaves are broad(bigger SA for light)
• leafes are thin(diffusion for gases are short)
• they contain chlorophyll in the chloroplasts to absorb light
• veins-water from the xylem
• air spaces allow CO2 to get into cells and oxygen to leave by diffusion
• guard cells open and close to regulate gas exchange

Question 13

What are 3 possible limiting factors of photosythesis?

Answer 13

• light(intensity)
• temperature(photosytheis is controlled by emzymes)
• carbon dioxide concentration(needed for photosythesis)

Question 14

When can a plant not make enough chlorphyll?

Answer 14

When it does not have enough minerals (esspecially magnesium)

Question 15

What does the inverse square law state?

Answer 15

As tne distance of light from the plant increases, the light intensity decreases

Light intensity= 1/distance squared

Question 16

What is the reverse of photosythesis?

Answer 16

Respiration

Question 17

Startch is ____ in water

Answer 17

Insoluble

Question 18

What is needed for plants to grow as fast as possible?

Answer 18

• warm enviroment
• plenty of light
• CO2
• water

Question 19

How manipulate the enviroment for plants?

Answer 19

Garden greenhouse

Question 20

How dpes a greenhouse affect the rate of photosythesis?

Answer 20

-the glass means the enviroment is much more controlled than in a feild

it increases the rate of photosythesis and allows us to plant crops that wouldn’t grow well pousidd

Question 21

Why is controlling everything important?

Answer 21

-it prevents natural limiting factors from the time of day(temperature, light ect)

Question 22

What is the name of the system that allows all limiting factors to be controlled?

Answer 22

Hydroponics

Question 23

Is keeping the conditions in greenhouses just right expensive?

Answer 23

Yes but less staff are needed and there a greater number of crops and the crops are cleaner(profit)

Question 24

Which chemical in the leaves is required for photosynthesis?

Answer 24

Chlorophyll

Question 25

In which cell organelle do the reactions of photosynthesis take place?

Answer 25

Chloroplast

Question 26

In which layer of the leaf does the most photosynthesis take place?

Answer 26

Palisade layer

Question 27

The diagram shows the experimental setup to investigate the effect of light intensity on the rate of photosynthesis. What is the function of the beaker of water?

Answer 27

Acts as a heat shield

Question 28

Why does temperature increase the rate of photosynthesis (up to a certain point)?

Answer 28

As temperature increases the rate of enzyme activity also increases.

Question 29

Look at the diagram. On focus eLearning you completed this practical to investigate the effect of light intensity on the rate of photosynthesis. Identify the independent variable in this investigation.

Answer 29

Distance the lamp is from the plant

Question 30

Look at the diagram. On focus eLearning you completed this practical to investigate the effect of light intensity on the rate of photosynthesis. Identify two control variables in this investigation.

Answer 30

- volume of water in the test tube | - concentration of carbon dioxide

Question 31

The graph shows the effect of temperature on the rate of photosynthesis. Explain why the the graph decreases to a rate of zero.

Answer 31

The enzymes have become denatured and can not longer catalyse the reactions.

Question 32

Point B on the graph is called the compensation point. This indicates where...

Answer 32

The rate of photosynthesis is equal to the rate of respiration.

Question 33

What type of reaction is phototythesis"

Answer 33

Endothermic