6) Plant Structure & Function

Question 1

Where does photosynthesis take place?

Answer 1

In chloroplasts

Question 2

What type of reaction is photosynthesis?

Answer 2

Endothermic (needs energy)

Question 3

What is the energy source of photosynthesis?

Answer 3

Sunlight

Question 4

What traps sunlight in chloroplasts?

Answer 4

The chemical chlorophyll

Question 5

What is sunlight used to make?

Answer 5

Carbohydrates

Question 6

What is the balanced chemical equation for photosynthesis?

Answer 6

6CO2 + 6H20 –> C6H12O6 + 6O2

Question 7

What factors affect the rate of photosynthesis?

Answer 7

Carbon dioxide concentration
Chlorophyll concentration
Light intensity
Temperature

Question 8

What happens in photosynthesis when light intensity increases above a certain threshold?

Answer 8

Rate no longer increases

Question 9

What happens in photosynthesis when carbon dioxide concentration increases above a certain threshold?

Answer 9

Rate no longer increases

Question 10

Why does increased temperature increase the rate of photosynthesis?

Answer 10

More energy is provided

Question 11

What happens to photosynthesis when temperatrue increases above 45 degrees C?

Answer 11

Enzymes denature and rate of reaction sharply drops and stops

Question 12

What is the temperature plant enzymes denature above?

Answer 12

45 degrees C

Question 13

What is the limiting factor of photosynthesis in winter?

Answer 13

Temperature

Question 14

What is the limiting factor of photosynthesis at night?

Answer 14

Light intensity

Question 15

What is the limiting factor of photosynthesis in mineral deficient soil?

Answer 15

Chlorophyll concentration

Question 16

How can you test the effect of light intensity on the rate of photosynthesis?

Answer 16

Change distance between lamp and pondweed and count oxygen bubbles produced

Question 17

What are the gas bubbles pondweed produce?

Answer 17

Oxygen bubbles

Question 18

What is the independent variable when investigating light intensity?

Answer 18

Light intensity

Question 19

What is the dependent variable when investigating light intensity?

Answer 19

Number of bubbles

Question 20

What is the inverse square law?

Answer 20

Light intensity = 1 / distance^2

Question 21

What is accuracy?

Answer 21

How close a measured value is to its true value

Question 22

What is reliability?

Answer 22

The ability of an experiment to produce consistent results

Question 23

What is validity?

Answer 23

How appropriate an experimental method is at achieving the aim of an experiment

Question 24

What do root hair cells do?

Answer 24

Take in the minerals plants need to survive

Question 25

How are root hair cells specialised?

Answer 25

Long projections | No chloroplasts

Question 26

Why do root hair cells have long projections?

Answer 26

To increase the surface area for absorbing water and minerals

Question 27

WHy don't root hair cells have chloroplasts?

Answer 27

They are located underground and do not receive sunlight

Question 28

What do xylem cells transport?

Answer 28

Water up the stem into the leaves

Question 29

What direction do xylem cells transport water?

Answer 29

Up the plant | Stem to leaves

Question 30

What are xylem vesslels made from?

Answer 30

A series of connected dead xylem cells

Question 31

Why can water move through dead xylem cells?

Answer 31

The end walls are broken (open-ended)

Question 32

What substance strengthens the cell walls of xylem cells?

Answer 32

Lignin

Question 33

What cells open and close the stomata?

Answer 33

Guard cells

Question 34

What are stomata?

Answer 34

Gaps in the lower epidermis of leaves

Question 35

Where are stomata found?

Answer 35

The lower epidermis of leaves

Question 36

What do stomata do?

Answer 36

Facilitate the diffusion of gases (evaporatd water) in and out of leaves

Question 37

How do guard cells open the stomata?

Answer 37

They take up lots of water causing them to swell

Question 38

How do guard cells close the stomata?

Answer 38

They lose water and return to a limp state

Question 39

What balance do stomata reach?

Answer 39

Allowing gases for photosynthesis into leaves and conserving water

Question 40

What happens to the stomata when water is abundant?

Answer 40

Stomata opens to allow gases for photosynthesis to move freely in and out of the leaf

Question 41

What happens to stomata when water is scarce?

Answer 41

Stomata close to prevent further water loss

Question 42

What is the state of stomata at night and why?

Answer 42

Closed as no carbon dioxide is needed for photosynthesis as there is no sunlight