Plant nutrition - Unit 3

Question 1

what is photosynthesis

Answer 1

Photosynthesis describes the process by which plants use light energy to produce glucose.

Question 2

Palisade mesophyll cells are adapted for photosynthesis by…?

Answer 2

having lots of chloroplast

Question 3

what is most likely to affect the rate of photosynthesis

Answer 3

change if temperature

Question 4

Photosynthesis converts..?

Answer 4

Light energy into chemical energy

Question 5

Why do plants need magnesium

Answer 5

to make chlorophyll

Question 6

What do phloem vessels transport?

Answer 6

sucrose

Question 7

If there is no starch in a leaf, this suggests

Answer 7

The leaf has not been able to photosynthesise

Question 8

how the waxy cuticle on the surface of a leaf aids efficient photosynthesis

Answer 8

It helps to reduce water loss by evaporation

Question 9

what happens to the rate of photosynthesis if a plant is put in a dark place?

Answer 9

it will stop as there is no light energy available for photosynthesis

Question 10

2 other factors that can affect the rate of photosynthesis

Answer 10

Temperature

Water availability

Question 11

why unicellular organisms can rely on diffusion to move substances in and out of a cell

Answer 11

Because substances only have small distances to travel, so the diffusion rate is quick enough.

Question 12

the word equation for photosynthesis

Answer 12

Carbon dioxide + water → Glucose + Oxygen

Question 13

the balanced equation for photosynthesis

Answer 13

6 CO2 + 6 H2O → C6H12O6 + 6 O2

Question 14

where does photosynthesis occur

Answer 14

in chloroplasts

Question 15

what do plants need glucose for, name 5

Answer 15

respiration 
stored as starch 
make amino acids 
make cellulose for cell walls
make lipids

Question 16

light intensity

Answer 16

Limiting as it provides energy
Increasing light intensity increases
Rate of photosynthesis, while it does this,light is the limiting factor (while the graph increases)
After a point, it no longer increases rate of photosynthesis, another factor has become limiting
(CO2 or temp - when the graph is constant)

Question 17

carbon dioixide

Answer 17

Limiting as it is a reactant
Increasing CO2 increases rate of
photosynthesis, while it does this, CO2 is the limiting factor (while the graph increases)
After a point, it no longer increases rate of photosynthesis, another factor has become limiting
(light or temp - when the graph is constant)

Question 18

temperature

Answer 18

Limiting as it affects enzymes
Increasing temp at first increases rate
of photosynthesis, as enzymes / particles have more energy (collide more)
It reaches an optimum for rate of photosynthesis
At too high temps, enzymes denature (active site changes shape) so rate decreases.

Question 19

where is starch stored

Answer 19

in cells which can photosynthesise

Question 20

prove chlorophyll is neaded for photosynthesis

Answer 20

No starch as white parts of the leaf do not contain chlorophyll, so do not photosynthesise, so do not produce glucose to store as starch.

Question 21

name 1 leaf adaptation

Answer 21

large area to absorb more light

Question 22

name another leaf adaptation

Answer 22

waxy cuticle to prevent water loss

Question 23

name another leaf adaptation

Answer 23

Upper epidermis transparent

Question 24

name another leaf adaptation

Answer 24

Palisade cells near surface and tightly packed, to absorb as much light as possible

Question 25

name another leaf adaptation

Answer 25

Air spaces to allow movement of carbon dioxide

Question 26

name another leaf adaptation

Answer 26

Vascular bundle where water transported to leaf in the xylem

Question 27

name another leaf adaptation

Answer 27

Stomata (holes in the bottom of the leaf) which allow CO2 to diffuse into the leaf

Question 28

name another leaf adaptation

Answer 28

Guard cells to open stomata in day for photosynthesis, and close them at night to prevent water loss.

Question 29

where does gas exchange occur

Answer 29

in plants occurs through stomata.

Question 30

why do plants need co 2

Answer 30

for photosynthesis and to produce oxygen

Question 31

why do plants need oxygen

Answer 31

plants need oxygen for respiration (aerobic) and to produce carbon dioxide