Plant Nutrition + Transport

Question 1

Where does photosynthesis occur

Answer 1

Chloroplasts

Question 2

Word equation for photosynthesis

Answer 2

Carbon dioxide + water —> glucose + oxygen

Question 3

Symbol equation for photosynthesis

Answer 3

6CO2 + 6H2O —> C6H12O6 + 6O2

Question 4

Factors effecting photosynthesis

Answer 4

Light intensity
CO2 concentration
Temperature

Question 5

How does light intensity affect photosynthesis

Answer 5

As light intensity increases, rate of photosynthesis increases
The graph levels off due to another factor becoming limiting

Question 6

How does CO2 concentration affect photosynthesis

Answer 6

As CO2 concentration increases, rate of photosynthesis increases
Graph levels off due to another factor becoming limiting

Question 7

How does temperature affect photosynthesis

Answer 7

As temperature increases photosynthesis increases, up until a certain point
If the temperature continues beyond this point, enzymes denature so the rate of photosynthesis rapidly decreases

Question 8

Name the parts of a leaf (9)

Answer 8

Waxy cuticle
Upper epidermis
Palisade mesophyll
Vascular bundle
Spongy mesophyll
Lower epidermis
Chloroplasts
Stomata
Guard cells

Question 9

Waxy cuticle

Answer 9

Reduce water loss by evaporation

Barrier to disease-causing microorganisms

Question 10

Upper epidermis

Answer 10

Thin and transparent
Allows sunlight to pass through to the palisade mesophyll layer for photosynthesis

Question 11

Palisade mesophyll

Answer 11

Contains many chloroplasts for absorbing light

Question 12

Vascular bundle

Answer 12

Contains xylem and phloem

Question 13

Spongy mesophyll

Answer 13

Main gas exchange surface
Absorbs CO2 and releases oxygen and water

Question 14

Lower epidermis

Answer 14

Protective layer
Contains more stomata to regulate water loss

Question 15

Chloroplasts

Answer 15

Site of photosynthesis

Question 16

Stomata

Answer 16

Regulates water loss
Site of gas exchange

Question 17

Guard cell

Answer 17

Controls opening and closing of stomata

Question 18

What does the xylem do

Answer 18

Carry water and mineral salts from roots to shoots via the transpiration stream

Question 19

What does the phloem do

Answer 19

Transport sugars (like sucrose) and amino acids from where the are made in the leaves to the other parts of the plant
This movement of substances is called translocation

Question 20

Root hairs

Answer 20

Root hairs take in water
Each cell on the plants roots fro long hairs which stick out from the soil
Each branch will have millions of these hairs
This increases the SA for absorbing water
Usually a high water concentration in the soil - therefore water moves into root hair cell via osmosis

Question 21

Transpiration definition

Answer 21

The loss of water from a plant

Question 22

What causes transpiration

Answer 22

Evaporation and diffusion

Question 23

Where does the most transpiration occur

Answer 23

Leaves

Question 24

What does transpiration cause

Answer 24

A shortage of water in the leaf
Therefore more water is drawn up by the rest of the plant through the xylem
Therefore more water is drawn up by the roots and there is a constant transpiration stream

Question 25

How does water escape a plant

Answer 25

There’s more water inside the plant than outside so water escapes through the stomata via diffusion

Question 26

What 4 factors effect the rate of transpiration

Answer 26

Light intensity Temperature Wind speed Humidity

Question 27

How does light intensity affect transpiration

Answer 27

The brighter it is, the faster the rate of transpiration This is because the stomata open to allow CO2 to enter for photosynthesis

Question 28

How does wind speed affect transpiration

Answer 28

The higher the wind speed the greater the transpiration rate This is because the wind removes water vapour from the leaf

Question 29

How does temperature affect transpiration

Answer 29

Higher temperature means faster rate of transpiration This is because particles have more kinetic energy to evaporate and diffuse out via the stomata

Question 30

How does humidity affect the rate of transpiration

Answer 30

The higher the humidity, the lower the rate of transpiration This is because the air around the leaf is already saturated

Question 31

Why do plants need nitrates + deficiency

Answer 31

Contains nitrogen for making amino acids and proteins - needed for cell growth Deficiency: will be stunted, older leaves will turn yellow

Question 32

Why do plants need phosphates + deficiency

Answer 32

Contains phosphorus for making DNA and cell membranes and they are needed for respiration and growth Deficiency: poor root growth, older leaves turn purple

Question 33

Why do plants need potassium + deficiency

Answer 33

Help enzymes needed for photosynthesis and respiration Deficiency: poor flower and fruit growth, discoloured leaves

Question 34

Why do plants need magnesium + deficiency

Answer 34

Makes chlorophyll for photosynthesis Deficiency: yellow leaves

Question 35

Equipment used to estimate transpiration rate

Answer 35

Potometer

Question 36

Potometer method

Answer 36

1. Cut a shoot underwater to prevent air entering the xylem. Cut at a slant to increase SA available for water uptake 2. Assemble potometer in water and insert shoot underwater so no air enters 3. Remove apparatus from water but keep the end of the capillary tube submerged in a beaker of water 4. Check apparatus is water and air tight 5. Dry the leaves, allow time for shoot to acclimatise and then shut the tap 6. Remove end of capillary tube from water until one air bubble has formed, then put back into water 7. Rec starting position of air bubble 8. Start a stopwatch and rec distance moved by air bubble per unit time (e.g. an hour) 9. keep conditions constant throughout e.g. temp, humidity

Question 37

Potometer - light intensity

Answer 37

Lamp - increases transpiration rate Put potometer in cupboard - decreases transpiration rate

Question 38

Potometer - temperature

Answer 38

Put in a room that is hotter/colder Increase in temp - increase transpiration rate vice versa

Question 39

Potometer - humidity

Answer 39

Spray water into a clear plastic bag before sealing it around the plant to increase humidity - decrease rate transpiration

Question 40

Potometer - wind speed

Answer 40

Fan increases wind speed - increases transpiration rate