Plants

Question 1

Photosynthesis

Answer 1

Conversion of light energy to chemical energy
Basis of all food chains
Production of complex organic compounds from simple inorganic compounds

6CO2+6H2O=>C6H12O6+6O2

Question 2

Factors that affect rate of photosynthesis

Answer 2

Light
CO2
Temp

Question 3

How light affects photosynthesis

Answer 3

Increase light, increase rate up to a point
Only a certain amount of chloroplasts
Too much light, increased transpiration
Too much water loss leads to stomata closing, p stops as too much UV damages plants

Question 4

How CO2 affects rate of photosynthesis

Answer 4

Increase CO2, increase p up to a point
Amount of CO2 is fixed at 0.04%
Greenhouses can be pumped with CO2

Question 5

How temp affects rate of photosynthesis

Answer 5

Higher temp, increased rate of p

If above 40C, rate decreases, enzymes denature

Question 6

Features CO2 diffuse from air into chloroplasts

Answer 6

Open stomata, CO2 diffuses in
Air spaces in spongy mesophyll
LSA

Question 7

Feature of leaf for sunlight to get into palisade cell

Answer 7

Transparent upper epidermis
Tightly packed palisade cells full of chloroplasts
LSA

Question 8

Adaptations of leaf

Answer 8

LSA
Thin leaves
Leaves on leaf stalk
Waxy cuticle
Stomata
Transparent upper epidermis
Palisade layer with elongated cell
Spongy mesophyll with air spaces
Vascular tissue close by

Question 9

LSA of leaf

Answer 9

More sunlight absorption

Question 10

Thin leaves

Answer 10

Shorter distance for light, water and CO2 to travel

Question 11

Leaves grow on leaf stalk

Answer 11

Orientate themselves for max light absorption

Question 12

Waxy cuticle

Answer 12

Waterproof
Barrier to microbes
Reduce water loss by evaporation

Question 13

Stomata

Answer 13

Gas exchange

Question 14

Transparent upper epidermis

Answer 14

Allows light through to palisade cells

Question 15

Palisade layer with elongated cell

Answer 15

Tightly packed
Full of chloroplasts
Chloroplasts can move in cell

Question 16

Spongy mesophyll with air spaces

Answer 16

Gas exchange between atmosphere and leaf cells

Question 17

Vascular tissue close by

Answer 17

Transport of water to cells from root

Transport of products of photosynthesis away from leaf

Question 18

Mineral ions

Answer 18

Nitrate, amino acids
Stunted growth
Magnesium, chlorophyll
Yellow leaves
Phosphate, respiration, growth
Poor growth
Potassium, respiration, photosynthesis
Discoloured leaves

Question 19

Experiments to investigate photosynthesis

Answer 19

Pondweed under water, factors varied
Lamp distance, baking powder added,
White leaves plant tested against green leaves plant

Gas given off, bubbles counted
Speed of photosynthesis shown under different conditions

Question 20

Investigation to see if starch is produced in photosynthesis

Answer 20

Leave in dark for 24hrs, use up starch for respiration
Remove one leaf, boil, burst cell wall and cell membrane
In ethanol, dissolve chlorophyll
In cold water, leave to be pliable
White tile, iodine
Black=starch

Question 21

Respiration and photosynthesis

Answer 21

Resp, continuous process
Photo, light dependant
Net output at night, CO2

Question 22

Leaf adaptations for gas exchange

Answer 22

Thin
Stomata at lower epidermis
Guard cells

Question 23

Thin leaves

Answer 23

Gases diffuse in quickly

Question 24

Stomata at lower epidermis

Answer 24

Diffusion of gases

Question 25

Guard cells

Answer 25

Allow gases in

Question 26

Stomata and gas exchange

Answer 26

Stomata, holes Guard cells, regulate opening and closing of stomata, allow CO2, O2 exchange between leaf, atmosphere GC, absorb water, turgid, open Flaccid, close

Question 27

Investigations of light on net gas exchange from leaf

Answer 27

Hydrogen carbonate indicator Leaf to bung, put tube in different light intensities Observe colour change

Question 28

Plant response of stimuli

Answer 28

``` React to environmental changes, temp, light Receptors detect change Effectors carry out response Response, auxin, growth Phototropism, geotropism ```

Question 29

Auxin

Answer 29

Growth hormone Produced in tip Affects zone of elongation

Question 30

Geostropism

Answer 30

Root, positive Auxin falls due to gravity, inhibits growth Shoots, negative

Question 31

Phototropism

Answer 31

``` Stem, positive Auxin likes the shade Stimulates growth on shaded side Elongates Points towards sun ```

Question 32

Insect pollination

Answer 32

``` Scent Small amount of pollen Heavy pollen Large colourful petals Nectaries Small anthers Sticky pollen Small stigmas ```

Question 33

Wind pollination

Answer 33

``` Light pollen Pollen, smooth outer walls Green, small petals No nectaries No scent Large feathery stigma out of flower Large amount of pollen Large hanging anthers ```

Question 34

Pollination, fertilisation

Answer 34

Pollen grain on stigma Tube grows from 1 pollen grain pore, moves along style towards egg sac 1 pollen grain nuclei called tube nucleus controls tube growth Tube growth towards micropyle Tube nucleus joins other nuclei in egg sac Become endosperm Fertilisation, zygote formed Flower fades, plant produces fruit

Question 35

Conditions for seed germination

Answer 35

Water Warm temp Oxygen for resp

Question 36

Germinating seeds

Answer 36

``` Fertilised ovule, seed Ovary, fruit Zygote develops embryonic plant with radicle root and plumule Ovule contains cotyledons, food store Ovule wall, testa, seed coat Ovary wall, fruit coat ```

Question 37

Asexual reproduction

Answer 37

``` 1 parent Vegetative Root, leaf, stem grow into new plants Genetically identical Runners, strawberry Rhizomes, iris Corm, crocus Bulb, onion 2nd stem extends, specialise in root cells, daughter plant Cuttings in auxin, encourage ends, roots, placed in soil ```

Question 38

Sexual reproduction

Answer 38

2 parents Genetically unidentical Gametes

Question 39

Plant yield

Answer 39

Control all limiting factors, for optimum conditions | Polythene tunnels

Question 40

Increased CO2 and temp and crop yield

Answer 40

Polythene tunnels, increase heat, CO2 Reactions happen faster in increased heat and increased CO2 P produces energy, used for growth, higher yield

Question 41

Fertiliser, crop yield

Answer 41

NPK Amino acids Respiration Enzymes

Question 42

Pets control

Answer 42

Eat crops, cannot be sold | Pesticides reduce pests that reduce yield

Question 43

Chemical pesticides

Answer 43

``` Easy to apply Pests develop resistance Can kill helpful organisms too Poisonous to other organisms Bioaccumulation damage other organisms Can be adjusted for problems and soil type ```

Question 44

Biological pesticides

Answer 44

``` No poison No resistance May become a pest itself Difficult to apply May kill helpful organism Not suitable for all ```