Topic 3

Question 1

Photosynthesis word equation

Answer 1

Carbon dioxide + Water -> Glucose + Oxygen
in the prescence of light and chlorophyll

Question 1

Photosynthesis definition

Answer 1

The process by which plants synthesis carbonhydrates from raw materials using energy from light

Question 2

Photosynthesis chemical equation

Answer 2

6CO^2 + 6H^2O -> C^6H^12O^6 + 6O^2

Question 3

5 uses of carbonhydrate

Answer 3

1) Starch as energy store (Long chains of glucose)
2) Cellulose to build cell wall
3) Used for respiration to provide energy (Same as animals)
4)Sucose for transport in phloem
5) Converted to nectar and attracts pollinators

Question 4

Leaf adaptations [2]

Answer 4

Large surface area
Very thin - aid diffusion

Question 5

Define chlorophyll

Answer 5

Green pigment found in chloroplast

Question 6

What does chlorophyll do

Answer 6

transfers energy from light
into energy in chemicals, for the synthesis of
carbohydrates

Question 7

Explain importance of nitrate ions for making amino acids [2]

Answer 7

1) Nitrate ions is needed to make amino acids
2)Amino acids is needed to make protein for growth

Question 8

What happens when plants are nitrate deficent [2]

Answer 8

1) Stunted growth
2) Yellowing leaves

Question 9

Explain importance of magnesium ions for making chlorophyll [2]

Answer 9

1) Magneisum ions are needed to make chlorophyll
2) Chlorophyll is needed to absorb light for photosynthesis

Question 10

Why can’t leaf be tested for glucose

Answer 10

Glucose is quickly used, converted and tranported, or turned into starch

Question 11

Where is starch stored

Answer 11

Chloroplast

Question 12

Investigating the Need for Chlorophyll

Answer 12

1) leaf is dropped in boiling water to kill and break down the cell membranes
2) The leaf is left for 5-10 minutes in hot ethanol in a boiling tube. This removes the chlorophyll so colour changes from iodine can be seen more clearly
3) The leaf is dipped in boiling water to soften it
The leaf is spread out on a white tile and covered with iodine solution
4) In a green leaf, the entire leaf will turn blue-black as photosynthesis is occurring in all areas of the leaf

Question 13

Define limiting factor

Answer 13

something present in the environment in such short supply that it restricts life processes

Question 14

3 factors that limit photosynthesis

Answer 14

1) Temperature
2) Light intensity
3) Carbon dioxide concentration

Question 15

The effect of temperature on the rate of photosynthesis [2]

Answer 15

1) As temperature increases the rate of photosynthesis increases as the reaction is controlled by enzymes
2) the enzymes begin to denature and the rate of reaction decreases as temperature is higher the optimum temperature

Question 16

the effect of light intensity on the rate of photosynthesis

Answer 16

1) The more light a plant receives, the faster the rate of photosynthesis
2) This trend will continue until some other factor required for photosynthesis prevents the rate from increasing further because it is now in short supply

Question 17

The effect of carbon dioxide concentration on the rate of photosynthesi

Answer 17

1) The more carbon dioxide a plant absorbs, the faster the rate of photosynthesis
2) This trend will continue until some other factor required for photosynthesis prevents the rate from increasing further because it is now in short supply

Question 18

Wax cuticle

Answer 18

Protective layer on top of the leaf, prevents water from evaporating

Question 19

Upper epidermis

Answer 19

Thin and transparent to let light enter palisade mesophyll layer underneath it

Question 20

Palisade mesophyll

Answer 20

column shaped cells tightly packed with chloroplasts to absorb more light, maximising photosynthesis

Question 21

Spongy mesophyll

Answer 21

Contains internal air spaces that icnreases the surface area to volume ratio for the diffusion of gases (Mainly carbon dioxide)

Question 22

Lower epidermis

Answer 22

Contains guard cells and stomata

Question 23

Guard cell

Answer 23

absorbs and loses water to open and close the stomata to allow carbon dioxide to to diffuse in, oxygen to diffuse out

Question 24

Stomata

Answer 24

1) gas exchange; opens during the day, closes during the night.
2) Evaporation of water takes place here
3) greater concentration on the underside of leaf to reduce water loss

Question 25

vascular bundle

Answer 25

Contain xylem and phloem to transport substance to and from the leaf

Question 26

Xylem

Answer 26

transports water into the leaf for mesophyll cells to use in photosynthesis and for transpiration from tomata

xylem closest to water in alphabet

Question 27

Phloem

Answer 27

transport sucrose and amino acid around the plant

ph sounds like food

Question 28

Large surface area (Leaf) adaptation

Answer 28

increases surface area for the diffusion of carbon dioxide and absorption of light for photosynthesis

Question 29

Thin adaptation

Answer 29

Allows carbon dioxide to diffuse to palisade mesophyll cell quickly

Question 30

Chlorophyll adaptation

Answer 30

Absorbs light energy so that photosynthesis can take place

Question 31

Net work of veins

Answer 31

Allows the transport of water to the cell of the leaf and carbon hydrates from the leaf for photosynthesis (Water for photosynthesis, carbon hydrates as the product of photosynthesis)

Question 32

Stomata adaption

Answer 32

Allows carbon dioxide to diffuse into the leaf and oxygen to diffuse out

Question 33

Epidermis is thin and transparent

Answer 33

Allows more light to reach the palisade cell

Question 34

Thin cuticle made of wax

Answer 34

To protect the leaf without blocking sunlight

Question 35

Palisade cell layer at the top of the leaf

Answer 35

Maximises the absorption of light as it will hit chloroplasts in the cell directly

Question 36

Spongy layer adaptation

Answer 36

Air space allows carbon dioxide to diffuse through the leaf, increasing the surface area

Question 37

Vascular bundle adaptation

Answer 37

thick cell walls of the tissue in the bundles to support the stem and leaf

Question 38

Usage of lipids in plant

Answer 38

1) Lipids is an energy source in seeds
2) synthesis new cellular material eg. membranes

Question 39

Light and dark conditions on gas exchange in an aquatic plant using hydrogencarbonate indicator solution

Answer 39

1) Net intake of carbon dioxide and a net output of oxygen
2) carbon dioxide is an acidic gas when dissolved in water
3) Hydrogencarbonate indicator shows the carbon dioxide concentration in solution

Question 40

Concentration of carbon dioxide

Answer 40

Highest: Yellow
Atmospheric: red
Lowest: Purple

Question 41

Iodide test [3]

Answer 41

for starch
Yellow/brown if not
blue/black if starch

Question 42

Why It is necessary to have a large surface area in the spongy mesophyll layer and lower epidermis? [3]

Answer 42

1) Fast gas exchange, more movement of gas by dffusion
2) Diffusion allows the aborption of carbon dioxide
3) Carbon dioixde is needed in photosynthesis

Question 43

Plants growing in soil lacking magnesium struggle to photosynthesise and therefore do not grow to their full potential because [4]

Answer 43

1) Magnesium is needed to synthesise chlorophyll
2) Chlorophyll absorbs light to provide energy needed for photosynthesis
3) Less light absorbed means less glucose synethesised
4) less respiration and therefore less energy is released for growth