3.1

Question 1

Food security

Answer 1

Ability of human populations to access food of sufficient quality and quantity

Question 2

Food production can be increased by

Answer 2

Breeding of higher yielding cultivars

Use of fertilisers

Protect crops from pests, disease and competition

Question 3

Fates of light energy can be

Answer 3

Reflected

Absorbed by photosynthetic to generate ATP

Transmitted

Question 4

Each photosynthetic pigment ___________ of light

Answer 4

Absorbs different wavelengths. The absorption spectra shows the wavelength that each pigment absorbs

Question 5

Carotenoids

Answer 5

Extend the range of wavelengths absorbed and pass the energy to chlorophyll for photosynthesis

Question 6

Action spectra

Answer 6

Shows the range the relative rate of photosynthesis at a different wavelength of light

Question 7

Photolysis

Answer 7

1) light energy is absorbed by the chlorophyll creating high-energy electrons
2) Electrons passed along transport chain, plumping H+ ions into the grana, releasing energy
3) Hydrogen ions used by ATP Synthase to make for carbon fixation
5) Hydrogen picked by NADP to make NADPH for carbon fixation

Question 8

Carbon fixation

Answer 8

1) CO2 enters the cycle and is fixed by combining with RuBP
2) This reaction is controlled by the enzyme Rubisco
3) The CO2 and RuBP combine to make an intermediate compound, 3-phosphoglycerate
4) This joins with the H from NADPH and is phosphorylated by the add of Pi from ATP
5) This produces G3P- some is used to regenerate RuBP to continue the cycle
6) The rest is used to synthesise glucose

Question 9

Uses of sugar

Answer 9

Respiration
Starch
Cellulose
Biosynthesis pathways- fats and oils, proteins, nucleic acids

Question 10

Limiting factors

Answer 10

Temperature, light intensity, carbon dioxide concentration