UNIT 3.1

Question 1

food security

Answer 1

the availability of human pop to access food of sufficient quality and quantity

Question 1

food production must be

Answer 1

sustainable and not degrade the natural resources

Question 2

what Is food production ultimately dependent on

Answer 2

photosynthesis

Question 3

define a cultivar

Answer 3

as a plant or group of plants selected for desirable characteristics and easily propagated

Question 4

factors to increase food production include

Answer 4

• breeding of higher yielding cultivars
• use of fertiliser
• protecting crops from pests, diseases and competition

Question 5

to increase production, plant breeders seek to develop crops with

Answer 5

• higher nutritional value
• higher resistance to peer and diseases
• physical characteristics best suited to rearing and harvesting
• plants that can survive in particular environmental conditions

Question 6

why is livestock farming less efficient than crop farming and when is livestock farming useful

Answer 6

• livestock produces less food per unit area than plants due to the loss of energy between trophic levels (90% loss - 10% passed on)
• however livestock production may be possible in managed and wild habitats unsuitable for the cultivation of crops

Question 7

main photosynthetic pigments and what colours of the visible light spectra do they absorb

Answer 7

chlorophyll A + B
red and blue

Question 8

what is the advantage of accessory pigments

Answer 8

accessory pigments are consequently necessary since they aid in the absorption of light and the subsequent transfer of energy to a primary pigment such as chlorophyll

Question 9

energy from the food chain can be lost through

Answer 9

undigested food/waste
movement
maintaining body temp

Question 10

3 fates of of light hitting a leaf

Answer 10

transmitted
absorbed
reflected

Question 11

action spectra

Answer 11

shows the rate of photosynthesis at each light wavelength

Question 12

absorption spectra

Answer 12

shows the absorption of light of each wavelength of each pigment

Question 13

the light reaction

Answer 13

• light energy absorbed excites electrons in the pigment molecule
• the transfer of these electrons though the ETC releases energy to generate ATP by ATP synthase
• H.E.E passed along the transport chain, pumping H ions into grana
• hydrogen ions used by ATP synthase to make up ATP for carbon fixation
• energy also used to split water (photolysis) water to hydrogen and oxygen (O out of cell) hydrogen binds to NADP to make NADPH - as it can’t go on its own - to the next stag

Question 14

carbon fixation

Answer 14

• enzyme RUBisCO fixes to CO2 by attaching it to Ribulose Biphosphate (RUBP)
  = formation of intermediate
  3 phosphoglycerate (3PG)
• 3PG becomes phosphorylated by ATP to generate
  = Glyceraldehyde - 3 - phosphate
• G3P used to synthesis glucose or back to RUBP to repeat cycle

Question 15

fates of glucose

Answer 15

• structure
• storage
• respiration
• biosynthetic pathways