Food Supply, Plant Growth and Productivity

Question 1

Absorption

Answer 1

Process by which light is taken in and retained by a leaf.

Question 2

Absorption spectrum

Answer 2

Display/graph showing the quantity of light absorbed by a pigment at different wavelengths of light.

Question 3

Action spectrum

Answer 3

Graph showing the rate of photosynthesis by a green plant at different wavelengths of light.

Question 4

Carbohydrates

Answer 4

Large group of organic compounds that contain carbon, hydrogen and oxygen.

Question 5

Carotenoids

Answer 5

Yellow pigments which absorb light and pass the energy to chlorophyll.

Question 6

Chlorophylls

Answer 6

Green pigments which absorb light in the red and blue regions of the spectrum.

Question 7

Chromatography

Answer 7

Technique used to separate the components of a mixture that differ in their degree of solubility in a solvent.

Question 8

Cultivar

Answer 8

Variety of plant obtained from natural species by selection and/or genetic manipulation and maintained by cultivation.

Question 9

Food security

Answer 9

Ability to access food of adequate quantity and quality.

Question 10

Nanometre

Answer 10

One thousand-millionth of a metre.

Question 11

Photosynthesis

Answer 11

Process by which green plants trap light energy and use it to produce carbohydrates.

Question 12

Reflection

Answer 12

Process by which light bounces off a leaf surface.

Question 13

Transmission

Answer 13

Process by which light passes through a leaf.

Question 14

Trophic

Answer 14

Term referring to a level in a food chain or pyramid.

Question 15

ATP

Answer 15

High energy compound which provides the energy needed to drive the Calvin cycle.

Question 16

ATP synthase

Answer 16

Enzyme which catalyses the synthesis of ATP from ADP and Pi.

Question 17

Calvin cycle

Answer 17

Second stage of photosynthesis during which carbon dioxide is taken up and sugar is synthesised.

Question 18

Carbon dioxide

Answer 18

Raw material which supplies carbon atoms to be fixed into carbohydrates.

Question 19

Electron transport chain

Answer 19

Group of protein molecules in the membrane of a chloroplast which makes energy available to pump hydrogen ions across the membrane and to split water molecules.

Question 20

Glyceraldehyde-3-phosphate (G3P)

Answer 20

Metabolite in the Calvin cycle used to regenerate RuBP and make sugar.

Question 21

Hydrogen

Answer 21

Product of photolysis of water which becomes attached to NADP.

Question 22

Light-dependant reaction

Answer 22

First stage of photosynthesis during which light energy is converted to chemical energy.

Question 23

NADP

Answer 23

Compound which accepts hydrogen released during the photolysis of water.

Question 24

Oxygen

Answer 24

Product of photolysis of water which is required for aerobic respiration.

Question 25

Photolysis

Answer 25

Breakdown of water during the light-dependant stage of photosynthesis.

Question 26

Ribulose biphosphate (RuBP)

Answer 26

Metabolite in the Calvin cycle which acts as the carbon dioxide acceptor.

Question 27

Rubisco (RuBisCO)

Answer 27

Enzyme which fixes carbon dioxide by attaching it to RuBP.

Question 28

Water

Answer 28

Raw material which becomes split into oxygen and hydrogen during photolysis.