Unit 3 (lol) Flashcards
What is food security
Enabling human populations to access food of sufficient quality and quantity
Increase in human population leads to….
increased demand for food production
Food production must be …. and is dependent on …..
sustainable and not degrade the natural resources on which agriculture depends
dependent on photosynthesis
Examples of plant crops
Cereals, Plants, Roots and Legumes
What factors does food production depend on?
factors that control photosynthesis and plant growth
What does increased food production depend on?
Breeding of higher yield cultivars
Use of fertiliser
Protecting crops from plants and diseases
Competition
Breeders seek to develop crops with….
Higher nutritional values
Resistance to pests and diseases
Ability to thrive in particular environmental conditions
What happens to light energy at a leaf
Absorbed, transmitted and reflected
What is the principal photosynthetic pigment?
Chlorphyll a and b
Examples of accessory pigments
Carotenoids
Each pigment absorbs….
a different wavelength of light
What do accessory pigments do
extend the range of wavelength absorption and pass energy to chlorophyll for photosynthesis
What does an absorption spectrum show
the wavelengths of light absorbed by individual pigments
What does an action spectrum show
the rate of photosynthesis when specific wavelengths of light are supplied to photsynthetic pigments
What does absorbed light energy do to electrons
excites the electrons in the pigment molecule
