Food Supply, Plant Growth and Productivity Flashcards
What are the 3 aspects of food security?
- Access to food
- Quantity of food
- Quality of food
What has caused a demand for increased food production?
Increase in human population & concern for food security
What process is all food production ultimately dependent on?
Photosynthesis
Give some examples of plant crops.
cereals, potato, roots and legumes.
State some factors that will increase food production.
- breeding for higher yielding cultivars
- use of fertiliser
- protecting crops from pests, disease & competition
Why do livestock produce less food per unit area than crop plants?
Due to the energy loss between trophic levels (90% loss)
What is the advantage of livestock production?
Not all land is suitable for growing crops
State 2 reasons why light energy is absorbed by photosynthetic pigments.
Generate ATP and photolysis
What are 2 possible consequences of light energy that is not absorbed?
Reflected or transmitted
Name the 2 main pigments found inside chloroplasts.
Chlorophyll a and chlorophyll b
Which 2 colours are mainly absorbed by chlorophyll a and b?
red and blue wavelengths
Name the 2 pigments that make up the carotenoids.
carotene and xanthophyll
What is the advantage to plants of having carotenoids?
They extend the range of wavelengths absorbed and pass the energy to chlorophyll for photosynthesis.
What effect does absorbed light energy have on the pigment?
it excites electrons in the pigment molecule
What happens to these excited electrons?
They pass through the electron transport chain