U3 KA1 Flashcards
1
Q
What is food security?
A
- the ability of human populations to have access to food of sufficient quality and quantity.
2
Q
What is 1 global concern for food security?
A
- rapidly increasing global population, and increasing demand for food production.
3
Q
How is food production increased? (3)
A
- through the breeding of higher breed cultivators.
- use of fertilisers.
- protection of crops from pests and diseases.
4
Q
What are the limiting factors of agricultural production? (5)
A
- soil moisture, temperature, light availability, nutrient availability, pests.
5
Q
How can agriculture production be improved? (3)
A
- using pesticides and fertilisers.
- breeding higher yield cultivars.
- crop protection.
6
Q
What is a trophic level?
A
- an organisms place on the food web.
- eg. producer, primary consumer, etc.
7
Q
Why are crops grown instead livestock?
A
- growing crops is more efficient, as over 90% of energy is lost between trophic levels.
8
Q
Why is livestock produced instead of crops?
A
- livestock production is possible in areas that plants cannot grow.
9
Q
What is photosynthesis?
A
- the process by which green plants take energy from sunlight, converting it to sugar.
10
Q
What is chlorophyll A?
A
- the main pigment found in chloroplasts of plants that absorb light energy.
11
Q
What is the role of chlorophyll B and carotenoids?
A
- to absorb light from other wavelengths, passing the energy to chlorophyll A.
- this allows the chloroplast to extend the range of absorbed wavelengths.
12
Q
What happens to the light that is not absorbed by the plant? (2)
A
- reflected off the leaf.
- transmitted through the leaf.
13
Q
What happens in stage 1 of Photosynthesis? (2)
A
- light is absorbed by pigments, exciting electrons.
- electrons are transferred through ETC, releasing energy used for Photolysis.
14
Q
What happens in Photolysis?
A
- energy from ETC is used to split water into hydrogen and oxygen.
- hydrogen ions react with NADP to form NADPH.
15
Q
What happens in carbon fixation?
A
- Co2 is combined with RuBP by the enzyme RuBisCO, to form 3PG.
- ATP phosphorylates 3PG, which combines with the hydrogen ions from NADPH, to form G3P.