3.1 Food Supply, Plant Growth and Productivity Flashcards
(43 cards)
Define ‘Food Security’
The ability of a population to access food of sufficient quality and quantity
What are the three factors that influence food security?
- Food Quantity
- Food Quality
- Food Access
Why are their concerns around acheiving food security?
Increasing human population leads to increased demand for food production
Why must food production be sustainable?
So that it does not degrade the natural resources on which agriculture depends on
What does agricultural production depend on?
Factors that control photosynthesis and plant growth
Describe ways to maximise crop yield
- Use fertiliers
- Protect crops from pests, disease and competition
- Have growers develop new crop cultivars
Describe ways in which new crop cultivars can be better
- Increasing yield
- Higher nutritional values
- Resistance to pests and disease
- Developing physical characteristics suitable for harvesting
- Adaptions to particular environmental conditions
State the main food crops grown globally
- Cereals
- Legumes
- Root crops
Define ‘trophic level’
The position an organism occupies in a food chain/web
Explain why livestock are a better option than crops for some habitats
Livestock can survive on hilly or exposed land where crops could not
Explain why crops are a more efficient use of land than livestock
Livestock produce less food per unit area than crop plants due to loss of energy between trophic levels.
Define ‘photosynthesis’
a series of enzyme-controlled reactions by which plants trap light energy and use it to produce carbohydrates
Light energy is absorbed by photosynthetic pigments to generate _______
ATP and for photolysis
State the photosynthesis word equation
Carbon dioxide + Water –> Glucose + Oxygen
State the colours that make up white light
- Red
- Orange
- Yellow
- Green
- Blue
- Indigo
- Violet
When white light hits a plant what will happen to the different wavelengths (colours) of light
- Light is reflected
- Light absorbed
- Light is transmitted
Two sources of light having different wavelengths will tell you what about the light?
That they are different colours
Explain what a wavelength of light being reflected means
That wavelength/colour of light bounces off the object
Explain what a wavelength of light being transmitted means
That wavelength/colour of light passes through the object
Orange light is reflected by an object and zero light is transmitted. What does this tell us about the object?
It absorbs all wavelengths of light other than orange.
Describe the purpose of a photosynthetic pigement
To absorb light energy
Where are photosynthetic pigments found within a plant cell?
Chloroplast
State the three main photosynthetic pigments
- Chlorophyll a
- Chlorophyll b
- Carotenoids
Carotenoids are referred to as accessory pigments. What does this mean?
They extend the range of wavelengths absorbed and pass the energy to chlorophyll for photosynthesis
