Unit 3 Food Supply, Plant Growth and Productivity Flashcards
(36 cards)
What is food security?
The ability to access food that is of adequate quality and quantity to avoid hunger and malnutrition.
Why is the demand for food production increasing?
Increasing human population size.
What is sustainable food production?
Food production that does not degrade resources.
Why is it important for food production to be sustainable?
As the human population increases we need to be able to produce more food in the same area.
Give 5 factors that can lead to an increase in food production
- Breeding higher yielding cultivars
- Use of fertiliser
- Protecting crops from pests
- Protecting crops from diseases.
- Reducing competition from other plants.
What process is all food production ultimately dependent on?
Photosynthesis
Give 4 examples of commercially important plant crops.
- Cereals
- Potato
- Roots
- Legumes (peas/beans)
Give 5 features plant breeder may be trying to improve in a new breed.
- Higher nutritional values.
- Resistance to pests.
- Resistance to disease.
- Physical characteristics suited to rearing and harvesting.
- Physical characteristics that increase chances of thriving in a particular environmental condition.
Why do livestock produce less food per unit area than crop plants?
Energy is lost between trophic levels.
Why will there always be a place for livestock production even as the human population grows?
Livestock production is often possible in habitats unsuitable for growing crops.
What can happen to light that hits leaf?
It can be absorbed, transmitted or reflected.
What absorbs light in a leaf?
Photosynthetic pigments
What is the light absorbed by a pigment used for?
- Photolysis
2. Generation of ATP
Why do plants have more than one pigment?
Each pigment absorbs a different range of wavelengths of light.
What are the 2 main pigments in green plants?
Chlorophyll a and chlorophyll b.
What colours of light do chlorophyll a and b mainly absorb?
Red and blue
Why do green plants appear green?
They are reflecting green light
What is the function of carotenoids?
Carotenoids extend the range of wavelengths of light absorbed and pass the energy to chlorophyll for photosynthesis.
What does an absorption spectrum show?
The quantity of light absorbed by particular pigment at each wavelength.
What does an action spectrum show?
The rate of photosynthesis at each wavelength of light.
What happens in a pigment molecule (like chlorophyll) when light is absorbed?
Electrons in the pigment become excited.
During photosynthesis what happens to excited electrons in pigments?
Excited electron get passed through the electron transport chain releasing energy to generate ATP by ATP synthase.
What enzyme produces ATP from ADP and Pi?
ATP synthase.
Energy from absorbed light is used to generate ATP. What else is this absorbed light used for?
Photolysis
