U3 KA1 Flashcards

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1
Q

What is food security?

A
  • the ability of human populations to have access to food of sufficient quality and quantity.
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2
Q

What is 1 global concern for food security?

A
  • rapidly increasing global population, and increasing demand for food production.
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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.
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4
Q

What are the limiting factors of agricultural production? (5)

A
  • soil moisture, temperature, light availability, nutrient availability, pests.
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5
Q

How can agriculture production be improved? (3)

A
  • using pesticides and fertilisers.
  • breeding higher yield cultivars.
  • crop protection.
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6
Q

What is a trophic level?

A
  • an organisms place on the food web.
  • eg. producer, primary consumer, etc.
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7
Q

Why are crops grown instead livestock?

A
  • growing crops is more efficient, as over 90% of energy is lost between trophic levels.
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8
Q

Why is livestock produced instead of crops?

A
  • livestock production is possible in areas that plants cannot grow.
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9
Q

What is photosynthesis?

A
  • the process by which green plants take energy from sunlight, converting it to sugar.
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10
Q

What is chlorophyll A?

A
  • the main pigment found in chloroplasts of plants that absorb light energy.
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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.
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12
Q

What happens to the light that is not absorbed by the plant? (2)

A
  • reflected off the leaf.
  • transmitted through the leaf.
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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.
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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.
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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.
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16
Q

What are the uses of G3P? (2)

A
  • regeneration of RuBP.
  • synthesis of glucose.
17
Q

What are the uses of glucose? (3)

A
  • used as a respiratory substance.
  • converted to starch.
  • passed to biosynthetic pathways to form DNA, protein and fat.
18
Q

Why does the concentration of RuBP increase, when Co2 concentration decreases? (2)

A
  • there is less Co2 to combine with RuBP.
  • 3PG is still regenerated to RuBP so it increases.
19
Q

Why is algae immobilised into gel beads?

A
  • is allows the algae and incubator to be separated easily.