# Biology A2 Equations

## Population Growth

Population Growth = (births + immigration) - (deaths + emigration)

Percentage Population Growth Rate in a given time period =

(population change during the period / population at the start of the period) x 100

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## Mark-Release-Recapture

Estimated Population Size =

(total number of individuals in the first sample x total number of individuals in the second sample) / the number of individuals recaptured in the second sample

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## Synthesis of ATP

ATP + H2O = ADP + Pi + energy

adenosine triphosphate + water = adenosine diphosphate + inorganic phosphate + energy

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## Birth Rate and Death Rate

Birth Rate =

(number of births per year / total population in the same year) x 100

Death Rate =

(number of deaths per year / total population in the same year) x 100

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## Photosynthesis

6CO2 + 6H2O = C6H12O6 + 6O2

6 carbon dioxide + 6 water = glucose + 6 oxygen

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## Photolysis

2H20 = 4H+ + 4e- + O2

2 molecules of water = 4 protons + 4 electrons + oxygen

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## Production of Ethanol (plants/microorganisms)

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pyruvate + NAD + CoA = acetyl CoA + reduced NAD + CO2

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## Efficiency of Energy Transfers

Energy = (energy available after the transfer / energy available before transfer) x 100

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## Hardy-Weinburg Principle

p² + 2pq + q² = 1.0

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