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Title: Population Growth
Description: AQA A level Biology looking at population growth, how humans affect population growth as well as the affects of birth rate and death rate.
Description: AQA A level Biology looking at population growth, how humans affect population growth as well as the affects of birth rate and death rate.
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Population growth
Population:- a group of animals or plants of the same species living in the same habitat
...
Animals:- birds
Plants:- grass
Snails
bushes (blackberry)
Squirrels
trees
Grass hoppers
Caterpillars
Animals and plants live together in populations as plants can provide habitats as well as a food
source
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Furthermore with a variety of animals there is more food sources created without losing a type of
specie by too much competition
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A period of slow growth
2
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A period where the population growth decline
If you put a single algal cell, capable of asexual reproduction into a newly created pond the limiting
factors would be a period of slow growth which would occur from a lack of minerals and vitamins in
the water
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Limiting factors:- factors which can limit the growth of a population
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How do humans affect population growth?
Human population has resulted in the deforestation, reduction in fish stocks and the decline in dairy
farms due to super farming in America
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This has caused a reduction the variety of species as forests have
many different levels for animals to build habitats, as well as a reduction in the variety of plants as
usually only one specific plant is needed
...
Over fishing has resulted in many areas being
deprived for other animals reliant on fish as their main food source
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Furthermore a large field could produce more food that can be used
directly, rather than feeding cows
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The development of agriculture
2
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Birth rate:- birth rate is affected by many other factors including economic conditions
countries with lower income tend to have more children due to the inability to afford
protection
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Moreover social standing effects how many children people have as it can sometimes be
seen as a status of wealth
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Political factors are also involved as china have a law of only being allowed 1 child each
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Death rate:- death rate is many affected by age, expectancy age at birth, food supply,
medical care, facilities/development of country, natural disasters and war
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Migration:Immigration:- where individuals join a population from outside
Emigration:- where individuals leave a population
Stable population:- where the birth rate and death rate are in balance and so there is no
increase or decrease in the population size
Increasing population:- where there is a high birth rate, giving a wider base to the
population pyramid and fewer older people, narrowing the apex to the pyramid
...
Decreasing population:-where there is lower birth rate than death rate leading to more
elderly people
...
Title: Population Growth
Description: AQA A level Biology looking at population growth, how humans affect population growth as well as the affects of birth rate and death rate.
Description: AQA A level Biology looking at population growth, how humans affect population growth as well as the affects of birth rate and death rate.