188.8.131.52 Some global
2.4 Soil & soil
2.4.1 Rock cycle.
184.108.40.206 The rock cycle is the
physical and chemical
processes that change
Earth's rocks into
another type of rock.
220.127.116.11 Heat, pressure, and stress turn sedimentary rock into
metamorphic rock. Then that rock can take two
different routes 1: It can be weathered or 2: it can turn
into magma at extreme heat. That magma then cools
into igneous rock and is then weathered back down
into sedimentary rock.
2.4.3 chemical and
18.104.22.168 Every rock or mineral has a different chemical
and physical composition. Some are maluable,
some ductile, and others harder or stronger.
For example: Copper is ductile and can be
stretched into wire.
22.214.171.124 Soil is very easy to erode and
displace. With this property if soil
gets wet it can wet and cause major
3 The living world
3.1 Ecosystem structure
3.1.1 At the moment humans are the supieor
population of organisms. There are many
communities on earth
126.96.36.199 A community is a
bunch of different
species living in a
3.1.2 Key stone species
188.8.131.52 Keystone species are species whose roles
have a large effect on the types and
abundance of other species in an
ecosystem. E.X. American Alligator keeps
the fish population in check. Without
them the fish pop. will become
184.108.40.206 Species diversity is the amount
of species a community holds.
This is important because if one
species goes extinct it could
ruin the whole ecosystem and
3.1.3 Ecological niche.
220.127.116.11 This is a species way of life in a
community and includes everything
that affects its survival and
reproduction, such as how much water
and sunlight it needs, how much space
it requires, what it feeds on, what
feeds on it, and the tempuratures and
other conditions it can tolerate.
3.1.4 Major terrestrial and
18.104.22.168 Some major terrestrial biomes are
tropical rainforest, temperate
deciduous forest, evergreen
coniferous forest, arctic tundra, cold
desert. chaparral, temperate
grassland, temperate desert,
savanna, and tropical desert. Some
aquatic biomes are fresh and salt
3.2 Energy flow
3.2.1 The flow of energy
through a food web.
22.214.171.124 Plants absorb chemical nutrients and the suns rays for
energy through photosynthesis, the consumers eat the
nutrient rich plants to gain energy themselves, once
the consumers die decomposers break down the animal
carcus to return nutrients to the ground and
3.2.2 Ecosystem pyramids.
126.96.36.199 The more trophic levels there
are in a food chain or web,
the greater is the cumulative
loss of usable chemical
energy as it flows through
the trophic levels.
3.3 Ecosystem diversity
3.3.1 The variety of terrestrial
and aquatic ecosystems
found in an area or on the
188.8.131.52 Each of these systems is a
storehouse of genetic and
3.4 Natural ecosystem change
3.4.1 Climate shifts
184.108.40.206 Climate has been changing over
thousands of years. The most recent
change is the warming of the
3.4.2 Species movements
220.127.116.11 many species move to
different places, mainly
seasonally. This is called
3.5 Natural biochemical cycles.
3.5.1 Carbon cycle.
18.104.22.168 Terrestrial producers remove CO2
from the atmosphere, then
decomposers carry out aerobic
resperation. This breaks down
glucose and other complex
compounds into CO2
3.5.2 Nitrogen cycle.
22.214.171.124 Nitrogen in the atmosphere becomes ammonia in the soil
through electrical storms, Then it either goes directly to
plants or becomes a nitrate in the soil. Then the plants uptake
the nitrogen, the nitrogen is then going into animals. After
the animals die decomposers turn the nitrogen back into
3.5.3 Phosphorus cycle.
126.96.36.199 Phophates start in the deep ocean, do the the movement to tectonic
plates they find their way to the rocks on shore. Erosion then dissolves
the phosphates back into the water which will either go into ocean food
webs or get absorbed by plants then animals then released by
3.5.4 Sulfer cycle.
188.8.131.52 Sulfer starts int he rocks and then is either uptaken by plants or
dissolves in the ocean. When it dissolves into the ocean bacteria
creates a by-product called dimethyl sulfide and is released into
the atmosphere. Then sulfur is deposited by acid rain.
3.5.5 water cycle.
184.108.40.206 Water in oceans, surface, lakes, runoff,
rivers, and plants evaporates into the
atmosphere. The water then codinsates
in the atmosphere and falls back to earth
220.127.116.11 Matter cant be
4.1 population biology concepts.
4.1.1 Population ecology
18.104.22.168 Every organism has a population of its species with some more
than others. E.X. the human population is about 8 million.
4.1.2 Carrying capacity.
22.214.171.124 The carrying capacity is the
maximum amount of species
an ecosystem can sustain.
4.1.3 Reproductive strategy.
126.96.36.199 If there are more births than deaths during a given
period of time, the Earths population increases,
and when the opposite is true, it decreases.
188.8.131.52 The only way to survive is to have a greater crude birth rate and
crude death rate to increase the population and thrive.
4.2 Human population
4.2.1 The human population is
about 8 million and is
expected to achieve about
10.8 billion in 2050.
184.108.40.206 The average fetility rate is 2.5
4.3.1 Strategy for sustainibility.
220.127.116.11 First of all the human population is over
the carrying capacity and is threatening the
sustainibility of other organisms. To try and
combat this could help countries develope.
If we can do this then the population will
shrink to a more reasonable size.
4.3.2 Case studies.
18.104.22.168 During the time between 1900 and 2012 the us
population increased from 76 million to 314
million. How did this happen? Between 1946
and 1964 the baby boom added 79 million
people to the U.S. population. In 1957 the
average TFR was 3.7 children then decresed to
2.1, but the population is still growing.
22.214.171.124 The american baby boom
added 79 million to the U.S.
population. This generation
has greatly influenced the
economy because they
make up 36% of all adults.
4.4 Impacts on population growth.
4.4.1 Hunger and disease.
126.96.36.199 People mainly in LDCs suffer from either malnutrition
or undernutrition. This increases the infant mortality
rate and the likely hood of catching a deadly disease.
4.4.2 Economic effects.
188.8.131.52 The strength of the economy can either cause death or
survival. If the economy of a country is strong then it is
able to feed its people and thrive as a community. If the
country has a poor economy then it struggles to feed its
people and causes famine and death.
4.4.3 Resource use and
184.108.40.206 With the growing population of the
human population more and more
resources are being consumed faster
than they can be replenished. This can
lead to the destruction of one or many