Ecology
Communities
Communities:
- A population is the total number of all the organisms of the same Interdependence
species or the same group species that live in a geographical area. E.g. Abiotic and biotic factors
The human population is the total number of humans alive, and the
Adaptations
geographical area is the earth.
- A community is a group of two or more populations of different Extreme environments
species that live at the same time in the same geographical area. Levels of organisation
- Competition is the contest between organisms in a community. There
Producers, consumers and
are two types:
o Interspecific competition is between different species in the decomposers
community The carbon cycle
o Intraspecific competition is between organisms of the same The water cycle
species.
- Organisms compete over things such as light, food, warmth, mates etc. Decomposition
Impact of environmental change
Interdependence:
- Interdependence means that all the species that live in a community on distribution of organisms
depend upon each other. E.g. In a marine ecosystem sharks depend upon Biodiversity
seals and smaller fish for food.
Waste management
- A stable community is one in which there is much interdependence.
That is, all the species are in balance with each other. There are an Land use
appropriate number of predators and prey. deforestation
- As numbers of prey increase, so do the number of predators. global warming
- As the numbers of predators increase, the number of preys decrease
as they are being eaten. Eventually the reduced number of preys maintaining biodiversity
means that the number of predators will fall because there is not trophic levels
enough food. This is called the predator – prey cycle. food security
- While the numbers of predators and prey cycle naturally, interdependence means that they will almost
biotechnology
always remain within a stable number.
Abiotic and Biotic Factors:
- Abiotic Factors are the non-living parts of the environment.
- Examples of abiotic factors are, light intensity, water, pH of soil, mineral content, wind, carbon dioxide.
- Biotic Factors are those that are living or related to living organisms.
- Examples of biotic factors are, amount of food available, predators, diseases, other species.
- Invasive species is another biotic factor they are an organism that is not native and causes negative
effects.
Adaptations:
- Adaptations can be structural, behavioural or physiological.
- Structural adaptations are the physical features that allow an organism to compete. E.g. the sharpness
of a tiger’s teeth. Some animals might mimic the adaptations of others.
- Behavioural adaptations explain how specific behaviours benefit an organism. For example, dancing to
attract a mate
- Physiological / Functional adaptations are processes that organisms complete to help them survive. E.g.
venom
1
, Extreme Environments:
- An extreme environment is one that is challenging for most organisms to live within. These may be highly
acidic or alkaline, hot or cold, they may not have much oxygen or water of the ocean.
- The artic is very cold meaning animals and plants must adapt e.g. polar bears have a small head and ears
to prevent heat loss, and they have a thick layer of fat under their fur.
- A Deep-sea hydrothermal vent is a small gap of fissure on the bottom of the ocean, they are under
extreme pressure and there is no light, but some bacteria have evolved to feed on the chemicals released
by the vents.
- An organism that lives in an extreme environment is called an extremophile
Levels of Organisation:
- An ecosystem is a community of living organisms in their environment.
- A community is a group of two or more populations of different species living at the same time in the
same place.
- A population is the total number of organisms of the same species or similar species that live in the
same place.
- Sampling is a process by which scientists look at a part of a habitat and draw conclusions about the
whole of it. For example, the amount of a species.
- Quadrats are used in many forms of sampling. A quadrat is simply a square of wire or wood frame that
is placed on the ground and the organisms that are within it are recorded.
- Random Sampling is where you place the quadrat at random places in the set area and record the
amount and multiply them to find the total estimated amount in the area. Obviously, the more samples
you do the more accurate the data will be.
- Systematic Sampling is where you place the quadrat at set places for example 2 metres apart.
Producers, Consumers and Decomposers:
- There are three ways in which organisms obtain the energy store they need to live. They can produce
the energy they need. They can consume other living organisms that have already produced this energy
sore. OR they can obtain it from the bodies of dead organisms.
- Anything that photosynthesizes is a producer. It can ‘produce’ its own energy from the sun through
photosynthesis.
- Any organism that obtains its energy by eating another is a consumer. One group of consumers are
herbivores that just eat plants (the producer) e.g. Sheep and rabbits. The second group of consumers are
carnivores; these are any animals that eat meat. Omnivores eat both meat and plants.
- Only 10% of the energy in the plant or animal eaten reaches the consumer that eats it.
- A decomposer is any organism that breaks down the remains of a dead organism. This breakdown is
called decomposition or rotting. Bacteria and fungi are both decomposers.
- Fungi break down organisms by releasing digestive enzymes onto the material. Shortly after they will
absorb the nutrients from the broken-down cells by diffusion.
- If decay occurs in anaerobic conditions, methane gas is produced.
The Carbon Cycle:
- Carbon is the key element for all known life.
- The complex molecules that make up all life are made when carbon chemically bonds with other
elements, especially oxygen, nitrogen and hydrogen.
- The carbon cycle can be simplified into 4 equations:
o Photosynthesis
§ Carbon dioxide + Water à Glucose + Oxygen
2
Communities
Communities:
- A population is the total number of all the organisms of the same Interdependence
species or the same group species that live in a geographical area. E.g. Abiotic and biotic factors
The human population is the total number of humans alive, and the
Adaptations
geographical area is the earth.
- A community is a group of two or more populations of different Extreme environments
species that live at the same time in the same geographical area. Levels of organisation
- Competition is the contest between organisms in a community. There
Producers, consumers and
are two types:
o Interspecific competition is between different species in the decomposers
community The carbon cycle
o Intraspecific competition is between organisms of the same The water cycle
species.
- Organisms compete over things such as light, food, warmth, mates etc. Decomposition
Impact of environmental change
Interdependence:
- Interdependence means that all the species that live in a community on distribution of organisms
depend upon each other. E.g. In a marine ecosystem sharks depend upon Biodiversity
seals and smaller fish for food.
Waste management
- A stable community is one in which there is much interdependence.
That is, all the species are in balance with each other. There are an Land use
appropriate number of predators and prey. deforestation
- As numbers of prey increase, so do the number of predators. global warming
- As the numbers of predators increase, the number of preys decrease
as they are being eaten. Eventually the reduced number of preys maintaining biodiversity
means that the number of predators will fall because there is not trophic levels
enough food. This is called the predator – prey cycle. food security
- While the numbers of predators and prey cycle naturally, interdependence means that they will almost
biotechnology
always remain within a stable number.
Abiotic and Biotic Factors:
- Abiotic Factors are the non-living parts of the environment.
- Examples of abiotic factors are, light intensity, water, pH of soil, mineral content, wind, carbon dioxide.
- Biotic Factors are those that are living or related to living organisms.
- Examples of biotic factors are, amount of food available, predators, diseases, other species.
- Invasive species is another biotic factor they are an organism that is not native and causes negative
effects.
Adaptations:
- Adaptations can be structural, behavioural or physiological.
- Structural adaptations are the physical features that allow an organism to compete. E.g. the sharpness
of a tiger’s teeth. Some animals might mimic the adaptations of others.
- Behavioural adaptations explain how specific behaviours benefit an organism. For example, dancing to
attract a mate
- Physiological / Functional adaptations are processes that organisms complete to help them survive. E.g.
venom
1
, Extreme Environments:
- An extreme environment is one that is challenging for most organisms to live within. These may be highly
acidic or alkaline, hot or cold, they may not have much oxygen or water of the ocean.
- The artic is very cold meaning animals and plants must adapt e.g. polar bears have a small head and ears
to prevent heat loss, and they have a thick layer of fat under their fur.
- A Deep-sea hydrothermal vent is a small gap of fissure on the bottom of the ocean, they are under
extreme pressure and there is no light, but some bacteria have evolved to feed on the chemicals released
by the vents.
- An organism that lives in an extreme environment is called an extremophile
Levels of Organisation:
- An ecosystem is a community of living organisms in their environment.
- A community is a group of two or more populations of different species living at the same time in the
same place.
- A population is the total number of organisms of the same species or similar species that live in the
same place.
- Sampling is a process by which scientists look at a part of a habitat and draw conclusions about the
whole of it. For example, the amount of a species.
- Quadrats are used in many forms of sampling. A quadrat is simply a square of wire or wood frame that
is placed on the ground and the organisms that are within it are recorded.
- Random Sampling is where you place the quadrat at random places in the set area and record the
amount and multiply them to find the total estimated amount in the area. Obviously, the more samples
you do the more accurate the data will be.
- Systematic Sampling is where you place the quadrat at set places for example 2 metres apart.
Producers, Consumers and Decomposers:
- There are three ways in which organisms obtain the energy store they need to live. They can produce
the energy they need. They can consume other living organisms that have already produced this energy
sore. OR they can obtain it from the bodies of dead organisms.
- Anything that photosynthesizes is a producer. It can ‘produce’ its own energy from the sun through
photosynthesis.
- Any organism that obtains its energy by eating another is a consumer. One group of consumers are
herbivores that just eat plants (the producer) e.g. Sheep and rabbits. The second group of consumers are
carnivores; these are any animals that eat meat. Omnivores eat both meat and plants.
- Only 10% of the energy in the plant or animal eaten reaches the consumer that eats it.
- A decomposer is any organism that breaks down the remains of a dead organism. This breakdown is
called decomposition or rotting. Bacteria and fungi are both decomposers.
- Fungi break down organisms by releasing digestive enzymes onto the material. Shortly after they will
absorb the nutrients from the broken-down cells by diffusion.
- If decay occurs in anaerobic conditions, methane gas is produced.
The Carbon Cycle:
- Carbon is the key element for all known life.
- The complex molecules that make up all life are made when carbon chemically bonds with other
elements, especially oxygen, nitrogen and hydrogen.
- The carbon cycle can be simplified into 4 equations:
o Photosynthesis
§ Carbon dioxide + Water à Glucose + Oxygen
2
