A group of organisms of the same species living in the same place at the same time.

All of the populations living in the same area at the same time.

All the biotic factors and all the abiotic factors that interact within an area at one time.

The place where an organism lives, e.g. a woodland habitat for badgers and oak trees.

What is meant by interdependence?

Where each species in a community depends on other species for things like food, shelter, pollination and seed dispersal, so removing one species can affect the whole community.

What is the difference between biotic and abiotic factors?

Biotic factors are living components, such as plants and animals. Abiotic factors are non-living components, such as light intensity, mineral ions and water availability.

Give an example of a small and a large ecosystem.

A small ecosystem could be a garden pond. A large ecosystem could be the whole of Antarctica.

How does a population differ from a community?

A population is a group of one species in an area, whereas a community is all the populations (all the species) living in that area at the same time.

A non-living factor within an environment, such as temperature, light intensity and water availability.

A living factor within an environment, such as competition, predation and disease.

Name three abiotic factors that can affect a community.

Any three of: temperature, light intensity, water availability, mineral availability and pH.

Name three biotic factors that can affect a community.

Competition, predation and disease.

In what two ways can abiotic and biotic factors affect a species?

They can change the population size (increase or decrease it) and change the distribution of the population (where it lives).

How can pollutants act as an abiotic factor?

The presence and levels of pollutants can change the size and distribution of populations of certain species.

Why are lichen useful indicators of air pollution?

They are very sensitive to air pollution and cannot grow if the concentration of sulfur dioxide rises above a certain level.

Where each species in a community depends on other species for things like food, shelter, pollination and seed dispersal, so a change in one population affects others.

A community where all the species and environmental factors are in balance, so that population sizes remain fairly constant.

Give three examples of interactions between organisms in a community.

Predators eating prey, herbivores eating plants, and plants being pollinated by bees.

Why can removing one species affect the whole community?

Because species depend on each other (interdependence), so a change in one population has knock-on effects on other species.

In a food web, if the earthworm population decreased, what would happen to the grass plants?

The grass plant population would increase, as there are now fewer species feeding on them.

If earthworms decreased, why would the frog and mouse populations decrease significantly?

Because earthworms are their only food source.

If earthworms decreased, why would the sparrow population only decrease slightly?

Because sparrows eat earthworms but also have another food source (caterpillars) to rely on.

When describing changes in a food web, what words should you use instead of saying a species would 'die out'?

Use decrease or increase (in the population of a species), and always give a reason for the change.

A relationship where a parasite lives in or on a host , gaining resources while the host gets no benefit and is often harmed.

A relationship between two species in a community in which both organisms benefit in some way.

The species that a parasite lives in or on, and from which the parasite gains resources.

What resources can a parasite gain from its host?

Food, shelter and a suitable location to reproduce (where offspring can feed and grow).

Give an example of a parasitic relationship.

Fleas are parasites of mammals (e.g. dogs); they feed on the host's blood but give nothing to the host in return.

How do both species benefit in the relationship between bees and flowering plants?

Bees gain nectar (food for energy) from the flowers. The flowers gain help in reproducing, as bees spread pollen between them, pollinating them.

How does parasitism differ from mutualism?

In parasitism only the parasite benefits and the host is harmed, whereas in mutualism both organisms benefit.

Why is a flea–dog relationship described as parasitism rather than mutualism?

Because only the flea benefits (by feeding on blood) while the dog (host) gains nothing and is harmed.

The range and variety of different species of organisms within a given area (e.g. within an ecosystem or on Earth).

As well as species richness, what else does biodiversity consider?

The variation within each species, including the relative abundance (population size) of each species present.

What would an area of high biodiversity look like?

It would have lots of different species, showing a lot of variation, that are all evenly distributed across the area.

Give three things that different species depend on each other for.

Food, shelter (e.g. birds nesting in trees), and maintenance of the physical environment.

How do tree roots help maintain the physical environment?

They provide stability for soils so they are not washed away, which in turn provides a stable habitat for other plant species.

How does high biodiversity help keep an ecosystem stable?

It reduces the dependence of one species on another for food, shelter and maintenance of the physical environment.

Why are populations with high diversity more resilient?

They are more likely to cope with sudden environmental impacts or diseases.

If the mouse population in a food web was wiped out, why might the fox and hawk populations not also be wiped out?

Because mice are not their only food source; foxes can still depend on rabbits and frogs, and hawks on frogs and sparrows.

A square frame (e.g. 0.25 m² or 1 m²) placed on the ground to mark off an area being sampled, used to record the organisms within it.

GCSEScienceEdexcelCombined ScienceBiologyFlashcardsEcosystems & Material CyclesThe Organism in the Environment

The Organism in the Environment (Edexcel GCSE Combined Science: Biology): Flashcards

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Cards in this collection (61)

Population
A group of organisms of the same species living in the same place at the same time.
Community
All of the populations living in the same area at the same time.
Ecosystem
All the biotic factors and all the abiotic factors that interact within an area at one time.
What is a habitat?
The place where an organism lives, e.g. a woodland habitat for badgers and oak trees.
What is meant by interdependence?
Where each species in a community depends on other species for things like food, shelter, pollination and seed dispersal, so removing one species can affect the whole community.
What is the difference between biotic and abiotic factors?
Biotic factors are living components, such as plants and animals.
Abiotic factors are non-living components, such as light intensity, mineral ions and water availability.
Give an example of a small and a large ecosystem.
A small ecosystem could be a garden pond.
A large ecosystem could be the whole of Antarctica.
How does a population differ from a community?
A population is a group of one species in an area, whereas a community is all the populations (all the species) living in that area at the same time.
A is a group of organisms of the same species living in the same place at the same time.
Population
A community includes all of the living in the same area at the same time.
populations
Abiotic factor
A non-living factor within an environment, such as temperature, light intensity and water availability.
Biotic factor
A living factor within an environment, such as competition, predation and disease.
Name three abiotic factors that can affect a community.
Any three of: temperature, light intensity, water availability, mineral availability and pH.
Name three biotic factors that can affect a community.
Competition, predation and disease.
In what two ways can abiotic and biotic factors affect a species?
They can change the population size (increase or decrease it) and change the distribution of the population (where it lives).
How can pollutants act as an abiotic factor?
The presence and levels of pollutants can change the size and distribution of populations of certain species.
Why are lichen useful indicators of air pollution?
They are very sensitive to air pollution and cannot grow if the concentration of sulfur dioxide rises above a certain level.
What does the term 'abiotic' mean?
Non-living.
In Biology, 'abiotic' means and 'biotic' means .
non-living / living
, predation and disease are all examples of biotic factors.
Competition
Interdependence
Where each species in a community depends on other species for things like food, shelter, pollination and seed dispersal, so a change in one population affects others.
Stable community
A community where all the species and environmental factors are in balance, so that population sizes remain fairly constant.
Give three examples of interactions between organisms in a community.
Predators eating prey, herbivores eating plants, and plants being pollinated by bees.
Why can removing one species affect the whole community?
Because species depend on each other (interdependence), so a change in one population has knock-on effects on other species.
In a food web, if the earthworm population decreased, what would happen to the grass plants?
The grass plant population would increase, as there are now fewer species feeding on them.
If earthworms decreased, why would the frog and mouse populations decrease significantly?
Because earthworms are their only food source.
If earthworms decreased, why would the sparrow population only decrease slightly?
Because sparrows eat earthworms but also have another food source (caterpillars) to rely on.
When describing changes in a food web, what words should you use instead of saying a species would 'die out'?
Use decrease or increase (in the population of a species), and always give a reason for the change.
A community is one where all the species and environmental factors are in balance, so population sizes remain fairly constant.
stable
A change in the population of one species can have knock-on effects for other species; this is called .
interdependence
Parasitism
A relationship where a parasite lives in or on a host, gaining resources while the host gets no benefit and is often harmed.
Mutualism
A relationship between two species in a community in which both organisms benefit in some way.
What is a host?
The species that a parasite lives in or on, and from which the parasite gains resources.
What resources can a parasite gain from its host?
Food, shelter and a suitable location to reproduce (where offspring can feed and grow).
Give an example of a parasitic relationship.
Fleas are parasites of mammals (e.g. dogs); they feed on the host's blood but give nothing to the host in return.
How do both species benefit in the relationship between bees and flowering plants?
Bees gain nectar (food for energy) from the flowers.
The flowers gain help in reproducing, as bees spread pollen between them, pollinating them.
How does parasitism differ from mutualism?
In parasitism only the parasite benefits and the host is harmed, whereas in mutualism both organisms benefit.
Why is a flea–dog relationship described as parasitism rather than mutualism?
Because only the flea benefits (by feeding on blood) while the dog (host) gains nothing and is harmed.
In a parasitic relationship the parasite benefits while the is harmed and gains nothing.
host
A relationship in which both species benefit is called .
mutualism
Biodiversity
The range and variety of different species of organisms within a given area (e.g. within an ecosystem or on Earth).
As well as species richness, what else does biodiversity consider?
The variation within each species, including the relative abundance (population size) of each species present.
What would an area of high biodiversity look like?
It would have lots of different species, showing a lot of variation, that are all evenly distributed across the area.
Give three things that different species depend on each other for.
Food, shelter (e.g. birds nesting in trees), and maintenance of the physical environment.
How do tree roots help maintain the physical environment?
They provide stability for soils so they are not washed away, which in turn provides a stable habitat for other plant species.
How does high biodiversity help keep an ecosystem stable?
It reduces the dependence of one species on another for food, shelter and maintenance of the physical environment.
Why are populations with high diversity more resilient?
They are more likely to cope with sudden environmental impacts or diseases.
If the mouse population in a food web was wiped out, why might the fox and hawk populations not also be wiped out?
Because mice are not their only food source; foxes can still depend on rabbits and frogs, and hawks on frogs and sparrows.
is the range and variety of different species of organisms within a given area.
Biodiversity
High biodiversity ensures the of ecosystems by reducing the dependence of one species on another.
stability
Quadrat
A square frame (e.g. 0.25 m² or 1 m²) placed on the ground to mark off an area being sampled, used to record the organisms within it.
Belt transect
A method where quadrats are placed at regular intervals along a measuring tape, recording the abundance of each species in each quadrat.
Why is sampling used instead of counting every organism?
In large, complex ecosystems it is impossible to find, identify and count every individual, so sampling small areas is used to estimate the distribution and abundance of species.
What is meant by the abundance of a species?
The total number of individuals of a species within a given area.
What type of organisms are quadrats useful for, and why?
Organisms that do not move around, such as plants or sessile animals like limpets, because they stay still to be found and counted.
Why must quadrats be placed randomly, and how is this done?
To avoid sampling bias. The area can be turned into a numbered grid and a random number generator used to pick the sample points.
When is a belt transect used rather than random quadrats?
When investigating how species distribution changes across an environmental gradient, e.g. changes in altitude, soil pH or light intensity.
How does a line transect differ from a belt transect?
A line transect only records which species touch the line at set distances (presence), whereas a belt transect records the abundance of each species in quadrats along the line.
Why should at least 10 quadrat readings be taken in each survey area?
To ensure the data collected is random and representative of the survey area.
A is a square frame placed on the ground to sample the organisms within it.
quadrat
Quadrats must be placed in the area to avoid sampling bias.
randomly

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