GCSE Biology: B16 - Adaptations, interdependence, and competition

What is a habitat?

a habitat is the environment in which an organism lives

Name an example of a habitat

E.g. one of the habitats of elephants is grasslands. Thousands of elephants live in this habitat.

What is a population?

a population is the total number of organisms of the same species living in the same geographical area

What sort of species do habitats contain?

Habitats can contain various species of animals and plants, as well as many species of insects, bacteria, and fungi.

What is a community?

a community is the populations of all the different species that live in the same habitat

What does a community contain?

A community contains all the living organisms in an environment. Scientists call this the biotic part of the environment.

What does biotic mean?

Biotic means living

What is meant by the abiotic parts of an environment?

The non-living parts of an environment are called the abiotic parts.

What does abiotic mean?

Abiotic means non-living

Name some examples of the abiotic parts of an environment

The abiotic parts of an environment include:

- the amount of water

- the minerals in the soil

This means they are non-living parts of an environment.

What is an ecosystem?

an ecosystem is both the biotic and abiotic parts of an environment and how they interact

What do living organisms require?

Living organisms require a supply of materials from their surroundings. E.g. water.

As well as from their surroundings, how else do living organisms get the materials they require?

Living organisms also get materials from other living organisms.

Describe an example of how living organisms get materials from other living organisms

E.g. Zebras, giraffes, and gazelles get materials from the plants that they eat.

Name two ways in which living organisms get materials

Living organisms get materials:

- from their surroundings

- from other living organisms

Why do living organisms have to compete with each other?

- resources that living organisms require are often in short supply

- so this means organisms have to compete with each other

Resources that living organisms require are ...

Resources that living organisms require are often in short supply. This means living organisms often have to compete with each other for resources.

Describe which resources plants compete for

- plants compete with each other for light and space

- plants also compete for water and for minerals ions in the soil

Name the resources plants compete for

Plants compete for:

- light

- space

- water

- mineral ions in the soil

Name the resources that animals compete with each other for

Animals compete with each other for:

- food and water

- mating partners

- territory

Animals and plants both compete for ...

Animals and plants both compete for water.

What is interdependence?

Interdependence is where all the different species in a community depend on each other for something

Name the ways in which interdependence can be seen in a community

Interdependence:

- animals rely on other living organisms for food

- living organisms rely on each other for shelter

- plants can depend on animals

Describe how species depend on other living organisms for food

- every animal depends on other living organisms for food

- e.g. lions eat animals such as zebras and gazelles

- other animals get their food by eating plants,

- e.g. both zebras and gazelles eat grass and shrubs

Describe how species can depend on other living organisms for shelter

- some living organisms provide shelter for other living organisms

- e.g. a tree could shelter animals from the sun

Describe how within a community, plants can depend on animals

- plants can depend on animals

- e.g. many plants depend on bees to spread their pollen, or birds which can disperse pollen seeds in their faeces

How is interdependence important in an ecosystem?

- interdependence is important in an ecosystem

- because if one species is removed from the ecosystem, all of the other species will be affected

Explain the effect of a species disappearing from a community on interdependence

- if a species disappears from a community, this can affect the whole community:

- if the species that disappears is relied upon by another species, this species could become unable to survive and reproduce as well

- the species that feeds on the species now unable to survive and reproduce as well could run out of food, and their populations would fall

Describe an example of the effect of a species disappearing from a community on interdependence

E.g. - if bees disappeared from a community, lots of

different plants would not get pollinated and

would be unable to reproduce

- animals which feed on these plants could then run

out of food, and their populations would fall

What is a stable community?

a stable community is a community where the populations of the different species remain fairly constant

Describe the organisms in a stable community

In a stable community, the populations of organisms are in balance with each other and with the abiotic resources, such water.

Order the levels of organisation in an ecosystem

Habitat, Population, Community, Ecosystem, Biosphere

What are biotic factors?

biotic factors are living factors in an ecosystem

Name the biotic factors in an ecosystem

Biotic factors in an ecosystem:

- availability of food

- arrival of a new predator

- competition between species

- new pathogens

What does it mean if a species competes intraspecifically?

Intraspecifically means there is competition between members of the same species.

E.g. a snake competes intraspecifically with other snakes

Describe how the availability of food is a biotic factor in an ecoystem

Availability of food:

- all animals eat other living organisms

- e.g. lions eat other animals, zebras eat plants

- however, all sources of food, whether animals or plants, are a biotic factor

- if the availability of food falls, the number of organisms in that community will also fall

What is the effect of a fall in availability of food?

When the availability of food falls, the number of organisms in the community also falls.

Describe how the arrival of a new predator is a biotic factor in an ecosystem

Arrival of a new predator:

- a new predator can cause the population of a prey species to fall

- a new predator can also affect existing predators if they are competing for the same prey

Describe how competition between species is a biotic factor in an ecosystem

- if a species is outcompeted, then its population can fall so much that numbers are no longer sufficient to breed and the species may become extinct.

Describe how new pathogens is a biotic factor in an ecosystem

- if an infectious disease emerges and then spreads, this new pathogen can wipe out an entire population of a species

What type of factor in an ecosystem are parasites?

Parasites are a biotic factor in an ecosystem.

What is are abiotic factors?

abiotic factors are non-living factors in an ecosystem

Name the abiotic factors of an ecosystem

Abiotic factors in an ecosystem:

- light intensity

- temperature

- water

- pH and mineral content of soil

- wind intensity and direction

- carbon dioxide

- oxygen

What do plants need for photosynthesis?

All plants need light to carry out photosynthesis

Describe how light intensity is an abiotic factor in an ecosytem

Light intensity:

- all plants need light to carry out photosynthesis

- so if light intensity is too low, the rate of photosynthesis falls and plants will grow more slowly

- this can have a major impact on a community, because if plants grow more slowly, animals which feed on plants may not have enough food

What can happen to plants if light intensity is too low?

If light intensity is too low, the rate of photosynthesis falls and plants will grow more slowly. This can cause animals that feed on plants to not have enough food.

Describe how temperature is an abiotic factor in an ecosystem

- if the temperature of an environment changes, the distribution of species can change

- for example, animals could migrate and plant species may simply disappear from that area

What do both plants and animals need to survive?

Both plants and animals need water to survive.

Describe how water is an abiotic factor in an ecosystem

- water is a major abiotic factor as both plants and animals need water to survive

- many species are adapted to deal with low levels of water

Plants can not grow on soil which is .......

Plants can not grow on soil which is too acidic or too alkaline.

Describe how the pH and mineral content of soil is an abiotic factor in an ecosystem

- the pH and mineral content of the soil is an important abiotic factor as many plants can not grow on soil which is too acidic or too alkaline

- plants also need certain minerals in the soil, such as nitrate, which is used to make amino acids for proteins

Name an example of a mineral that plants need in the soil

Plants need nitrate in the soil, as well as other certain minerals.

What is the role of the mineral nitrate in the soil for plants?

Nitrate is used to make amino acids for proteins in plants.

Describe how wind intensity and direction is an abiotic factor in an ecosystem

- wind intensity and direction is another abiotic factor that can affect plants

- for example, strong winds blowing inland from the sea can cause plants to lose water

- this means plants growing in sand dunes are often adapted to reduce water loss

What are plants in sand dunes often adapted for?

Plants in sand dunes are often adapted to reduce water loss, as strong winds blowing inland from the sea can cause them to lose water.

Describe how carbon dioxide is an abiotic factor in an ecosystem

- carbon dioxide is needed for plants to photosynthesise

- if carbon dioxide levels fall, the rate of photosynthesis can also decrease

Why may the rate of photosynthesis decrease?

The rate of photosynthesis can decrease if carbon dioxide levels fall.

What do plants need to photosynthesise?

To photosynthesise, plants need:

- carbon dioxide

- water

- light

What is oxygen needed for?

Oxygen is needed for aerobic respiration.

Describe how oxygen is an abiotic factor in an ecoystem

- oxygen is needed for aerobic respiration

- the level of oxygen in the air stays fairly constant, but the level of dissolved oxygen in water can fall

- this can be harmful to aquatic organisms such as fish

Why might dissolved oxygen levels in water fall?

Dissolved oxygen levels in water can fall, for example on hot days. This can be harmful to aquatic organisms.

If dissolved oxygen levels in water fall, ...

If dissolved oxygen levels in water fall, this can be harmful to aquatic organisms.

What may an exam question on adaptations look like?

In the exam, you could be given information on any living organism, and asked to suggest how it is adapted to its environment. You do not need to learn the adaptations of specific organisms, but you do need to know some examples of adaptations.

What are structural adaptations?

structural adaptions are adaptations of body shape or body structure

Name the structural adaptations an organism that lives in the hot and dry conditions of a desert may have

If an organism lives in the hot and dry conditions of a desert, it may have the following structural adaptations:

- a store of fat

- a thick coat on its body surface

- leathery mouth

- long eyelashes

- closed nostrils

- wide feet

Why may an organism living in the hot and dry conditions of a desert have a store of fat as a structural adaptation?

- a store of fat may be an adaptation of an organism due to the hot and dry conditions of the habitat is lives in

- fat is a thermal insulator, so if an organism stores fat in a certain place, this allows heat loss from the other parts of the organism's body, reducing water loss from sweating

- the store of fat can also be used to produce water using metabolic reactions

Why may an organism living in the hot and dry conditions of a desert have a thick coat as a structural adaptation?

- an organism living in hot and dry desert conditions may have a thick coat on the upper surface of their body

- this thick coat insulates top of the organism from the heat of the sun and reduces water loss from sweating

Why could an organism living in the hot and dry conditions of a desert have a leathery mouth as a structural adaptation?

- an organism living in the hot and dry conditions of a desert may have a leathery mouth as an adaptation

- a leathery mouth enables an organism in the desert to chew desert plants which often have thorns but are a good source of water

Why may an organism that lives in hot and dry desert conditions have long eyelashes as one of its structural adaptations?

- organisms living in hot and dry desert conditions may have long eyelashes as an adaptation

- long eyelashes keep dust from the desert floor out of the organism's eyes

Why might an organism living in the hot and dry conditions of a desert have the ability to close their nostrils as a structural adaptation?

- organisms living in the desert may have a structural adaptation which means they can close their nostrils

- if an organism in the desert closes its nostrils, this keeps dust out of its nose

Why may an organism living in the hot and dry conditions of a desert have wide feet as a structural adaptation?

- an organism living in a hot and dry desert could have wide feet as a structural adaptation

- wide feet prevents the organism from sinking into the sand

What are functional adaptations?

functional adaptations are adaptations to the body functions of an organism

Name the functional adaptations an organism living in the hot and dry conditions of a desert may have

If an organism is living in the hot and dry conditions of a desert, if may have the following functional adaptations:

- concentrated urine and dry faeces

- ability to tolerate very large changes in its body temperature

Why may an organism that lives in a hot and dry desert have concentrated urine and dry faeces as a functional adaptation?

- an organism living in a hot and dry desert might produce concentrated urine and dry faeces as a functional adaptation

- concentrated urine and dry faeces reduce the organism's water loss

Why may an organism that lives in a hot and dry desert habitat have the ability to tolerate very large changes in body temperature as a functional adaptation?

- an organism that lives in a desert may be able to tolerate very large changes in their body temperature as a functional adaptation

- very large changes in body temperature help an organism to cope with the intense heat of a desert

What are behavioural adaptations?

behavioural adaptations are adaptations to an animal's lifestyle or behaviour

Describe the behavioural adaptations an organism that is nocturnal may have and why these are useful to the organism

- organisms that are nocturnal are mainly active at night

- and being nocturnal is a behavioural adaptation

- the organism therefore avoids the heat of the daytime

- during the day, the organism may live in burrows underground, in order to keep cool and protected from predators

Name some examples of behavioural adaptations an organism may have

Examples of behavioural adaptations in organisms:

- being nocturnal

- living underground to keep cool and protected from predators

Name the three types of adaptations organisms can have

Structural adaptations

Functional adaptations

Behavioural adaptations

Name the structural adaptations an organism living in very cold conditions, e.g. the Arctic, may have

Structural adaptations an organism living in very cold conditions may have:

- very thick fur

- fur on the soles of its feet

- very small ears

- camouflage from its coat

How might the structural adaptation of very thick fur help an organism living in very cold conditions?

- an organism living in very cold conditions may have very thick fur

- very thick fur provides the organism insulation and reduces heat loss to the air

How might the structural adaptation of fur on the soles of the feet help an organism living in very cold conditions?

- an organism living in very cold conditions might have fur on the soles of its feet

- fur on the soles of an organism's feet reduces heat loss to the ice and snow

How could the structural adaptation of very small ears help an organism living in very cold conditions?

- an organism living in very cold conditions may have the structural adaptation of very small ears

- having very small ears reduces an organism's surface area, so reduces its heat loss

If an organism has a small surface area, ...

If an organism has a small surface area, it will have a smaller heat loss to the environment, so it will stay insulated.

If an organism has a large surface area, it will have more heat loss.

How could the structural adaptation of camouflage help an organism that lives in very cold conditions?

- an organism living in very cold conditions may have a coat that provides effective camouflage to the snowy conditions

- camouflage helps the organism to hunt its prey more easily

Name a plant well adapted to living in dry conditions

The cactus lives in the dry conditions of the desert and it is very well adapted to these conditions.

What problem do plants in dry conditions face?

Losing water through their leaves is a problem for plants that live in dry conditions. Cacti have adaptations that solve this problem.

Name the adaptations of plants, such as cacti, that live in dry conditions may have

Cacti have the following adaptations for living in the dry conditions of the desert:

- very small leaves

- having spines instead of any leaves

- extensive and shallow roots

- a stem that stores water

How does the adaptation of very small leaves help plants such as cacti live in dry conditions?

- some cacti have the adaptation very small leaves, in order to live in the dry conditions of the desert

- having very small leaves reduces the cacti's water loss

How does the adaptation of having only spines instead of any leaves help plants such as cacti live in dry conditions?

- some cacti have no leaves at all, only spines, which are an adaptation to help cacti to live in the dry conditions of the desert

- spines protect cacti from animals

Spines protect cacti ...

Spines protect cacti from animals. This adaptation allows cacti to live in the dry conditions of a desert.

How does the adaptation of extensive and shallow roots help plants such as cacti to live in the dry conditions of a desert?

- as deserts are dry and there is often little rain, cacti have the adaptation of extensive and shallow roots

- extensive and shallow roots allow cacti to catch as much water as possible after rainfall, before the water evaporates or sinks into the ground

What allows cacti to catch more rainfall in order to survive in dry conditions?

Cacti have extensive and shallow roots so they can catch as much water as possible after rainfall before it evaporates or sinks into the ground. This adaptation allows plants such as cacti to live in the dry conditions of a desert.

How does the adaptation of a stem that stores water help plants such as cacti to live in the dry conditions of a desert?

- cacti can also store water in their stem

- this adaptation means cacti can survive many months without rain in the dry conditions of a desert as they store water in their stem as a reserve

What type of adaptation is hibernation in winter?

Hibernation in winter is a behavioural adaptation.

What type of adaptation is the migration of birds?

The migration of birds is a behavioural adaptation.

What type of adaptation is being nocturnal?

Being nocturnal is a behavioural adaptation.

What type of adaptation is producing very little sweat?

Producing very little sweat is a functional adaptation.

How may a leopard having the adaptation of spots on its coat help it to survive in its habitat?

- spots act as a camouflage

- so the leopard can hide from prey

What structural adaptations may a polar bear have in order to survive very cold conditions?

- very thick fur

- a thick blubber