7C Populations in Ecosystems Flashcards Preview

Biology A-level > 7C Populations in Ecosystems > Flashcards

Flashcards in 7C Populations in Ecosystems Deck (49)
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1
Q

What is a habitat?

A

The place where an organism lives

E.g. a rocky shore or a field

2
Q

What is a population?

A

All the organisms of one species in a habitat

3
Q

What is a community?

A

Populations of different species in a habitat make up a community

4
Q

What is an ecosystem?

A

A community, plus all the non-living (abiotic) conditions in the area in which it lives

Ecosystems can be small e.g. a pond, or large e.g. an entire ocean

5
Q

What are abiotic conditions?

A

The non-living features of the ecosystem

e.g. temp and availability of water

6
Q

What are biotic conditions?

A

The living features of the ecosystem

e.g. the presence of predators or food

7
Q

What is a niche?

A

The role of a species within its habitat

e.g. what it eats, where and when it feeds

8
Q

What is an adaption?

A

A feature that members of a species have that increased their chance of survival & reproduction

e.g. giraffes have long necks that help them to reach vegetation that’s up high - this increased their chances of survival when food is scarce

9
Q

What are the two types of niche a species can have?

A

Biotic interactions - e.g. the organism eats, and those it’s eaten by

Abiotic interactions - e.g. the oxygen an organism breathes in, and the CO2 it breathes out

10
Q

How many species can have the same niche?

A

A niche can only be occupied by one species

Every species has its own unique niche

11
Q

Why can two species look like they have the same niche?

A

They may both be eaten by the same species but they’ll be slight differences between them - ie variations in what they eat

12
Q

What happens if two species try to occupy the same niche?

A

They will compete with each other

One species will be more successful than the other until only one species is left

13
Q

Give two example of niches

A
  • The common pipistrelle bat

- Soprano pipistrelle bat

14
Q

What is the difference in the niches of the come on pipistrelle bat and the soprano pipistrelle bat?

A

Common pipi lives in Britain on farmland, open woodland, hedgerows & urban areas - feeds by flying & catching insects using echolocation at freq 45kHz

Soprano pipi lives in Britain woodland areas, close to lakes or rivers - feeds by flying & catching insects using echolocation at freq 55kHz

15
Q

Do organisms adapt to biotic or abiotic conditions?

A

Both

16
Q

Why do organisms adapt?

A

It increases the organisms chance of survival & reproduction

17
Q

What types of adaptions can organisms make?

A
  • Physiological (processes inside their body)
  • Behavioural (the way an organism acts)
  • Anatomical (structural features)
18
Q

Why are organisms that have adapted more likely to survive?

A

Their adaptions make them more likely to survive, reproduce and pass on the alleles for their adaptions become more in the population

19
Q

What is succesion?

A

It is the process in which an ecosystem changes over time

20
Q

What is meant by the phrase of “ecosystems are dynamic”?

A

They’re constantly changing - through succession

21
Q

How does succession affect the biotic & abiotic factors of the environment?

A

The biotic conditions change as the abiotic conditions change

22
Q

What are the two types of succession?

A
  • Primary succession

- Secondary succession

23
Q

What is primary succession?

A

Happens on land that’s been newly formed or exposed

e.g. where a volcano has erupted to form new rock surface/where sea level has dropped exposing new area of land –> no soil/organic material to start with (e.g. just bare rock)

24
Q

What is secondary succession?

A

Happens on land that’s been cleared of all the plants, but where soil remains

e.g. after a forest fire or where a forest has been cut down by humans

25
Q

When & how does primary succession start?

A

It starts when species colonise a new land surface

Seeds & spores are blown by the wind % begin to grow

26
Q

What is a pioneer species?

A

The first species to colonise an area

27
Q

What are the abiotic conditions like in primary succesion and how do species survive in this?

A

They are hostile (harsh) e.g. no soil to retain water

Only pioneer species grow as they’re specially adapted to cope with harsh conditions e.g. marram grass can grow on sand dunes near the sea as it has deep roots to get water & can tolerate the salty environment

28
Q

How does the poineer species affect the abiotic conditions in primary sucession?

A

The poineer species change the abiotic conditions

They die & microorganisms decompose the dead organic material (humus) –> this forms basic soil

29
Q

How do pioneer species make conditions less hostile (go through the process)?

A

They die and decompose into soil - this changes the abiotic conditions

Basic soil helps retain water, new organisms can move in & grow –> these die & decompose, adding more organic material, making soil deeper & richer in minerals

Means larger plants like shrubs can start to grow in the deeper soil, which retains even more water

30
Q

How do significant changes in abiotic conditions affect the species that live there?

A

New species may change the environment so it becomes less suitable for the previous species

e.g. sand sedge stabilises sand through the growth of rhizomes (underground stems) –> this makes the conditions less suitable for marram grass, which needs constant reburial by sand to frow healthily

31
Q

How do niches affect ecosystems?

A

Every species is adapted to use an ecosystem in a way no other species can

e.g. giant anteaters can break into any nests & reach ants - they have claws to rip up the nest, long sticky tongue that can move rapidly in & out of it’s mouth to pick up ants

32
Q

What conditions do animals adapt to in an environment?

A

The abiotic (eg how much water is available) conditions

The biotic (eg what predators there are) conditions

33
Q

What is population size?

A

Total number of organisms of one species in a habitat

34
Q

What is the carrying capacity?

A

Maximum stable population size of a species that an ecosystem can support

35
Q

What factors affect the carrying capacity for a species?

A
  • Biotic

- Abiotic

36
Q

What conditions do animals have to adapt to?

A
  • Biotic conditions (e.g. how much water is availble)

- Abiotic conditiond (e.g. what predators there are)

37
Q

Give 3 examples of animals adapting to abiotic conditions

A
  • Otters have webbed paws
  • Seals have a thick layer of blubber
  • Hedgehogs hibernate
38
Q

How are otters webbed paws an abiotic adaption?

A

They mean they can both walk & swim effectively

This increases their chance of survival becuase htey can live & hunt both on land & in water

39
Q

How are seaks having a thick layer of blubber an abiotic adaption?

A

This helps them to keep warmin the coldest seas

Increases their chance of survival because they can live in places where food is plentiful

40
Q

How is hedgehogs hibernating an abiotic adaption?

A

They lower their rate of metabolism over winter

This increases their chance of survival becuase they can conserve energy during the coldest months

41
Q

Give 3 examples of animals adapting to biotic conditions

A
  • Sea otters using rocks to open shellfish & clams
  • Male frogs produce mating calls to attract females
  • Some bacteria produce antibodies
42
Q

How is sea otters using rocks to open shellfish & clams biotic adaptions?

A

This increases their chance of survival because it gives them acess to another source of food

43
Q

How is male frogs using mating calls a biotic adaption?

A

They use the mating calls to attract women

This makes sure they attract a mate of the same species

This increases their chance of reproduction by making successful mating more likely

44
Q

How is some bacteria producing antibodies a biotic adaption?

A

These antibodies kill other species of bacteria in the same area

This increases their chance of survival because there’s less competetion for resources

45
Q

How is secondary succession different from primary succession?

A

It happens in the same way as primary succession, but because there’s already a soil layer, succession starts at a later stage

Pioneer species in secondary succession are larger plants e.g. shrubs

46
Q

What is the final stage of succession called?

A

The climax community

47
Q

What is the climax community?

A

They’re the final species that arrive

The ecosystem is supporting is supporting the largest & most complex community of plants & animals it can - it won’t change much more, it’s in a steady state

48
Q

What decides what makes the climax community?

A

It depends on what the climate is like in the ecosystem

The climax community for a particular climate is called its climatic climax

49
Q

Give some examples of how the climate will affect the climatic climax species?

A

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