7C Populations in Ecosystems

Question 1

What is a habitat?

Answer 1

The place where an organism lives

E.g. a rocky shore or a field

Question 2

What is a population?

Answer 2

All the organisms of one species in a habitat

Question 3

What is a community?

Answer 3

Populations of different species in a habitat make up a community

Question 4

What is an ecosystem?

Answer 4

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

Question 5

What are abiotic conditions?

Answer 5

The non-living features of the ecosystem

e.g. temp and availability of water

Question 6

What are biotic conditions?

Answer 6

The living features of the ecosystem

e.g. the presence of predators or food

Question 7

What is a niche?

Answer 7

The role of a species within its habitat

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

Question 8

What is an adaption?

Answer 8

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

Question 9

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

Answer 9

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

Question 10

How many species can have the same niche?

Answer 10

A niche can only be occupied by one species

Every species has its own unique niche

Question 11

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

Answer 11

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

Question 12

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

Answer 12

They will compete with each other

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

Question 13

Give two example of niches

Answer 13

• The common pipistrelle bat

- Soprano pipistrelle bat

Question 14

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

Answer 14

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

Question 15

Do organisms adapt to biotic or abiotic conditions?

Answer 15

Both

Question 16

Why do organisms adapt?

Answer 16

It increases the organisms chance of survival & reproduction

Question 17

What types of adaptions can organisms make?

Answer 17

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

Question 18

Why are organisms that have adapted more likely to survive?

Answer 18

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

Question 19

What is succesion?

Answer 19

It is the process in which an ecosystem changes over time

Question 20

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

Answer 20

They’re constantly changing - through succession

Question 21

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

Answer 21

The biotic conditions change as the abiotic conditions change

Question 22

What are the two types of succession?

Answer 22

• Primary succession

- Secondary succession

Question 23

What is primary succession?

Answer 23

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)

Question 24

What is secondary succession?

Answer 24

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

Question 25

When & how does primary succession start?

Answer 25

It starts when species colonise a new land surface Seeds & spores are blown by the wind % begin to grow

Question 26

What is a pioneer species?

Answer 26

The first species to colonise an area

Question 27

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

Answer 27

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

Question 28

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

Answer 28

The poineer species change the abiotic conditions They die & microorganisms decompose the dead organic material (humus) --> this forms basic soil

Question 29

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

Answer 29

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

Question 30

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

Answer 30

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

Question 31

How do niches affect ecosystems?

Answer 31

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

Question 32

What conditions do animals adapt to in an environment?

Answer 32

The abiotic (eg how much water is available) conditions The biotic (eg what predators there are) conditions

Question 33

What is population size?

Answer 33

Total number of organisms of one species in a habitat

Question 34

What is the carrying capacity?

Answer 34

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

Question 35

What factors affect the carrying capacity for a species?

Answer 35

- Biotic | - Abiotic

Question 36

What conditions do animals have to adapt to?

Answer 36

- Biotic conditions (e.g. how much water is availble) | - Abiotic conditiond (e.g. what predators there are)

Question 37

Give 3 examples of animals adapting to abiotic conditions

Answer 37

- Otters have webbed paws - Seals have a thick layer of blubber - Hedgehogs hibernate

Question 38

How are otters webbed paws an abiotic adaption?

Answer 38

They mean they can both walk & swim effectively This increases their chance of survival becuase htey can live & hunt both on land & in water

Question 39

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

Answer 39

This helps them to keep warmin the coldest seas Increases their chance of survival because they can live in places where food is plentiful

Question 40

How is hedgehogs hibernating an abiotic adaption?

Answer 40

They lower their rate of metabolism over winter This increases their chance of survival becuase they can conserve energy during the coldest months

Question 41

Give 3 examples of animals adapting to biotic conditions

Answer 41

- Sea otters using rocks to open shellfish & clams - Male frogs produce mating calls to attract females - Some bacteria produce antibodies

Question 42

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

Answer 42

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

Question 43

How is male frogs using mating calls a biotic adaption?

Answer 43

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

Question 44

How is some bacteria producing antibodies a biotic adaption?

Answer 44

These antibodies kill other species of bacteria in the same area This increases their chance of survival because there's less competetion for resources

Question 45

How is secondary succession different from primary succession?

Answer 45

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

Question 46

What is the final stage of succession called?

Answer 46

The climax community

Question 47

What is the climax community?

Answer 47

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

Question 48

What decides what makes the climax community?

Answer 48

It depends on what the climate is like in the ecosystem The climax community for a particular climate is called its climatic climax

Question 49

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

Answer 49

finish this