7C Populations in ecosystems Flashcards

1
Q

What is an ecosystem?

A

This is where all the organisms living in a community plus all the abiotic conditions as well

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2
Q

What are biotic conditions

A

Living features of an ecosystem eg predators

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3
Q

What are abiotic condition?

A

Non living features eg temp or soil

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4
Q

What is the place an organism lives?

A

Habitat

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5
Q

What is a niche?

A

This is the role of a species within a habitat eg what it eats, when and where it feeds

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6
Q

What does the niche a specie occupy include

A
  • Its biotic interactions : eg the organism it eats and those its eaten by
  • Its abiotic interactions : eg the temp range an organism can live, the time of day it is active
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7
Q

What will happen if 2 species try to occupy the same niche?

A

They will compete until one specie is left as one is more successful than the other

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8
Q

What is an adaptation?

A

A feature that members of a species have that increases their chance of survival and reproduction

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9
Q

What are the types of adaptations?

A

Physiological - processes inside their body
Anatomical - structural features
Behavioral - the way an organism acts

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10
Q

What is a population?

A

A population is all the organisms of one species in a habitat

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11
Q

What is a community?

A

populations of different species in a habitat make up a community

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12
Q

What is population size

A

Total number of organisms of one species in a habitat

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13
Q

What is the carrying capacity ?

A

Total number of organisms of one species in a habitat

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14
Q

What is interspecific competiton?

A

Organisms of different species compete with eachother for the same resources.

If two species are competing but one is better adapted to the surroundings than the less well adapted species is likely to be outcompeted

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15
Q

What is intraspecific competition?

A

Organisms for the same species compete with eachother for the same resources

If the population grows beyond the carrying capacity there wont be enough resources for all organisms and the population will decline, so there is less competition for space and food which is better for growth and reproduction so the pop can grow again

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16
Q

What is predation?

A

Organisms kill and eats another organism

Population sizes of predator and prey are interlinked so as the pop of one changes the pop of another will change

17
Q

What is abundance

A

This is the number of individuals of one species in a particular area

18
Q

How do you measure abundance

A
  • Frequency : the number of samples a species is recorded in
  • Percentage cover : how much of the area you’re investigating is covered by a species
19
Q

How does random sampling work ?

A
  1. Choose an area to sample
  2. Should be random to avoid bias therefore use a random number generator
  3. Use an appropriate technique eg quadrats and transects
  4. Repeat so less results are due to chance
  5. Take mean of all samples
20
Q

What is a running mean

A

Work out the mean of all the data each time you collect a new sample

21
Q

What are the methods for investigating populations

A

Quadrats
Transects

22
Q

How does quadrats work

A

It is a square frame divided into a grid of 100 smaller squares

  1. Placed on the ground at different points
  2. Measure species frequency or number of individuals of each species
23
Q

How does transects work and the different types

A
  1. Belt Transects : quadrats placed next to eachother along transect to work out species frequency and percentage cover along transect
  2. Interrupted Belt Transects : Instead of investigating the whole transect you can take measurements using a quadrat placed at regular intervals
24
Q

How do you capture motile organisms

A
  • Net
  • Pitfall trap
25
Q

What is Mark Release capture?

A
  1. Capture a sample of species using an appropriate technique
  2. Mark in a harmless way
  3. Release back into habitat
  4. Wait a week, and take a 2nd sample from same population
  5. Count how many of second sample are marked
26
Q

How do you calculate Mark Release capture?

A

number caught in 1st sample x number caught in 2nd sample /
number marked in 2nd sample

27
Q

How do you ensure Mark Release capture method is accurate ?

A
  • The marked sample has enough time and opportunity to mix back in with the population
  • The marking hasnt affected the individuals chances of survival and is still visible
    -There are no changes in population size due to birth, migration and deaths
28
Q

What is succession

A

The process by which an ecosystem changes over time

29
Q

What is primary succession

A
  1. Species colonise a new land surface
  2. Seeds and Spores are blown in by the wind and begin to grow
  3. First species to colonise area are called PIONEER SPECIES
  4. Only pioneer species cope as they have adapted to cope with harsh conditions
  5. The new organisms then die and are decomposed adding more organic material so the soil is richer in materials
  6. Nitrogen fixing bacteria turn nitrogen from the atmosphere into ammonia forming ammonium ions so it can be used
  7. Dominant species will out compete the plants and animals already there
  8. Ecosystem becomes more complex as more species move in, plants create more habitats, abiotic conditions less hostile and biomass increases
    9.Climax community
30
Q

What are some examples of hostile abiotic conditions

A
  • Limited water available as theres no soil to retain water
  • Few minerals or nutrients as theres no soil
  • High Light intensity and fluctuating temperatures
31
Q

What is secondary succession

A

This happens on land that has been cleared of all the plants buy where the soil remains

32
Q

What is plagioclimax

A

This is where succession was stopped artificially

33
Q

What is a climatic climax community

A

Where the climax community is dependent on the climate in an ecosystem

34
Q

What is conservation

A

The protection and management of species and habitats in a sustainable way but as a dynamic process

35
Q

How is seed banks a conservation method?

A

They act as backup for the conservation of plant species

36
Q

How is captive breeding a conservation method?

A
  • Breed Animals in controlled environments so they can then be reintroduced into the wild
37
Q

How is fishing quotas a conservation method?

A

Limit to the amount of fish species that fishermen are allowed to catch so less are killed

38
Q

How is protected areas a conservation method?

A

They restrict urban development, industrial development and farming