Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

A Level: Biology > Ecosystems > Flashcards

Ecosystems Flashcards

1
Q

Define ecosystem

A

A physical area that Includes all living organisms and non living components and there interactions with each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define population

A

A group of organisms of the same species living in the same area at the same time and can breed together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define community

A

Populations of different species living together in the same area area and can interact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define habitat

A

A place where an organism lives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define niche

A

The role of an organism in its environment includes what it eats, habitat, competition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define species

A

A group of similar organisms that can interbreed to produce fertile offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define ecology

A

The study of interactions between living organisms and their environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define biotic factors

A

Living factors of an ecosystem

Disease, predation, competition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define abiotic factors

A

Non living factors

Temp, ph, light intensity, wind velocity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does it mean if an ecosystem is dynamic

A

It means they are constantly changing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is competition exclusion principle

A

When an organism shares the same niche and they outcompete each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

State and describe three types of ecological interaction that occur between different species in a habitat

Give an example of each

A 
-interspecific competition 
Grey and red squirrels 
- predator-prey interaction 
Lynx and hare 
-mutualism- both partners benefit 
Crocodile and Egyptian plover bird
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe mutualism

A

Where both partners benefit

Crocodile lies with its mouth open and Egyptian plover flies into the mouth and eats the decaying meat stuck in the teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is only 2% of the suns energy used by producers

A

90% reflected by leaf

Only some light wavelengths is used by chlorophyll in plants , most is transmitted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

3 reasons why energy is lost at each trophics level

A
  • heat during respiration
  • movement contraction
  • faeces/ indigestible material
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define the term producer

A

An organism that converts light energy into chemical energy through photosynthesis

Starts the food chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define consumer

A

Organisms that obtain energy by feeding on other organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a trophic level

A

Each stage of a food chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe a pyramid of numbers

A

Shows the numbers of the different organisms

Producers always at the bottom
Does not account for the size of organism
Caution- parasites have small sizes and large reproductive cycles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is biomass

A

Dry mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the measurements for biomass

A

gym^-2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What’s a disadvantage of a pyramid of biomass

A

They are difficult to get data for and organisms must be killed to

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Explain the process of finding biomass

A

Takes organism from environment and remove the soil

Dry in a oven at 105°c to evaporate water

Weigh until the mass remains the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the most accurate pyramid

A

Pyramid of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the units used in a pyramid of energy
kJm^-2 year^-1
26
What is the process of finding energy in a pyramid of energy
Takes organism from environment and remove soil Dry in oven at 105° to evaporate water Weigh until mass remains the same Burn in O2 and record temp rise of fixed volume of water using a calorimeter
27
What percentage of the suns energy is used by producers
2%
28
Why is the percentage of suns energy so low
90% reflected by leaf Only some light wavelengths used by chlorophyll Only some is absorbed most is transmitted I’m
29
What is the job of decomposed and detritivores
They break down organic molecules (proteins, carbohydrates) into inorganic molecules (CO2, nitrate and phosphate)
30
Define gross primary production
The total solar energy that is converted into organic matter in producers
31
Define net production
What’s left of the gross production after respiration has occurred
32
What’s the formula for % efficiency
(Energy after transfer / energy before transfer) x 100
33
What is the formula for net production
Gross production - respiratory loss
34
How can a plants net production be lowered How can this be monitored
- eaten by pests- pesticides - leaves fall off- shelter from wind - not enough water-irrigation - not enough light- use artificial light
35
How could photosynthesis be controlled
Light wave lengths can be controlled if dark Temperature controlled by heaters and ventilation C02 controlled by burning fossil fuels
36
How may productivity of livestock be increased
- prevent predators eating them- keep them fence in - killed by disease- give them vaccinations - high protein diets - restrict movement (avoid energy loss)
37
Define decomposition
The chemical process where larger organic molecules are broken down into smaller inorganic molecules
38
What are decomposers | And what do they do
Organisms that feed on and break down plant or animal matter They turn organic molecules into inorganic molecules
39
What are saprotrophs | What do they do
Obtain energy from dead or waste organic material Extracellular digestion which means enzymes are secreted outside the cells
40
What are detritivores
Organisms that feed on dead and decaying material They break it down into smaller pieces of organic material These increase surface area for decompsoers Speed up the rate of decomposition Perform internal digestion
41
Describe the carbon cycle
Carbon compounds in producers➡️carbon in primary consumers➡️ carbon in secondary consumers➡️decomposers Burn fossil fuels Decomposers and fossil fuels both release CO2 into air and oceans
42
What’s the formula for photosynthesis
Carbon dioxide n water= oxygen n glucose
43
Describe carbon levels during the day and night
During day- less CO2 lots of photosynthesis Night- more CO2 no photosynthesis
44
Which biological molecules contain nitrogen
Amino acids Proteins DNA RNA ATP
45
What makes nitrogen difficult to break
It is a triple bond
46
What percentage of nitrogen is in the air
78%
47
Describe Azobacter
Free living nitrogen fixing bacteria living in the soil Convert nitrogen in the air into ammonium ions using nitrogen add enzyme in the bacteria
48
Describe Rhizobium
Nitrogen fixing bacteria that live in root modules of leguminous plants like peas and clover It’s a mutualistic symbiotic relationship, plants gain amino acids and rhizobium gain glucose from plants from respiration
49
What does symbiotic mean
Live close to each other
50
Describe nitrification
An oxidation reaction Nitrosomonas bacteria oxidise ammonium compounds into nitrites Nitro after oxidise nitrites into nitrates Nitrates are highly soluble and are the form in which more nitrogen enters a plant
51
Describe non living nitrogen fixation
Lightning- electrical energy in lightning combines nitrogen and oxygen in the air to produce nitrites and nitrates
52
What do denitrifying bacteria do
Convert nitrates back into nitrogen gas Happens in anaerobic conditions in waterlogged soils
53
What process do decomposers do
Ammonification
54
What does succession occur as a result as
Changes in the abiotic factors of an environment Caused by decomposition of current species making environment suitable for new species Other species inter specifically outcompete earlier species and the process repeats until a climax community is formed
55
What is primary succession
Starts with the bare rock or sand There is no soil or organic material present to begin with This could occur after a volcanic eruption when all soil and dead matter has been destroyed
56
Explain secondary succession
Starts with a thin layer of soil such as in a forest clearing after a fire or flood
57
What’s is the technical term for the states of succession
Seral stages
58
Name two examples of pioneer species Name two properties
Lichens and mosses Can photosynthesis to produce their own food Can cope with extreme abiotic conditions
59
How do pioneer species arrive
As spores or seeds carried by winds from nearby land masses or from droppings of birds
60
What is humus
Dark organic material that forms in the soil when plant and animal matter decays Contains many useful elements for healthy soil
61
How do secondary colonisers arrive Give an example
As spores and seeds Mosses
62
Give an example of a tertiary coloniser
Ferns or grasses
63
What is scrubland
Small trees and shrubs with many deep roots now take over This changes in abiotic factors and they out compete the earlier species
64
What does a climax community consist of
Consist of animals and plants that have displaced earlier species Succession is now stopped, there are a few dominant species
65
What is animal succession
As the plant species change more habitats and food for consumers are created
66
What is deflected succession
Where succession is halted
67
Describe an example of deflected succession
Grouse- we burn the heather to prevent it reaching climax community, grouse shooters lay for heather to be burnt so they can shoot the grouse that depend on the heather If we didn’t do this, pine and birch would outcompete heather and the grouse would be displaced

A Level: Biology (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions