B7- Ecology Flashcards
What is ecology about
Organisms and the environment they live in, and how the two interact
Define habitat
The place where an organism lives
Define population
All the organisms of one species living in a habitat
Define community
The populations of different species living in a habitat
Define Abiotic factors
Non-living factors of the environment
Define Biotic factors
Living factors of the environment
Define Ecosystem
The interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of the their environment
What are Stonefly Larvae particularly sensitive to
Pollution
What is it called when all the species and environmental factors are in balance so that the population sizes are roughly constant
Stable communities
Examples of Abiotic Factors
- Moisture level
- Light intensity
- Temperature
- Carbon dioxide level (for plants)
- Wind intensity and direction
- Oxygen level (for aquatic animals)
- Soil pH and mineral content
Examples of Biotic Factors
- New predators
- Competition
- New pathogens
- Avalibility of food
Define structural adaptation
Features of an organism’s body structure-such as shape or colour
Define behavioural adaptation
These are ways that organisms behave. Many species migrate to warmer climates during te winter to aviod the problems of living in cold conditons
Define functional adaptation
These are things that go on inside an organism’s body that can be related to processes like reproduction and metabolism
What do food chains start with
A producer
Where do producers get their foofd from
The sun
Who eats the producer in a food chain
Primary consumer
Who eats the primary consumer in a food chain
Secondary consumer
Who eats the secondary consumers in a food chain
Tertiary consumer
Describe the stages of the water cycle
- Energy from the Sun makes water evaporate from the land and sea, turning it into water vapour. Water alos evaporates from the plants- this is known as transpiration
- The warm water vapour is carried upwards (as warm air rises). When it gets higher up it cools and condenses to form clouds
- Water falls from the clouds as precipitation (usually rain, but sometimes snow or hail) onto land, where it provides fresh water for plants and animals
- It then drains into the sea, before the whole process starts again
Describe the carbon cycle
- CO2 is removed from the atmosphere by green plants and algae during photosynthesis. The carbon is used to make glucose, which can be turned into carbohydrates, fats and proteins that make up the bodies of the plants and algae
- When the plants and algae respire, some carbon is returned to the atmosphere as CO2
- When the plants and algae ar eaten by animals, some carbon becomes part of the fats and proteins in their bodies. The carbon then moves through the food chain
- When the animals respire, some carbon is returned to the atmosphere as CO2
- When plants, algae and animals die, other animals (called detritus feeders) and microorganisms feed on their remains. When these organisms respire, CO2 is returned to the atmosphere
- Animals also produce waste that is broken down by detritus feeders and microorganisms
- The combustion (burning) of wood and fossil fuels also releases CO2 back into the air
- So the carbon (and energy) is constantly being cycled- from the air, through food chains (via plants, algae and animals, and detritus feeders and microorganisms) and eventually back into the air
Why do microorganisms break down plant and animal material and waste
For energy
What is compost
Decomposition of organic matter that is used as a natural fertiliser
What factors affect how quickly microorganisms decay stuff
- Temperature
- Oxygen availability
- Water availability
- Number of decay organisms
When is biogas made
By anaerobic decay of waste material
What is biogas mostly made up of
Methane
Does biogas need to be kept at a constant temperature
Yes
What are the two types of biogas generators
Batch generators and continuous generators
Describe what a batch biogas generator is
They make biogas in small batches. They’re manually loaded up with waste, which is left to digest, and the by-products are cleared away at the end of each session
Describe what is continuous generator is
They make biogas all the time. Waste is continuously fed in, and bioga is produces at a steady rate. Continuous generators are more suited to large-scale biogas projects
What 3 things do all biogas generators need to have
- An inlet for waste material to be put in
- An outlet doe the digested material to be removed through
- An outlet so that the biogas can be piped to where it is needed
Define biodiversity
The virality of different species of organisms on Earth, or within an ecosystem
What do carbon dioxide and methane do to heat
Trap it in the Earth’s atmosphere
What do trees and peat bogs do to carbon dioxide
Trap it
What are the negative impacts of deforestation
- More CO2 in the atmosphere
- Less biodiversity
What happen when a plant lives in a bog
It doesn’t fully decay
Why do plants i peat bogs not fully decay when they die
There isn’t enough oxygen
What are examples of programmes that have been set up to boost biodiversity
- Breeding programmes
- Protecting regenerate rare habitats
- To reintroduce hedgerows and field margins
- Reduce the level of deforesation
- People are encouraged to recycle and reduce the amount of waste
What are the down sides to protecting biodiversity
- Expensive
- A cost to local people’s livelihood
- Trying to protect our food security
- Devlopment is important
What is at trophic one (food chains)
Producr
What is at trophic 2 (food chains)
Primary consmer
What is at trophic 3 (food chains)
Secondary consumer
What is at trophic 4 (food chains)
Tertiary consumer
What do decomposers do
Break down uneaten remains and waste
What do pyramids of biomass show
The relative mass of each trophic level
What are reasons as to why biomass is lost at every leval
- Organisms don’t eat every part of the animal
- Organisms don’t absorb all of the stuff in the food they ingest
- Some of the biomass is taken in is converted into other substances that are lost as waste
What is the equation for efficiency of biomass
Biomass transferred to the next level / Biomass available at the previous level X 100
What factors impact food security
- Population
- Diets dvelop and change
- New pests and pathogens
- Price
- Conflict
What is the benefit of fishing quotas
There are limits on the number and size of fish that can be caught in certain areas. This prevents certain certain species from being overfished
What is being put in place to prevent overfishing
- Fishing quotas
- Net size
What ways are here to make food production more efficient
- Live stock can be factory farmed
- Fish can be factory farmed
- Animals being fed high-protein food
Why are some factory farming methods contreversial
Because of the cramped conditons disease can spread
-Ethical objections are that making animals live in unnatural conditions and uncomftable is cruel
What is biotechnology
Where living things and biological processes are used and manipulated to produce a useful product
What is mycroprotien
Food from fungi
Bacteria can be engineered to produce human _
Insulin
What is gentic engineering
Transferring a useful gene from one organ to another
How can biotechnology help with genetically modified crops
- Resistance to pests improving cropt yeild
- Make crops grow better
- More nutritional value
Why do some people disagree with gentically modified crops
- People argue that people are hungry because of poverty and that is the issue that is tackled
- Fears that countries may become dependent on companies who sell genetically modified crops
- Often poor soil is the issue so GM crops won’t survive
State the levels of organisation in an ecosystem
Individual, population, community, ecosystem
What is an ecosystem
The interaction between the living components and non-living components.
State the factors that plants may compete for
● Light
● Space
● Water
● Mineral ions from soil
State the factors that animals might compete for
● Food
● Mates
● Territory
What is intraspecific competition
Competition within a species
What is interspecific competition
Competition between different species
What is interdependence
Different species in a ecosystem depend
on each other for various resources, if
one species is removed, the whole
community may be affected
What is a stable community
A community in which all the biotic factors (the different species) and all abiotic factors are balanced so that population sizes remain relatively constant.
What are abiotic factors
Non-living factors
State the abiotic factors that may affect
an ecosystem
● Light intensity ● Temperature ● Moisture ● Soil pH and mineral content ● Wind intensity and direction ● Carbon dioxide level ● Oxygen level
Why might light intensity affect an ecosystem?
Different species of plants may have different
optimum light intensities for growth.
Why does temperature affect an ecosystem
Different species of plants and animals may
have different optimum temperatures for
growth and survival.
How does soil pH affect an ecosystem
Certain plants may grow better in either
alkaline or acidic soil.
Soil pH may affect the appearance of the
plant eg. colour of hydrangea.
How does moisture level affect an ecosystem
Many plants cannot survive in waterlogged
soil as their roots cannot respire.
Certain plants are adapted to high moisture
levels
How does wind intensity affect an ecosystem
Plant seeds are more likely to germinate in
locations with lower wind intensity, which may
also attract animals that depend on the plant
to live nearby.
How does soil mineral content affect an ecosystem
Most plants require a high level of soil
minerals to grow well.
Give an example of a type of plants that have
adapted to low soil mineral content
Carnivorous plants catch insects to
compensate for the low level of soil mineral
content
How does carbon dioxide concentration affect an
ecosystem
Higher carbon dioxide concentration leads to
more plant growth
How does oxygen concentration affect an
ecosystem
Aquatic animals cannot survive in areas with
low oxygen concentration
State the biotic factors that may affect an
ecosystem.
● Food
● New predators
● New pathogens
● Competition
What are adaptations
Features that enable organisms to survive in their living environment.
What are organisms living in extreme environments
called
Extremophiles
Give 3 examples of extreme living environments
● High temperature
● High pressure
● High salt concentration
State an example of where extremophile bacteria
can be found
In deep sea vents
Define population
A species that occupy the same habitat
Define habitat
The place in which an organism lives
Define community
Populations of different species interacting
Define ecosystem
The interactions between the biotic and
abiotic factors in an area
What do food chains show?
Food chains show the feeding relationships of
different organisms and the flow of energy between
the organisms
Define biomass
The total mass of living material.
What are trophic levels
The stages in a food chain.
What do arrows in a food chain represent
The direction of biomass transfer
Describe a simple food chain
producer → primary consumer → secondary consumer → tertiary consumer
What is a producer?
An organism that makes its own food
What types of organisms are primary producers
Photosynthetic organisms like green
plants and algae that trap energy from
the sun
What is a primary consumer
An organism that feeds on producers
What is a secondary consumer
An organism that feeds on primary
consumers.
What is a tertiary consumer
An organism that feeds on secondary
consumers
What is a predator
A consumer that kills and eats other
animals
What is prey
An animal that is killed and eaten by another animal
Describe the pattern of predators and prey in a
stable community
The numbers of predators and prey rise
and fall in cycles
Why are producers the first trophic level
● Producers provide all biomass for the food
chain (production of glucose via
photosynthesis).
● The rest of the food chain involves the transfer
of this biomass
What piece of apparatus is used to measure the
abundance and distribution of organisms in an area
Quadrat
What piece of apparatus is used to study the
distribution of organisms across a gradient?
Belt transect
When considering the abundance of organisms,
what is meant by the term “mean”
The average number of organisms
How is the arithmetic mean calculated
Sum of each number of each
organism/the total number of each type
of organism
When considering the abundance of different
organisms, what is meant by the term “mode”
The most populous organism
When considering the abundance of organisms,
what is meant by the term “median”
The organism that represents the middle
value when the numbers of each
organism are arranged from lowest to
highest
Describe how materials cycle through
the living and non-living components of
an ecosystem
● Organisms take in elements from their surroundings e.g. soil, air.
● Elements converted to complex molecules which become biomass.
● Elements transferred along food chains.
● Elements returned to environment during excretion and
decomposition of dead organisms.
Give 3 molecules which are cycled through
ecosystems
Oxygen, carbon dioxide and water.
Describe the carbon cycle
- Plants fix carbon dioxide into organic molecules during
photosynthesis. - The organic carbon-containing molecules are passed onto organisms
that eat the plants. - Carbon dioxide is released back into the atmosphere by respiration
from animals and plants. - Burning fossil fuels also releases carbon dioxide into the atmosphere
Why is the carbon cycle important
Carbon-containing molecules such as
glucose are important for living
organisms to grow and provide energy
for vital functions within cells.
Describe the water cycle
- Water from lakes and oceans evaporates.
- The evaporated water condenses into clouds and returns
to earth as precipitation. - The water from precipitation is useful for life on land.
- The water then returns to rivers and oceans through
surface runof
Why is the water cycle important?
Living organisms require water and the
water cycle provides organisms on land
with a continuous supply of water
Why are microorganisms important for the cycling of
materials through an ecosystem
Microorganisms (bacteria and fungi) return carbon to the environment by releasing carbon dioxide through
respiration while they decompose dead matter. The
decomposition of dead matter in soil returns mineral ions to
the environment for other organisms to use e.g. plants use mineral ions for growth
What is meant by decomposition
The breakdown of dead materials into simpler organic matter
How do decomposers break down dead matter?
Decomposers release enzymes which
catalyse the breakdown of dead material
into smaller molecules
What are the two types of decomposition
Aerobic decomposition (with oxygen) Anaerobic decomposition (without oxygen)
What factors affect the rate of decomposition?
● Oxygen availability
● Temperature
● Water content
Why is oxygen required for decomposition
Most decomposers require oxygen for
aerobic respiration.
How does the availability of oxygen affect the rate of
decomposition
● As oxygen levels increase, the rate of
decomposition increases.
● As oxygen levels decrease, the rate of
decomposition decreases.
Why can decomposition still occur in the absence of
oxygen?
Some decomposers respire anaerobically.*
*However, the rate of decomposition is slower as
anaerobic respiration produces less energy.
How does soil water content affect the rate of
decomposition
Decomposers require water to survive:
● In moist conditions the rate of decomposition is high.
● In waterlogged soils there is little oxygen for
respiration so the rate of decomposition decreases.
Why does decomposition require water
Water is required for the secretion of
enzymes and absorption of dissolved
molecules.
How does temperature affect the rate of
decomposition
Decomposers release enzymes:
● Rate highest at 50°C (optimum temperature for enzymes).
● Lower temperatures, enzymes work too slowly, rate decreases.
● High temperatures, enzymes denature, decomposition stops.
How is the rate of change calculated when
considering the decay of biological material
Rate of change = Change in value ÷ Change in time
Where value is a measurable variable associated with
the decay of the material
What is compost
The nutrient-rich product of the rapid
decay of waste biological material (dead
plants and animal waste) in optimum
conditions set by gardeners and farmers.
How is compost used
Used as natural fertiliser to promote
growth of crops or garden plants
Describe how biogas generators work
Biogas generators provide methane gas
for fuel through anaerobic decomposition
that occurs in animal waste.
Describe how environmental conditions affect
communities
● Environmental conditions e.g. temperature, soil pH, light intensity affect the abundance and distribution of organisms within communities.
● e.g rising global temperatures have been linked to the extinction of frog species (their thin skin makes them more vulnerable to temperature changes).
How can different temperatures be bad for certain
communities
- If the temperature is too low, growth will be slower
as organisms will use more energy to stay warm - If the temperature is too high, organisms can die
and water will become limited as evaporation
increases
How can changes in water levels affect ecosystems
- Animals may have to migrate to find water.
- Melting ice caps may destroy the habitats of
some animals (either animals living in icy
regions or by sea level rise).
How can atmospheric gases affect ecosystems?
- Some organisms cannot survive when
certain gases are present. - Polluted water can cause illness to
animals that drink it.
What detrimental impacts can sulfur dioxide have on
the environment
- Formed when fossil fuels containing impurities are burnt. - Sulfur dioxide can dissolve in water to form acid rain which can erode buildings and pollute water sources.
What detrimental impacts can carbon monoxide
have on the environment
- Carbon monoxide is formed from the incomplete
combustion of fossil fuels. - Carbon monoxide binds irreversibly to haemoglobin
which prevents it from carrying oxygen. - Too much exposure can cause unconsciousness and
death.
Name 5 greenhouse gases
- Water vapour
- Carbon dioxide
- Nitrous oxide
- Methane
- CFCs
Give 3 human activities that contribute to
greenhouse gases
- Burning fossil fuels
- Deforestation
- Large scale livestock farming
How do greenhouse gases lead to global warming?
- Greenhouse gases allow heat from the
sun to enter the atmosphere. - The gases act as a ‘blanket’ and trap
the heat in the atmosphere
State 3 negative consequences of global warming
- Sea level rise caused by melting icebergs.
- Disrupted farming and agriculture.
- Increased spread of diseases in warmer
climates.
What is biodiversity
The variety of the different species on
earth or within an ecosystem
What is the importance of biodiversity
To maintain the stability of an ecosystem.
How does biodiversity ensure the stability of an
ecosystem
It reduces the dependence on particular
species for resources eg. food and shelter, so
that even if one species is removed other
species can still survive
Why have humans’ consumption of resources and
waste production increased
● Rapid rise in human population
● Increase in standard of living
Where does pollution occur?
● Air
● Land
● Water
State an example of water pollutants
● Sewage
● Fertiliser
● Chemicals
How does eutrophication occur
Fertiliser from farms pollute the water, causing excessive
algae growth, depleting the oxygen in the water, causing
other plants and animals to die.
Dead plants are decomposed by bacteria and the oxygen
level decreases further.
State an example of air pollutants
● Smoke
● Acidic gases
State an example of land pollutants
● Landfill waste
● Chemicals
Which human activities reduce the land available for
animals and plants
● Building
● Farming
● Quarrying
● Disposing of waste
Why have peat bogs been destroyed?
To produce compost to increase food
production.
Why does the destruction of peat bogs greatly
contribute to the greenhouse effect
Peat bogs are stores of carbon (carbon
sinks) and burning them releases a large
volume of carbon dioxide into the
atmosphere
Why have large-scale deforestation activities
occurred?
● To provide land for cattle or rice fields
● To grow crops to produce biofuels
What is the greenhouse effect
Greenhouse gases trap energy from the
Sun as heat in the atmosphere, keeping
the temperature on earth suitable for life.
What is causing global warming
The increase in levels of greenhouse
gases eg. carbon dioxide and methane,
causing the temperature on earth to
increase
What are the harmful effects of deforestation
● Destruction of many animals’ habitats
● Releases large amounts of
greenhouse gases
State the consequences of global warming
● Rising sea levels ● Melting polar ice caps ● Changing weather patterns ● Migration of animals to find suitable habitats ● Tropical diseases becoming more common ● Extinction of species
Describe the steps taken to maintain biodiversity
● Breeding programmes for endangered species.
● Protection and rebuilding habitats.
● Replanting field margins and hedgerows.
● Reduce deforestation.
● Reduce carbon dioxide emissions.
● Recycling rather than disposing in landfills.
What is the purpose of replanting hedgerows and
field margins
There is higher biodiversity in the
margins than the fields that they
surround
What does a food chain show
It describes the feeding relationships
between organisms and the resultant
stages of biomass transfer
What are trophic levels?
The stages in a food chain
How are trophic levels represented
Trophic levels are represented by
numbers, starting from 1. After 1, trophic
levels are numbered according to far
along the organism is in the food chain
What is trophic level 1?
Plants and algae which make their own
food (through photosynthesis) - called
producers
What is trophic level 2
Herbivores which eat producers - called
primary consumers
What is trophic level 3?
Carnivores that eat herbivores - called
secondary consumers
What is trophic level 4
Carnivores that eat other carnivores -
called tertiary consumers
What is an apex predator
A carnivore with no predators
How do decomposers break down dead matter
Decomposers release enzymes which catalyse the breakdown of dead material into smaller molecules. Soluble small food molecules then diffuse into the microorganisms
What is biomass
The dry mass of all of the living organisms in an area
Why is dry mass used for biomass
Because the wet mass varies as the
volume of water in the organism varies.
How do you calculate the efficiency of biomass
transfer
efficiency = (energy transferred / total energy available) × 100
What percentage of the incident energy from light for
photosynthesis do producers transfer
1%
What percentage of the biomass from one trophic
level is transferred to the level above it in feeding?
Approximately 10%
Why are biomass transfers not 100% efficient
Energy is lost through:
- Egestion (removal of faeces)
- Excretion (removal of waste products e.g. urine
containing urea and water)
- Respiration (loss of carbon dioxide and water) in which
large amounts of glucose are used
- The production of inedible bones and shells
How does the efficiency of biomass transfers affect
the number of trophic levels in a biomass pyramid
The less efficient the transfers, the fewer
trophic levels and the fewer organisms in
higher trophic levels
What is a biomass pyramid
A pyramid that shows the total dry mass of
organisms at each trophic level
Trophic level 1 is at the bottom of the
pyramid
What is a pyramid of numbers
A pyramid of numbers shows the number
of organisms at each trophic level
Why is this pyramid of numbers not pyramid
shaped?
Pyramids of numbers don’t take size and
mass of organisms into account
What is food security
Having enough food to be able to feed a
population
State the biological factors threatening food security
● Rising birth rates
● Changing diets in developed countries → food is
transported around the world
● New pests and pathogens
● Environmental changes affecting food production
● Increased cost of agriculture
● Armed conflicts
How does intensive farming increase the production
of animals
● Feed animals high protein foods to increase growth.
● Reduce their energy loss to the environment:
○ Limiting movement
○ Regulating their surrounding temperature
● Feed animals antibiotics to prevent diseases.
What are the advantages of intensive farming
● Higher yield of food
● More efficient
● Allows easier quality control
What are the disadvantages of intensive farming
● May lead to antibiotic resistance. ● Cost is high. ● Ethical objections eg. limiting movement of animals may cause them harm. ● Biodiversity may be reduced
How can fish stocks be conserved
● Control the size of gaps in fishing nets to
prevent juvenile fish from being killed.
before reaching reproductive maturity
● Introduce fishing quotas.
What is a transgenic organism
An organism that has been genetically
modified to contain genetic material from
another source
State an example of genetically modified foods
Golden rice
How might crops be genetically modified
● To improve nutritional value
● To be pest resistant
● To be pesticide resistant
What are the advantages of golden rice
It contains additional beta-carotene which can
be converted to vitamin A in the body,
supplementing people who do not obtain
enough Vitamin A in their diet to prevent night
blindness from forming
What is mycoprotein
A protein-rich substance used to make
meat substitute food for vegetarians and
vegans
How is mycoprotein produced
Fusarium, a fungus, is grown on glucose
syrup, in aerobic conditions and the
biomass is harvested and purified to get
the mycoprotein
