Ecology Flashcards
What is the source of energy for most living organisms?
Radiation from the Sun
What percentage of the incident energy from light is transferred for photosynthesis?
1%
Where is this incident energy stored?
In the substances that make up the cells of plants
The further up a food chain (trophic level)…
The less energy and less biomass
What do pyramids of biomass show?
The relative mass of living material at a tropic level (i.e. how much all the organisms would “weigh” if you put them all together)
How much of biomass from each trophic level is transferred to the level above it?
Approximately 10%
Why is biomass lost between each trophic level (energy wasted)?
- Organisms don’t eat very single part of organism they’re consuming
- Don’t absorb all stuff in food they ingest (egested as faeces) - lost in organisms’ waste materials
- Some biomass is converted into other substances that are lost as waste
Give an example of some biomass being converted into other substances and that are lost as waste
Organisms use a lot of glucose in respiration to provide energy for movement and keeping warm (rather than make more biomass) + energy from respiration is transferred by heating surroundings
What does respiration produce as waste?
Carbon dioxide and water
Give another example of some biomass being converted into other substances and that are lost as waste (that’s not to do with respiration)
Urea is waste - released in urine with water when proteins in biomass are broken down
How can you calculate the efficiency of a biomass transfer?
Biomass transferred to next level
——————————————————— x 100
Biomass available at the previous level
How can the efficiency of food production be improved?
By reducing the number of stages in a food chain
What does a food chain show?
Shows what’s eaten by what
Plants make glucose by photosynthesis. Some glucose produced is used to make other biological molecules in plant. What are these molecules known as?
The plant’s biomass
What is biomass and what can it be thought as?
It is the mass of living material
Can be thought as energy stored in plant
How is energy is transferred through living organisms in an ecosystem?
By organisms eating other organisms
Populations of prey and predators go in…
cycles
What is the population of any species limited by?
The amount of food available
Explain how populations of prey and predators go in cycles
- If population of prey increases = population of predators will increase
- However, as population of predators increases, number of prey will decrease
Why are predatory-prey cycles always out phase with each other?
Because it takes a while for one population to reasons to changes in other population
E.g. When number of rabbits goes up, number of foxes doesn’t increase immediately because it takes time to reproduce
How can we increase the efficiency in food production? (e.g. with livestock)
- Can limit movement of livestock
- Keep them in a temperature-controlled environment
= reduces transfer of energy from livestock to environment
How does limiting the movement of livestock/controlling the temperature make farming more efficient?
- Animals use less energy moving around & controlling their own body temperature
- Means more energy is available for growth = more food can be produced from same input of resources
What is intensive farming?
Where animals are restricted and kept in confined spaces
Name 3 advantages of intensive farming
- More biomass and energy in animals
- Mass production = more profit
- Free from predators
- Cheaper?
Name 3 disadvantages of intensive farming
- More disease is likely to spread
- Animal behaviour can change
- Morally wrong
What are extremophiles?
Organisms that live in environments that are very extreme
How are materials (e.g. carbon, oxygen, hydrogen) that are removed from the environment (by living organisms for growth, etc) returned to environment?
In waste products or when organisms dies and decays
Why do materials decay?
Because they’re broken down by microorganisms
Decay happens faster in what conditions i.e. when are microorganisms most active?
- Warm
- Moist
- Aerobic (oxygen rich) - to respire
How is CO2 removed from atmosphere?
By green plants and algae during photosynthesis
What is carbon used in plants for?
To make glucose = (carbon) turns into carbohydrates, fats and proteins which make up bodies of plants and algae
How is carbon returned back to the atmosphere? Two ways
- When plants and algae + animals + microorganisms respire, carbon is returned to atmosphere as CO2
- Combustion of wood and fossil fuels also release CO2 back into air
How does carbon move though the food chain?
- When plants and algae are eaten by animals some carbon becomes part of fats and proteins in body
- When plants, algae, animals die: other animals and microorganisms feed on remains
What is name of animals that eat other dead animals?
Detritus feeders
What is animals’ waste broken down by?
Detritus feeders and microorganisms
What is the carbon cycle?
The constant cycling of carbon
Decay processes release substances…
that plants need to grow
What is compost?
Decomposed organic matter (e.g. food waste)
What can compost be used as?
Used as national fertiliser for crops & gardens
What are responsible for decomposition (decay)?
Microorganisms (e.g. bacteria and fungi) & detritus feeders
What is the rate of decay affected by? (name 4 things)
- Oxygen Availability
- Water Availability
- Temperature
- Number of Decay Organisms
Explain how oxygen availability affects the rate of decay (or may not)
Many organisms need oxygen to respire = need to do to survive
But microorganisms involved in anaerobic decay = don’t need oxygen
Explain how water availability affects the rate of decay
Decay takes place faster in moist environments bc organisms involved in decay need water to carry out biological processes
Explain how temperature affects the rate of decay
Warmer temperatures = things decompose quicker bc they increase rate that enzymes involved in decomposition work at
If it’s too hot, what happens to decomposition and why?
Decomposition slows down or stops bc enzymes are
denatured & organism dies
If it’s too cold, what happens to decomposition?
Slows down
Explain how the no. of decay organisms affects the rate of decay
More microorganisms and detritus feeders there are = faster decomposition happens
What is a habitat?
Place where an organism lives
Define community
The populations of different species living in a habitat
Define population
All organisms of one species living in a habitat
Define ecosystem
The interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment
What are biotic factors?
Living factors of environment
What are abiotic factors?
Non-living factors of the environment
What do plants compete for? (name 4 things)
- Space
- Light
- Water
- Mineral ions (nutrients)
What do animals compete for? (name 4 things)
- Space (territory)
- Water
- Food
- Mates
What are adaptations?
Features or characteristics that helps organisms to survive
Why do artic animals have white fur?
To camouflage: helps avoid predators and sneak up on prey
How do whales retain heat? (name 2 features)
Have thick layer of blubber and a low surface area to volume ratio
Why do camels have a thin layer of fat and large surface volume ratio?
Less warm is trapped, reducing insulation + helps them lose heat
Name 3 structural adaptations of animals in cold climates
- Small Ears
- Thick fur
- Large Body Size
Why would artic animals have small ears?
Reduces surface area to volume ratio so less heat is released
Why would artic animals have thick fur?
Insulates body against cold
Why would artic animals have a large body size?
Reduces surface area and reduces heat loss from the body
Name 3 structural adaptations of animals in hot climates
- Hump of Fat
- Large Ears
- Long Legs
Why would a desert animal have a body tolerance to high temperatures?
Animals don’t sweat as much in hot weather = reducing water loss
Why would a desert animal have large ears?
Increases surface area to volume ratio = increase heat loss
Why would a desert animal have a hump of fat?
Fat is stored which can be metabolised into water
Why would a desert animal have long legs?
To lift body away from hot sand
Name 3 things plants need to do
- Retain water usually lost through their pores (stomata)
- Absorb as much light as possible from leaves
- Collect as much water from soil
Name 4 structural adaptations of plants
- Spines/spikes
- Large spread out roots (dry environment)
- Waxy layer on leaves
- Big leaves
Why would a plant have spines/spikes? (name 2 reasons)
- Reduce water loss
2. To prevent being eaten
Why would a plant have large spread out roots?
To collect water
Why would a plant have a waxy layer on leaves?
To reduce water loss
Give an example of a behavioural adaptation
Many species (e.g. Swallows) migrate to warmer climates during winter to avoid problems of living in cold conditions
What is a functional adaptation?
Inside an organism’s body: related to processes like reproduction and metabolism (chemical reactions in body)
Give a functional adaptation of desert animals
Conserve water by producing very little sweat and concentrated urine
Give a functional adaptation of brown bears and why they do this
Brown bears hibernate over winter = lowers their metabolism which conserves energy = don’t have to hunt when there’s not much food
Give an example of an extremophile
Microorganisms (bacteria)
Some microorganisms can live in… (state 3 conditions)
- High pressure (e.g. Deep sea vents)
- High temperatures (e.g. Super hot volcanic vents)
- High salt concentration (e.g. Very salty lakes)
What are parasites adapted for?
For living on or inside their host cells
Where do fleas live and what do they do?
Live amongst hair of mammals and suck blood of hosts
Name 4 adaptations of fleas
- Very long and powerful hind legs
- Saliva contains special chemical
- Have hard bodies
- Have sharp mouthparts
- Have flattened bodies
Why do fleas have very long and powerful hind legs?
Can jump from host to host
Why do fleas have saliva containing special chemicals?
To stop blood from clotting and blocking their mouthparts as they drink it
Why do fleas have hard bodies?
So they’re not damaged when animal scratches
Why do fleas have sharp mouthparts?
Can pierce skin of host + suck blood
Why do fleas have flattened bodies? (name 2 reasons)
- They can move easily between hairs
2. Not easily dislodged from host
Where do tapeworms live?
Inside intestines of mammals
Do tapeworms feed off a host? Explain your answer
No, but instead deprive them of their digested food
Name 4 adaptations of tapeworms
- Have head with hooks or/and suckers
- Body: thousand very thin, flattened segments = produce many eggs every day
- Don’t have gut - are long, flattened shape
- Has thick outer cuticle
Why do tapeworms have heads with hooks or/and suckers?
To attach them firmly to gut wall
Why do tapeworms produce many eggs every day?
Eggs eaten by other animal = life cycle begins
Why don’t tapeworms have a gut?
Absorb nutrients directly across skin
Why are tapeworms a long, flattened shape?
So can have large surface area
Why do tapeworms have a thick outer cuticle?
Protects them from digestive enzymes of hosts
What are malaria parasites?
Single-celled organism that cause malaria in humans
What is special about malaria parasites (adaptation wise)?
Have a number of different forms that are adapted to living in different regions of both mosquitoes and humans
Name 4 adaptations of malaria parasites
- Huge reproductive rates
- Uses very efficient vector
- Parasite mutates rapidly
- Different reproductive stages in life cycle = perfectly adapted to living in a different place in host
Why do malaria parasites use a vector?
To move from one host to next
Why do malaria parasites mutate rapidly?
Makes it almost impossible for people to develop immunity against it or produce a successful vaccine, or develop a drug that continues to work against it
Why is high biodiversity important?
Makes ecosystems stable - different species help maintain
right physical environment for each other (e.g. Soil acidity)
What is biodiversity?
The variety of different species of organism on Earth, or within a ecosystem
Why is it that increasingly more waste produced?
Rapid growth in human population and standard of living
Name 3 things waste may pollute
- Water
- Land
- Air
Explain how humans are polluting water (name 2 ways)
- Sewage and toxic chemicals from industry can pollute lakes, rivers and oceans
- Chemicals used on land (e.g. Fertilisers, pesticides and
herbicides) can be washed in water
Why is water pollution bad?
It affects plants and animals that rely on the water sources for survival (including humans)
Explain how humans are polluting land (name 3 ways)
- Toxic chemicals for farming (e.g. Pesticides and herbicides)
- Bury nuclear water underground
- Dump a lot of household waste in landfills
Explain how humans are polluting the air
Smoke and acidic gases released into atmosphere can pollute air
What can sewage & fertilisers cause?
Eutrophication
What is eutrophication? (explain process in depth)
- Increase in concentration of mineral ions in water (due to fertilisers) = stimulates growth of algae and/or plants
- Plants don’t receive enough light for photosynthesis so die
- There’s large increase in population of microorganisms that feed on these dead organisms
- Respiration of microorganisms depletes oxygen concentration in water = death of aerobic organisms
Why are trees chopped down? (name 2 reasons)
- Clear land for farming to provide more food
2. To crow crops from which biofuels based on ethanol can be produced
Name effects of deforestation (2 effects)
- Less carbon dioxide taken in
2. Less biodiversity
Explain how deforestation leads to less carbon dioxide being taken in (name 2 ways)
- Cutting down loads of trees = amount of CO2 removed from atmosphere during photosynthesis is reduced
- Trees ‘lock up’ some carbon that they absorb during
photosynthesis in their wood (can remove it from atmosphere for hundreds of years) removing trees = less CO2 locked up
Explain how deforestation leads to more carbon dioxide in the atmosphere (name 2 ways)
- CO2 is released when trees are burnt to clear land
2. Microorganisms feeding on bits of dead wood = release CO2 as waste product of respiration
Explain how deforestation leads to less biodiversity
- Habitats contain huge no. of different species of plants & animals
- When destroyed = many species may become extinct
What are bogs?
Areas of land that are acidic & waterlogged
What happens to plants that live in bogs when they die and why?
Don’t fully decay bc there’s not enough oxygen
What are peats made out of?
Build up of partly-rotted plants
What is stored in the plants in peats instead of being released into atmosphere?
Carbon
What often happens to peat bogs?
Often drained so area can be farmland or peat is cut & dried to use a fuel (and compost)
What happens when peats are drained?
They come into more contact with air & microorganisms start to decompose it
Why is it bad that microorganisms decompose the dried peat?
When microorganisms respire = Use oxygen and release CO2 = global warming
Why is bad to destroy bogs?
Destroys habitats of some animals, plants & microorganisms = reducing biodiversity
What contributes to global warming?
Increasing levels of carbon dioxide & methane in atmosphere
Name 5 consequences of global warming
- Changes in Species Distributions
- Changes in Migration Patterns
- Sea Levels Rising
- Reduction in Biodiversity
- Big Changes in Earth’s Climate
Distribution of many wild animals and plant species may change as…
Temperatures increase + amount of rainfall changes in different areas
State 2 ways how species distributions may change due to global warming
- Some species may become more widely distributed
2. Other species may become less widely distributed
Explain why some species may become more widely distributed due to global warming?
Species that need warmer temperatures may spread further as conditions they thrive in exist over wider area
Explain why some species may become less widely distributed due to global warming?
Species that need cooler temperatures may have smaller ranges as conditions they thrive in exist over smaller area
How might global warming affect migration patterns?
Some birds may migrate further north as more northern
areas are getting warmer
Explain how global warming causes sea levels to rise
Higher temperatures = seawater to expand & ice to melt = sea level rises
How are rising sea levels bad for and why?
Bad for people & animals living in low-lying places - leads to flooding = loss of habitats
Explain how global warming causes a reduction in biodiversity
If some species are unable to survive in changing climate = become extinct
Name 3 adaptations of nocturnal animals
- Big eyes
- Whiskers
- Large ears
Why do nocturnal animals have big eyes?
To help them see in the dark
Why do nocturnal animals have whiskers?
To help them avoid obstacles
Why do nocturnal animals have large ears?
To hear predators/prey
Define leeching
When fertilisers/pesticides/herbicides run through soil to water
Define bioaccumulation
When toxins build up in a food chain
Who is affected the most by bioaccumulation?
Animals at top of food chain
Describe bioaccumulation
- Small amounts of toxic substances (often from human activity) taken up by plants
- These plants are eaten by primary consumers, then secondary… etc.
- Harmless substances are excreted but toxins remain in the tissues of the organisms
Why are animals at top of food chain affected the most by bioaccumulation?
Bc concentration of toxin becomes most concentrated in them
What are 2 effects caused by producing more food?
- More methane produced = global warming
2. More food miles = more transport = more CO2
Name an effect on food chain caused by humans
Bioaccumulation
