Ecology (& HL Ecology) Flashcards
Definition of ecology?
the study of organisms and their environment.
Definition of biosphere?
the part of the earth where life can exist.
Definition of ecosystem?
organisms and their environment.
Definition of habitat?
place where an organism lives.
Definition of population?
all the organisms of the same species living in an area.
Definition of community?
all the organisms in an area/habitat/ecosystem.
Definition of niche?
refers to the role an organism plays in a community.
What are some examples of biosphere?
deep in the ocean, rock, air, soil.
What are examples of an ecosystem?
grassland, woodland, bogland, deserts, lakes.
What are examples of a habitat?
grassland, seashore.
What is an example of a population in their area/habitat?
rabbits in a field.
What does abiotic factors mean?
non-living factors.
What does biotic factors mean?
living factors.
Definition of climatic factors?
the weather over a long period of time.
Definition of edaphic factors?
relate to the soil.
Definition of aquatic factors?
relate to water.
What are factors of sandy soil/large soil particles?
- good drainage
- good air content
- low mineral content
- low water content
What are factors of clay soil/small soil particles?
- impermeable to water
- impermeable to air
- poor drainage
- high mineral content
What is the primary source of energy flow?
the sun.
What percentage of energy is passed on to another organism?
10%
Definition of producers?
organisms that make their own food by photosynthesis.
Definition of consumers?
cannot make their own food.
Definition of primary consumers?
feed on producers.
Definition of herbivores?
feed on plants only.
Definition of decomposers?
feed on dead organic matter.
Definition of secondary consumers?
feed on primary consumers.
Definition of carnivores?
feed on meat only.
Definition of tertiary consumers?
feed on secondary consumers.
Definition of omnivores?
feed on both plants and animals.
Name an example of an omnivore?
human/bear/badger
Definition of a food chain?
a sequence of organisms in which one is eaten by the next organism of the food chain.
Definition of a trophic level?
is a feeding stage in the food train.
Definition of trophic?
feeding or nutrition.
Who do producers always occupy?
1st trophic level.
Who do primary consumers occupy?
2nd trophic level.
Why is the food chain limited?
as low amount of energy passed on/lost.
What is a food web and what’s is its function?
consists of two or more food chains that are interlinked. it shows many interrelationships that exist in an ecosystem.
What does a pyramid of numbers represent?
the organism number at each trophic level in a food chain.
As you move up the food chain, the number of organisms at each trophic level?
decreases.
As you move up the food chain, the size of the individual?
increases.
What is a normal pyramid?
the numbers of organisms decline going up the pyramid due to energy loss between trophic levels.
What’s an inverted pyramid?
numbers of organisms don’t always get smaller going up the pyramid which gives rise to an inverted pyramid.
Definition of biomass?
total weight of the organisms.
Give three limitations of pyramid of numbers?
- they can’t always be drawn to scale due to the numbers of organisms being so large.
- they do not always account for the size of the organisms.
- size of some populations can’t be estimated.
Name the four factors that control population size?
- competition
- predation
- parasitism
- symbiosis
What is meant by competition?
when organisms struggle for a scarce resource.
Give an example for plants and animals in competition?
plants compete for food/space/water/light.
animals compete for food/shelter/mates/space.
What does intra-specific competition mean? Give an example.
takes place between members of the same species.
Eg: two blackbirds fighting for territory.
Name the two types of competition?
contest competition and scramble competition.
What does contest competition mean?
Give an eg.
struggle for a resource with one winner
Eg: fighting for territory, food, mate.
What does scramble competition mean?
Give an eg.
Struggle for a resource and all get some.
Eg: plant competing for light and space.
Give two benefits of competition?
ensures evolution and species are maintained.
Discuss an adaptation of organisms to survive competition
a butterfly and caterpillar are the same species but avoid competition as they have different mouth parts. butterflies feed on nectar while caterpillars feed on leaves.
What is meant by predation?
the hunting, killing and eating of another organism.
Definition of a predator? Give eg
an organism that hunts, kills and eats another organism. eg: fox
Definition of prey?
an organism that is eaten by a predator. eg: rabbit.
What are some predator adaptations?
excellent eyesight, night vision, good sense of smell, fast.
What are some prey adaptations? Give an eg and discuss.
good senses, camouflage. eg: rabbit has long ears to hear, strong hind legs and fast.
What are some plant adaptations? Give an eg.
nettles have a sting to protect themselves from predators, flowers are bright colours to attract insects for pollination, wild garlic has a strong odour.
Give four factors that affect human populations?
- war increases the death rate.
- famine increases the death rate.
- contraception reduces the birth rate.
- disease increases the death rate.
What is meant by parasitism?
Relationship in which an organism lives on/in a second species feeding on it and causing harm
What’s a parasite?
a living organism that lives with and feeds off another organism causing harm.
What’s a host? Give an eg.
a living organism that is fed on and harmed by another organism that lives with it. eg: fleas on a dog.
Name the three types of parasites?
endoparasites, exoparasites, obligate parasites.
What’s an endoparasite? Give an eg.
live on the inside of the host’s body causing harm. eg: tapeworm in the human small intestines.
What’s an exoparasite? Give an eg.
live on the outside of the host’s body. eg: fleas on a dog.
What’s an obligate parasite?
require a host to reproduce.
What is the role of parasites?
they control populations of the organism that they feed on.
What’s mutualism?
is another form of symbiosis where both organisms benefit.
Environmental factors affecting organisms?
abiotic factors
biotic factors
climatic factors
edaphic factors
Suns energy is stored by plants in the?
Chemical bonds
Most of energy is lost in the form of?
Heat
Roughly what % of heat is passed on to other organisms?
10%
Feeding represents a flow of?
Energy
Definition of detritus feeders?
Feed on small parts of dead and decomposing animals like mussels.
Primary consumers include? Name 3
Herbivores
Decomposers
Detritus feeders
Secondary consumers include? Name 3
Carnivores, scavengers, omnivores
Give example of a food chain.
Dandelion - butterfly - thrush - hawk
Grass - rabbit - fox
Whats nutrient recycling?
way in which elements are exchanged between living and non-living components of an ecosystem.
Whats the function of the nitrogen cycle?
take nitrogen from air and make it available for use by living things.
Whats nitrogen fixation?
nitrogen to usable form.
what’s nitrification?
conversion of ammonia and ammonium compounds to nitrite and then to nitrate.
Whats denitrification?
conversion of nitrates to nitrogen gas.
Where can nitrogen-fixing bacteria be found?
free in the soil.
Nitrogen fixation is a ___ process?
anaerobic
Nitrogen fixation is carried out by?
volcanic action, lightning, industrial processes and some bacteria.
Bacteria being chemosynthetic means?
make own food using energy from chemical reactions.
Name 4 bacteria types and functions in nitrogen cycle.
nitrogen-fixing bacteria, converts atmospheric nitrogen to nitrates.
bacteria of decomposers, convert nitrogen waste to ammonia.
nitrifying bacteria, convert ammonia to nitrates.
denitrifying bacteria, convert nitrates to nitrogen gas.
Three ways humans affect ecosystems?
pollution, conservation and waste management.
Definition of pollution?
any harmful addition to the environment.
Name and explain 3 types of pollution.
domestic: household wastes.
agricultural: includes use of sprays to control pests/weeds, overuse of fertilisers.
industrial: smoke that causes acid rain and wastes affecting streams, rivers, lakes.
What are pollutants?
harmful additions to the environment.
CFC stands for? Whats it used in?
chlorofluorocarbons, styrofoam
Whats conservation?
protection/management of organisms/environment
2 benefits of conservation?
prevents organisms from becoming extinct.
maintains biodiversity.
Conservation for fisheries?
large mesh size nets
restocking
return young fish
4 problems with waste disposal?
- decaying waste produces metheyne, a greenhouse gas contributing to climate change.
- toxic chemicals released can easily be washed out and enter drinking water supplies.
- nutrients released from waste can affect water supplies, lead to death of plants and animals.
- incinerators burn waste at high temperatures, fear of poisonous gases being released during process.
Give three R’s for control of waste production.
reduce
reuse
recycle
What does recycle mean?
return elements to the environment is it can be reused.
Whats a population?
comprises of all the members of a species living in an area.
Name 4 factors that control populations.
competition,
predation,
parasitism,
symbiosis
Whats inter-specific competition?
occurs between members of different species. Eg: blackbirds and thrushes for insects.
Consequence of competition?
the number of organisms is reduced.
What do plants, and animals compete for?
plants = space, light, water, minerals/
animals = food, water, shelter, territory and reproductive rights.
What does ‘fittest’ mean?
best suited to its environment
Scramble competition tends to?
reduce numbers in a population.
Name ways organisms avoid competition.
feeding habits, camouflaged, protective coats, alterations to mouth parts.
Example of a predator and prey?
Hawks and mice
Whats a predator?
organism that hunts, kills and eats another organism
What is prey?
the organism that is eaten by the predator.
Definition of symbiosis?
relationship between species involving benefit.
Another form of symbiosis is?
mutualism
Whats mutualism?
both organisms benefit from the association
Predator-prey relationships allow?
allow population control
Explain how predator-prey relationship increases and decreases.
increase due to food (prey) availability
decreases due to lack of food (prey)
Explain how the number and time on predator-prey relationship changes.
lower number due to loss of energy or reference to size (predators usually bigger)
delay in increase in time due to time taken to breed
Name 4 factors affecting human population numbers.
war, famine, contraception, disease
How does war affect human population?
high death rate, decrease in population.
How does famine affect human population?
high death rate, decrease in population.
How does contraception affect human population?
low birth rate, decrease in population.
How does disease affect human population?
high death rate, decrease in population.
