Ecology Flashcards
ecology
is the study of how organisms interact with each other and their environment
what is the environment of an organism
external factors that influence it
population
the members of the same species living in an area
habitat
place where an organism live
community
all the different populations in an area
biosphere
part of the planet where life exists
biotic factors
living factors
give an example of a biotic factor
competition
available quantity of food
abiotic factors
non living factors
give an example of abiotic factor
climatic factors ie weather: more rain= more water supports more life
edaphic factors ie soil pH: affects growth of plants
edaphic factors
anything to do with soil
aquatic environmental factors
light
currents
wave action
salt content
oxygen concentration
what is our primary source of energy
the sun
what form of energy enters the food chain
light energy
what is needed to maintain ecosystems
constant input of energy
ecosystem
a group of clearly distinguished organisms that interact with their environment as a unit
what is an example of an ecosystem
dessert
what form of energy leaves the food chain/our bodies
heat
energy flow
the pathway of energy transfer from one organism to the next in an ecosystem due to feeding eg along a food chain
what are primary producers
green plants
what are primary consumers
herbivores
what are secondary consumers
carnivores
what are tertiary consumers
top carnivores
producers
organisms that carry out photosynthesis
consumers
organisms that take in food from other organisms
food chain
a sequence of organisms in which one is eaten by the next one
give an example of a food chain
dandeline—-> butterfly—->thrush—->hawk
grass—–> rabbit—–>fox
buttercup—->caterpillar—->blackbird—-> fox
trophic level
feeding stage of a food chain
who occupies the first trophic level
producers
who occupies the second trophic level
primary consumers
why are food chains so short?
only about 10% of energy at each trophic level is passed onto the next trophic level
this means the amount of energy decreases significantly from one trophic level to the next which limits the no of trophic levels of any food chain to 4/5
how much energy is lost and passed on in each food chain
90% lost
10% passed on
food web
consists of 2 or more interlinked food chains
what is a pyramid of numbers
a diagram that represents the number of organisms at each trophic level in a food chain
limitations if a pyramid of numbers
the size of organisms is not considered in a pyramid of numbers eg. one rose bush can support 1000s of greenfly
parasitic food chains not taken into account: numerous parasites live on one host.
BOTH RESULT IN A DISTORTED PYRAM ID OF NUMBERS
methods of population control
competition
predation
parasitism
symbiosis
competition
organisms actively struggling for a resource that is in short supply
what is the consequence of competition
no of organisms reduced
intra specific competition
between members of the same species
interspecific competition
between members of different species
contest competition
physical contest between 2 individual organisms where only organisms gets all the resource
what is an example of contest competition
deer claiming territory for nesting, feeding, reproduction and area is defended by male
scramble competition
struggle between a no of organisms where all the organisms receive a small amount of the resource
give an example of scramble competition
overcrowding of seedlings where all receive some light but not enough to grow at full potential
predation
the catching killing and eating of another organism
predator
organism who catches kills and eats other organisms eg. fox
give 2 adaptations that improve efficiency of predators
hawks have good eyesight which makes it easier to locate prey
ladybirds have strong mouth parts which allows them to eat aphids
prey
organism that is eaten by predator
adaptations of prey to avoid being eaten
mice have a flexible skeleton to hide and flee
ladybirds have an acidic taste which is unpalatable to predators
parasite
an organism that lives on/in a live host obtaining its food from the host and causing harm to it.
exoparasite
live on the host eg fleas on a dog
endoparasite
lives inside a host- potato blight fungus in potatoes
symbiosis
when 2 organisms of different species live in close proximation where at least 1 organism benefits
mutualism
2 organisms of different species live in close proximity where both organisms benefit
example of mutualism
bacteria in the intestine get food and shelter from the intestine and the intestine gets vitamin B + K
explain the fluctuation of the predator prey relationship graph
as prey numbers increase predator numbers increase as they have more food to eat
the rising no of predators causes decrease in prey numbers as they are preyed on
as prey no. decreases the no of predators soon declines too as they have less food source
why is there a lag time in the predator prey relationship graph
as the no of prey raises the no of predators need time to adjust and increase their no
draw the predator prey relationship graph
y axis= size (no of organism)
x= time
prey has to be higher than predators
prey starts much higher
label predator + prey lines
factors affecting predator prey relationships
availability
concealment
movement of predators
they control population size
niche
functional role of an organism in its community
factors affecting human population
war
famine
contraception
disease
explain war in terms of factors affecting human population
increased death, reduces population, followed by baby boom
explain famine in terms of factors affecting human population
malnutrition and death, reduces population, problems with food distribution
explain contraception in terms of factors affecting human population
more availability in western countries average family size is decreased
explain disease in terms of factors affecting human population
nowadays there are more vaccines and improvements in medicine, longer life expectancies less disease related deaths
what is the function of nutrient recycling
elements can be reused
why do elements need to be reused
because we have a finite supply of resources of earth
nutrient recycling
elements exchanging between living and non living components of an ecosystem
what are the organisms involved in the carbon cycle
plants
Animals
fungi + bacteria
what are the processes involved in the carbon cycle
photosynthesis, respiration, decomposition
what is the role of plants in the carbon cycle
remove co2 from environment in photosynthesis return it in respiration
what is the role of animals in the carbon cycle
obtain carbon from eating plants, release carbon in respiration
what is the role of fungi + bacteria in the carbon cycle
return carbon to atmosphere when they decompose dead organisms
why is the concentration of co2 in the atmosphere increasing
burning fossil fuels
destruction of worlds forests
co2 greenhouse gas allows sunrays in but not reflected rays out causing global temp to increase
what are the effects of global warming
ice caps melting + sea levels rising
altered weather patterns
increasing storm effects
fear of gulf stream reversing its direction
function of nitrogen cycle
make nitrogen available for use by organisms
why do organisms need nitrogen
growth and repair
protein
draw + label a diagram of the nitrogen cycle
nitrogen
in air N2
nitrogen fixation ] n denitrification
nitrogen fixing ] [ denitrifying bacteria
bacteria V [
[ ———————-nitrate in soil NO3- ————–]
[ ]
V nitrites (nitrification) (nitrifying bac)
]
plant ———————decomposition ]
] —————————— ammonia
] n
V ]
animal—————-> urea——————————–
explain the nitrogen cycle
high temp in lightning breaks bonds of nitrogen gas
nitrogen fixing bacteria found in legumes convert nitrogen gas to nitrates (nitrogen fixation)
nitrates are absorbed and converted to ammonium salts
plants are eaten by animals passing nitrogen to animals
animals excrete urea in urine which is converted to ammonia
ammonia is converted to nitrites by nitrifying bacteria
denitrifying bacteria converts nitrates into nitrogen gas
what is the role of nitrogen fixing bacteria
convert nitrogen gas to nitrates
what is the role of bacteria/fungi of decay in the nitrogen cycle
convert protein into nitrogen compounds eg ammonium salts
what is the role of nitrifying bacteria
convert nitrogen compounds into nitrites and nitrites into nitrates
what is the role of denitrifying bacteria
converts nitrates in to nitrogen gas
pollutionn
any harmful addition made by humans to a habitat or the environment that leaves it less able to sustain life
what are the 3 areas of pollution
industrial pollution
agricultural pollution
domestic pollution
pollutants
chemicals of human origin that harm the environment
what area of pollution did you study
agricultural
what is the pollutant of agriculture
slurry and fertilizer
what is the source of the pollutant of agriculture
it is washed or leached from land
what are the effects of slurry on a farm
formation of algal blooms and eutrophication which causes fish to die
control measures of spreading slurry on a farm
avoid spreading on wet waterlogged or frozen land
or on a steeply sloping hill
or within 1.5 m of any water course
how does acid rain form
co2 dissolves in rainwater to form carbonic acid
releases other oxides like sulphur dioxide and nitrogen oxide
sulpher dioxide dissolves in rain water to forms sulphuric acid decreasing the pH of rain forming acid rain
what are the impacts of acid rain
reduces soil pH
erodes limestone buildings
how do we control acid rain
reduce the amount of fossil fuels being burnt by switching to a renewable type of energy
usr catalytic converters
in engine exhausts and chimneys of factories
conservation
the wise management and protection of natural resources and the environment
conservation of fish in fisheries
the use of small nets can result in too many young fish being caught
by using larger nets to allow the young to escape, they can mature and reproduce keeping populations strong
what is waste management
is the collection, transportation, processing, recycling or disposal of waste materials produced by human activity in an effort to reduce their effect on human health or local asthetics or amenity
what are the problems with waste disposal
no space in cities for landfills
toxic fumes from incineration
methane gas released which contributes to the greenhouse effect
harmful substances may leak into groundwater supplies
plants and animals are killed through direct poisoning or eutrophiciation
how to minimise waste
reduce, reuse, recycle
how do we minimise waste on a farm
slurry is stored in leak proof pits and only spread on land when it is dry
role of microorganisms in waste disposal on landfill sites
bacteria break down organic waste
role of microorganisms in waste disposal of sewage
small amounts of sewage are treated naturally by bacteria in water
large amounts of sewage have to be treated by sewage treatment plants
sewage treatment
sewage can cause eutrophication of lakes and rivers if released directly into them- this causes fish to die
this is why sewage must be treated
what are the 3 stages of sewage treatment
primary sewage treatment
secondary ()
tertiary ( )
primary sewage treatment
physical: screening large objects by flowing sewage through metal grills
sedimentation of sewage where it is stored in tanks and smaller particles such as grit settle out at the bottom producing sludge which is removed
secondary sewage treatment
biological method : bacteria and fungi are added.
organic matter in sludge and waste water is broken down with the production of methane gas, carbon dioxide and water
at the end of the biological process the waste water is usually treated with chlorine to destroy any remaining microorganisms
tertiary sewage treatment
chemical method: removal of minerals by addition of chemicals that cause the minerals to precipitate out of the waste water
omnivore
eats plants and animals
herbivore
only eats plants
carnivore
only eats animal
where are primary producers found in a pyramid of numbers
at the base
can a parasite be the first member of a food chain
no they are not producers
what are the sources of competition among plants
water
light
nutrients
what are sources of competition among animals
mates, water, shelter, food
why is it necessary for an organism to possess an adaptation to its habitat
to improve an organisms chance at survival
what are the 2 types of adaptation
structural and behavioral
flora
plant life present in an ecosystem
fauna
animal life present in an ecosystem
examples of flora in a grassland
dandelion
grass
clover
nettles
daisies
dock leaves
examples of fauna in grassland
ladybird
caterpillars
butterflies
spiders
slugs
beetles
methods of identification
get an expert to name them for you
use guidebooks, photographs or diagrams
use a key
what is a key
a means of naming organisms by answering a series of questions with alternative answers
adaptations
alteration that improves an organisms chance of survival and reproduction
give an example of a fauna adaptation, refer to the organism the adaptation and the benefit
ladybird
brightly coloured- avoided by predators as birth colours indicate acidic toxins
hawks
sharp talons- catch and kill prey
give an example of a flora adaptation, refer to the organism the adaptation and the benefit
dandelions
seeds have parachutes- easily dispersed
nettles
stinging cells- produce stinging acid to deter consumers
qualitative survey
records the presence or absence of organisms in an ecosystem
quantitative survey
records the numbers or organisms that are present
subjective
A personal judgement as to the number
objective
an independent method of calculating numbers is used
what is the importance of carrying out quantitative and qualitative surveys
- gives an insight into the numbers of a species in an ecosystem as a baseline and later used as a comparison
- detects changes in population numbers which can be linked to pollution levels
- insight into the relationship between different organisms and how their populations depend on each other
what can be used to present info gathered
tables, pie charts, graphs, diagrams, histograms ect.
sources of error in an ecosystem
human error- mistakes in measuring or recording
changing conditions- both natural ie seasons or artificial ie pollution
accidental discoveries
sample size
