B16/17/18 - Ecology Flashcards
ecology
the study of organisms and how they interact with the environment around them
habitat
a place where an organism lives
individual
one organism of a species
population
total number of organisms of one species living in a habitat
define:
community
populations of different species that live in a habitat
ecosystems
a community of interacting organisms and their physical environment
interdependence
organisms in an ecosystem that are dependent on each other
list 3:
common examples of interdependence within an ecosystem
- plants produce food through photosynthesis
- animals eat plants
- animals pollinate plants
- animals eat animals
- animals use biological materials to create shelters
- plants use nutrients from animal droppings
define:
biotic factor
a factor caused by a living organism
define:
abiotic factor
a factor not caused by a living organism
list 3:
abiotic factors that affect a community
- light intensity
- temperature
- humidity
- soil pH and mineral content
- air movement
- availability of oxygen
- availability of carbon dioxide
list 3
biotic factors that affect a community
- availability of food
- new pathogens
- new predators
- interspecific competition (competition between species)
quadrat
a square frame used to sample the population of organisms within the area
quantitative sampling
a technique where several random readings are taken and the mean is found between them
How do you sample a population of daisies with a quadrat?
- find the area of a location and split it into 1m by 1m squares
- use random numbers as coordinates to avoid bias
- sample 10% of the location
- count the number of daisies in each quadrat
- find the mean of all samples that were found
- use the mean to find the estimated amount of daisies in the location
How do you sample a population of daisies with a transect?
- stretch a tape between two points
- use a quadrat to take samples across the line
Why are transects usually used?
To find if there is a biotic or abiotic factor that affects the population of an organism across the transect
What are 2 ways in which animals compete for mates?
- they fight
- they display themselves to gain attention with an adaptation that can make them stand out
list 4:
What do animals compete for?
- water
- food
- territory (space)
- mates
list 4:
What do plants compete for?
- light
- water
- minerals
- space to grow
define:
extremophiles
organisms that survive and reproduce in extreme conditions
give 2 examples of adaptations in extremophiles
- High heat - adapted enzymes that do not denature at high temperatures
- Salty habitat - adapted cytoplasm so water does not leave cells through osmosis
Epiphytes are found in rainforests. What adaptation do they have to help them survive?
They can live high above the ground by taking water and nutrients out of the air.
What are the 3 types of adaptations an animal can have?
- structural - shape, colour
- behavioural - migration, basking in the sun
- functional - antifreeze in cells, metabolism
give 2 adaptations that animals have in cold climates
- smaller the surface area to volume ratio the easier it is to minimise energy dissipating to the surroundings (physical adaptation)
- large layers of insulation, e.g. blubber and fur (physical adaptation)
give 3 adaptations that animals have in hot and dry climates
- functional adaptations in kidneys to produce little urine
- behavioural adaptations to keep cool, walking in the evenings and early mornings
- thinner skin (physical adaptation) dissipate more energy to the surroundings
What are the 2 main problems that animals face in the desert?
- coping with a lack of water
- stopping their body temperature from getting too high or too low
define:
biomass
the mass of organisms
formula:
efficiency of energy transfer between organisms
efficiency = biomass before / biomass after
2 types of biomass
wet biomass - mass of organism incuding water
dry biomass - mass of organism without water
list:
name of each tertiary level
up to 4th
- producer
- primary consumer
- secondary consumer
- tertiary consumer
define:
stable community
a community where species and environmental factors are in balance so that population sizes stay fairly constant
define:
competition
organisms competing for resources
What does a pyramid of biomass show?
The biomass of different trophic levels of a food chain.
define:
decomposers
microorganisms that break down (decompose) organic material
bacteria and fungi
define:
detritivores
consume organic material
fungi and invertebrates
list 3:
energy is lost up tropic levels
- movement
- heat
- reproduciton
name:
the 2 cycles found in nature
the water cycle and the carbon cycle
importance of the water cycle
provides fresh water to organisms on land
importance of the carbon cycle
carbon is vital for organisms, creating structures like proteins and DNA
