Topic 9- Ecosystems And Material Cycles Flashcards
Abiotic factor
Non- living conditions which can influence where plants and animals live./ the distribution of organisms
Abiotic factors examples
Sunlight
Wind
Temperature
Biomass pyramid
Producer at the bottom, consumer at the top
Size of trophic level depends on mass
How is energy lost between each trophic level
The organism could lose energy before it’s eaten (by running)
The organism secretes waste
Not all of the organism is eaten (bones).
Population
Group of organisms that are of the same species
Community
Different populations interacting with each other
Habitat
Where the organisms live. Environment and organisms affect habitat.
Interdependence
Organisms within a population and in different populations rely on each other for resources (mating within a population)
(Food different populations)
Abundance
A measure of how common something is in an area (it’s population size)
How to estimate population size
How to calculate population size
By taking samples using a quadrat which is placed randomly in the area multiple time (and a mean is calculated).
Population size= number of organisms in all quadrats times (total size of area where an organism lives) over (total area of quadrats)
Name the types of animals in a food web in order.
Producer Primary consumer/ herbivore Secondary consumer/ carnivore/ predator Tertiary consumer/ carnivore/ predator Top predator
How does a belt transect work
Used to measure the effect of abiotic factors on the distribution of organisms.
Quadrats are placed along a line in a habitat and the abundance (population) of organisms is measured as well as the abiotic factors in each quadrat position.
Changes in abundance show which abiotic factor has the greatest effect on an organism.
What are pollutants?
What are results in human pollutants?
Substances that can cause harm in the environment.
These can poison or cause harm to organisms (plastic bags being eaten by fish)
Biotic factors
Organisms in an ecosystem that affect other organisms
Example of biotic factors
In Yellowstone park, grey wolves were the main predator of elk until they died out. This lead to an increase in the number of elk and therefore the overgrazing of many tree species. This lead to a decrease in other herbivores who didn’t have enough food. The number of coyotes increased because there was less competition from wolves for elk.
When wolves were reintroduced it reduced the numbers of elk which increased the numbers of other herbivores (beavers). The beavers built dams creating large pools which allowed new species to grow which increased biodiversity.
Parasitism
A feeding relationship in which one organism (parasite) benefits by feeding off a host organism, causing harm to the host. The parasite lives in or on a host.
How are tape worms adapted
Hookers and suckers attach worms head to the hosts intestine wall.
Segments contain male and female sex organs so fertilisation can occur.
Flattened body allows absorption of nutrients over whole surface without need for digestive or circulatory systems.
How are lice adapted
Sharp mouthparts pierce skin and suck blood.
Sharp claws grip onto hair and skin.
Eggs are glued to hairs to prevent them falling off.
Mutualistic relationships
When organisms that live together both benefit from the relationship.
E.g. flowers need insects for pollination.
Insects need flowers for nectar used for food.
Eg. Mutualistic relationship
Coral polyps form relationship with single celled algae. The algae can live in the water surrounding corals but are protected inside a polyp. The algae photosynthesise and share food they make with the coral.
Eutrophication
Addition of more nutrients to an ecosystem than it normally has.
E.g. too much fertiliser added to a field. Fertiliser helps crops grow but also increase growth of other plants and algae.
Steps of how eutrophication can affect an ecosystem
Fertiliser added
Rain washes fertiliser off + nitrates and phosphates dissolve in water.
Nitrates and phosphates not taken up by plants washed into stream.
The high concentrations of nitrates and phosphates in water encourage algae to grow rapidly.
Surface plants block sunlight so plants in water die + stop producing oxygen.
Bacteria that break down dead materials increase and use up oxygen. So concentration of oxygen in the water decreases.
Water cycle steps
Rivers flow into lakes + eventually the water returns to ocean.
Groundwater (water that moves through soil and rock).
As air rises it cools, so water vapour in it condenses to form clouds.
As water droplets get too heavy + large they fall as rain or snow.
Desalination
E.g.
Obtaining fresh water from sea or salty water. (Distillation- water evaporates + condenses + collected)
