Ecology. Flashcards
What is an ecosystem?
An ecosystem is all the organisms living in a habitat and the non-living parts of a habitat.
What are the different levels of organisation in an ecosystem?
-Individual organisms
-Populations-groups of individuals of the same species.
-Communities-made up of many populations living together.
What do plants/animals compete with each other for?
Light, space, water and mineral ions from the soil. Animals often compete with each other for food, mates and territory.
What is interdependence?
Relying on each other. Within a community, each species depends on other species for food, shelter etc. If one species is removed it can affect the whole community. This is called interdependence.
What are the abiotic (non-living) factors which can affect a community?
- light intensity
- temperature
- moisture levels
- soil pH and mineral content
- wind intensity and direction
- carbon dioxide levels for plants
- oxygen levels for aquatic animals.
What are the biotic (living) factors which can affect a community?
- availability of food
- new predators arriving
- new pathogens
- one species outcompeting another so the numbers are no longer sufficient to breed.
What type of adaptations could animals have?
Structural, behavioural or functional.
What are extremophiles?
Organisms that live in environments that are very extreme, such as at high temperatures, pressures, or salt concentrations. Bacteria living in deep sea vents are
extremophiles.
(RP) Investigating the population size of a common species in a habitat.
1)Place a quadrat on the ground at random.
2) Count the number of individual plants of one species in the quadrant.
3) Repeat many times and calculate a mean.
4) Work out the mean in 1m2.
5) Measure the are of the whole habitat and multiply the number of plants in 1m2 by the whole area.
How can you check how plants are spread/distributed in a habitat?
1)Strech a long tape, called a transect line, across the area.
2) Place a quadrat down at regular intervals along the line.
3) Count the plants in the quadrat each time.
What is dead material broken down by?
Decomposers.
What conditions are required for decomposers to break down dead waste?
-Oxygen.
-Moisture.
-A suitable temperature.
- A suitable PH.
If waste is broken down in anaerobic conditions then what is produced?
Methane gas.
(RP) Investigate the effect of temperature on the rate of decay of fresh milk by measuring pH change.
1) Take a sample of fresh milk.
2) Place in a beaker and cover.
3) Keep warm/at room temp.
4) Measure the pH of the milk at regular intervals over several days.
What does the carbon cycle do?
Returns carbon from organisms to the atmosphere as carbon dioxide to be used by plants in photosynthesis.
What does the water cycle do?
Provides fresh water for plants and animals on land
before draining into the seas. Water is continuously evaporated and precipitated.