Ecological Relationships And Energy Flow Flashcards
What is biodiversity?
Biodiversity is the measure of the number of species in an area
What is a habitat?
The place where an organism lives
What is a population?
The number of one type of organism in an area
What is a community?
The total number of organisms from all the populations in one area
What is an environment?
The factors, both physical (abiotic) and living (biotic), that affect organisms in a habitat
What is an ecosystem?
The community of organisms that are interdependent on each other and the environment in which they live
What are abiot factors? Give some examples
Abiotic factors are non-living factors that affect the distribution of plants and animals. Some examples include :
- Wind which can be measured using anemometers
- Water. Soil moisture levels can be calculated by taking soil samples and weighing the to find their mass, drying them in an oven and then reweighing them. The difference in mass as a percentage of the original mass gives a value for the percentage of water in the soil.
- pH which can be measured using paper
- Light which can be measured using light meters
- Temperature which can be measured using a thermometer
How can the percentage cover of plants be measured?
Using quadrants
What are plants in completion with each other for?
Water, light, space and minerals /nutrients
What are animals in competition with each other for?
Water, food, territory and mates
What are consumers?
Green plants that absorb light and make their own energy through photosynthesis
How is energy lost in a food chain?
Respiration/heat
How does decomposition happen?
Saprophytic bacteria and fungi secrete enzymes into the soil or dead organisms. The enzymes break down the organic material and it is then absorbed by the bacteria or fungi.
What are the optimum conditions for decomposition?
A warm temperature, adequate moisture and a large surface area in the decomposing organism
Which bacteria convert ammonium compounds into nitrates?
Nitrifying
Which bacteria convert nitrogen gas into nitrates and where are they found
Nitrogen fixing bacteria and they are found in the soil and root nodules
Which bacteria convert nitrates into atmospheric nitrogen and where are they mostly found?
Denitrifying bacteria and they are mostly found in waterlogged soils
How can the processes of nitrification and denitrification be accelerated?
Higher temperatures and well aerated soil
How are root hair cells adapted for the uptake of nitrates, other minerals and water?
A large surface area
What happens in eutrophication
- Fertiliser run off increases the level of nitrates in nearby rivers
- Increased nitrates cause increased growth in plants, blocking off light form smaller plants below and making them die
- The dead plants are decomposed by bacteria
- The bacteria use lots of oxygen for respiration which causes the oxygen levels to decrease
- Fish suffocate due to lack of oxygen
