Ecology Flashcards
(39 cards)
Factors which organisms compete for in a given habitat
Plants - light, space, water and mineral ions(nutrients) from the soil
Animals - Space(territory), food, water and mates
How are organisms adapted to the conditions that they live in
- Features of their body structure e.g. shape or colour - A camel has a large surface area to volume ratio to help them lose heat
- Behaviour - birds migrating to warmer climates
- Functional - Desert animals conserve water by producing very little sweat
Define an ecosystem
The interaction if a community if living organisms with the non living parts of their environments
Define interdependence
This means that all the organisms in an ecosystem are dependent upon each other
What is a stable community
A stable community is one in which the size of the populations of all species remain relatively constant over time
Explain how a change in the abiotic factors would affect a given community
These changes can affect the sizes of population in a community. This means they can also affect the population sizes of other organisms that depend on them. For example, animals depend on plants for food so a decrease in a plant population could affect the animal species in a community.
List abiotic factors
- Moisture levels
- Light intensity
- Temperature
- CO2 levels for plants
- O2 levels for aquatic animals
Explain how a change in the biotic factors would affect a given community
A change in the environment could be the introduction of a new biotic factor .e.g. a new predator or pathogen. These changes can affect the sizes of populations in a community which can have knock on effects because of interdependence.
List biotic factors
- New predators arriving
- Competition
- New pathogens
- Availability of food
Describe an extremophile
An extremophile is an organism that lives in an extreme environment. An extreme environment is one in which most organisms would find it difficult or impossible to survive.
What is a producer
Starting point of a food chain
Called a producer as they make their own food by photosynthesis
What is a primary consumer
Herbivores that eat the plants and algae
What is a secondary consumer
Carnivores that eat the primary consumers
What is a tertiary consumer
Carnivores that eat other carnivores are tertiary. Carnvivore’s that have no predators are at the top of the food chain so they’re always in the highest trophic level are known as apex predators
Explain why, in a stable community, the numbers of predators and prey rise and fall in cycles
The number of predators increases because there are more prey, so there is more food for them to eat. The number of prey reduces because there are more predators, so more get eaten. The number of predators reduces because there is less prey, so less food.
Explain the role of microorganisms in cycling materials through an ecosystem
Microorganisms are responsible for the degradation of organic matter, which controls the release of plant nutrients, but is also important for the maintenance of soil structure and sustainability of soil quality for plant growth.
State factors which affect the rate of decay(biology only)
- Temperature
- Water availability
- Oxygen availability
- Number of Decay organisms
State the role of decomposers
Decomposers secrete enzymes into the environment. The enzymes digest dead animals or plant material into small, soluble molecules, The small soluble food molecules then diffuse back into the decomposer. The decomposer uses the soluble, food molecules for growth and respiration
List the tropic levels
Producers, primary consumers, secondary consumers and tertiary consumers
How much biomass gets transferred to the next level
Approximately 0%
Reasons for the loss of biomass at each level
- Organisms don’t eat every part of the organism that they are consuming ( the bones) so not all the biomass could be passed on
- Organisms don’t absorb all the stuff in the food they ingest. The things they don’t absorb is egested as faeces
- Some of the biomass is converted into other substances that are lost as waste. For example, organisms use a lot of glucose, obtained from the biomass, in respiration to provide energy for movement and keeping warm, rather than to make more biomass. This process produces lots of waste CO2 and water as by products. Urea is another waste substance that is released in urine with water when the proteins in the biomass are broken down.
What is the carbon cycle
1)Carbon enters the atmosphere as carbon dioxide from respiration and combustion.
2)Carbon dioxide is absorbed by producers to make carbohydrates in photosynthesis.
3)Animals feed on plants, passing the carbon compounds along the food chain. Most carbon they consume is exhaled as carbon dioxide during respiration. The animals and plants eventually die.
4)Dead organisms are eaten by decomposers and carbon in their bodies is returned to the atmosphere as carbon dioxide. In some conditions decomposition is blocked. The plant and animal material may then be available as fossil fuel in the future for combustion.
What is the water cycle
Transpiration. We discussed the transpiration stream previously. This works to send water taken in by the roots of the plants back into the atmosphere as water vapour.
Evaporation. Water evaporates, changing state from liquid to gas, from bodies of water, such as lakes and oceans and ponds. Light energy from the sun causes this.
Condensation. After evaporation and transpiration, the water vapour cools, forming liquid clouds.
Transport. When liquid clouds are formed, they can be pushed far distances by wind.
Precipitation. Rain, snow, sleet and hail fall from the clouds into the bodies of water and the land.
Surface runoff. Sometimes, when there is a large amount of precipitation, water runs along the earth to enter bodies of water.
Infiltration. Some water that falls is absorbed into the ground. It can then be stored in aquifers. These are underground, permeable rocks.
What is biodiversity
Biodiversity is a measure of the number of different species, their variety and their genetic diversity in a particular habitat
