Ecology Flashcards
What is meant by the term ‘habitat’?
the place where an organism lives
What is meant by the term ‘population’?
all the organisms of one species living in a habitat
What is meant by the term ‘Community’?
The populations of different species living in a habitat
What is meant by the term ‘abiotic factors’?
Non-living factors of the environment
What is meant by the term ‘biotic factors’?
living factors of the environment
What is meant by the term ‘ecosystem’?
the interaction of a community of living organisms with abiotic parts of their environment
What do plants compete for?
light, space, water, mineral ions
What do animals compete for?
territory, food, water, mates
True of false: No change in any environment can have a knock-on effect.
False, any change in any environment can have a knock-on effect
What are stable communities?
when all of the species and environmental factors are in balance so that the population sizes are roughly constant
What two changes in abiotic factors could affect plant populations?
- A decrease in light intensity, temperature or CO2 concentration would decrease the rate of photosynthesis. This could affect plant growth and cause a decrease in population size
- A decrease in mineral content of the soil could cause nutrient deficiencies, affecting plant growth
What is interdependence?
In a community, each species depends on other species for things such as food, shelter, pollination and seed dispersal
What biotic factors may affect organisms in an ecosystem?
- New predators
- Competition
- New pathogens
- Availability of food
Complete the sentence: Adaptations allow organisms to __________.
survive
What are the three types of adaptations?
Structural
Behavioural
Functional
What are structural adaptations?
Features of an organism’s body structure.
E.g.
- camouflage fur/skin
- thick skin to trap heat
- thin layer of fat to reduce heat
- surface area to volume ratio
What are behavioural adaptations?
The way organisms behave
E.g.
- many species migrate in response to climates changing throughout the year
What are functional adaptations?
Adaptations on the inside of an organism’s body that can be related to processes such as reproduction and metabolism.
E.g.
- animals that conserve water produce little sweat and small amounts of urine
- some animals hibernate and lower their metabolism to conserve energy
Why do microorganisms have a huge variety of adaptations?
so that they can live in a wide range of environments
What are microorganisms that are adapted to live in very extreme conditions called?
extremophiles
What do food chains show?
What is eaten by what in an ecosystem
What do food chains always start with?
A producer
What are producers?
Organisms that make their own food using energy from the Sun.
They are often green plants or algae that make glucose by photosynthesis.
What is glucose used to make in plants?
Other biological molecules in the plant
What is biomass?
The mass of living material
When is energy transferred through living organisms in an ecosystem?
When organisms eat other organisms
What are producers eaten by?
Primary consumers
What are primary consumers eaten by?
Secondary consumers
What are secondary consumers eaten by?
Tertiary consumers
What is the population of any species usually limited by?
The amount of food available
If the population of the prey increases, what else will increase?
The population of the predators
As the population of predators increases, what will decrease?
The number of prey
True or false – Predator-prey
cycles are always out of phase with each other.
True
Why are predator-prey cycles always out of phase with each other?
It takes a while for one population to respond to changes in the other population.
What does environmental variation affect?
The distribution of organisms
What is the distribution of an organism?
Where an organism is found
What are the two ways to study the distribution of an organism?
- Measure how common an organism is into sample areas and compare them
- Study how the distribution changes across an area (by placing quadrat along a transect)
What did the two ways to study the distribution of an organism give?
Quantitative data
Describe how a quadrat can be used to study the distribution of small organisms.
- Use two 10m tape measures and place them perpendicular to each other at one end. Divide the area into a grid.
- Use a random number generator to pick coordinates.
- Place the 1 m² quadrat at the coordinates and count all the organisms within the quadrat.
- Repeat steps 2 and 3 as many times as you can.
- Work out the main number of organisms per quadrat within the first sample area.
- Calculate the population size of an organism by multiplying the mean by the total area of the habitat.
- Repeat in a second sample area and then finally compare the two population sizes.
Describe how a transect can be used to study the distribution of organisms.
- Mark out a line in the area you want to study with a 10m tape measure.
- Collect data along the line by using a quadrat at regular intervals.
- Compare the number of organisms in each quadrat.
Describe how you can estimate the percentage cover of a quadrat.
- Count the number of squares covered by organism A.
- Make this into a percentage by dividing the number of squares covered by the organism by the total number of squares in the quadrat then multiply the result by 100.
- Do the same for organism B.
What are three environmental changes that affect the distribution of organisms?
- Temperature.
- Availability of water.
- Composition of atmospheric gases.
How can temperature affect the distribution of organisms?
A rise in average temperature could cause species to migrate to other areas.
How can availability of water affect the distribution of organisms?
The distribution of some animal and plants species change between the wet and dry seasons.
How can the composition of atmosphere gases affect the distribution of organisms?
In areas of high air pollution, some species cannot grow or the distribution of species changes.
What can environmental changes be caused by?
Seasonal factors
Geographic factors
Human interaction
Global warming
What is the water cycle?
How water is endlessly recycled.
Describe the process of the water cycle.
- Energy from the Sun makes water evaporate from the land and see turning it into water vapour water also operates by transpiration.
- Water vapour is carried upwards. When it gets higher up, it cools down and condenses to form clouds.
- What a fools from clouds as precipitation onto land where it provides freshwater for plants and animals.
- It then drains into the sea before the whole process starts again.
What are the four key terms involved in the water cycle?
Evaporation
Transpiration
Condensation
Precipitation
What are elements cycled back to the start of the food chain by?
Decay
How is biomass returned to the environment?
In waste products when the organisms die and decay
How is biomass returned to the environment?
In waste products when the organisms die and decay
What conditions increase the rate of decay?
Warm, moist aerobic condition because microorganisms are more active in these conditions.
What is the constant cycling of carbon called?
The carbon cycle
What is carbon dioxide removed from the atmosphere by?
Green plants and algae during photosynthesis
What is carbon dioxide removed from the atmosphere by?
Green plants and algae during photosynthesis
When the plants and algae are eaten by animals, what becomes a part of the fat and proteins in the bodies?
Carbon
What are detritus feeders?
Animals that feed on the remains of animals or plants
What gas does respiration release?
Carbon dioxide
What is animal waste broken down by?
Detritus feeders and microorganisms
What does the combustion of wood and fossil fossil fuels release?
Carbon dioxide
What is compost?
Decomposed organic matter that is used as a natural fertiliser for crops and garden plants
What can produce compost?
Decomposition
What is the process of decay also called?
Decomposition