Adaptations, Interdependence & Competition Flashcards
All 27 cards in this deck
What is an ecosystem?
The interaction of a community of living (biotic) organisms with the non-living (abiotic) parts of their environment.
What is a community in ecology?
All the populations of different species living in the same habitat, interacting with each other.
List the levels of organisation in an ecosystem from smallest to largest.
Individual organism → population → community → ecosystem.
What is interdependence in a community?
Species depend on each other for things like food, shelter, pollination and seed dispersal, so removing one species can affect the whole community.
What is a stable community?
One where all the species and environmental factors are in balance, so population sizes remain fairly constant.
True or false? A habitat and a population mean the same thing.
False. A habitat is the place where an organism lives; a population is all the organisms of one species living in that habitat.
What are abiotic factors?
The non-living factors of the environment that can affect a community, e.g. temperature.
List the abiotic factors named in the specification that 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.
Which abiotic factor is especially important for aquatic animals such as fish?
Dissolved oxygen levels in the water.
True or false? Shading by a building is an abiotic factor.
True. Shading reduces light intensity, and light intensity is a non-living factor.
How does a fall in light intensity affect plants in a community?
Less photosynthesis, so plants grow more slowly and fewer survive, reducing food and shelter for animals.
What are the steps to explain the effect of a change in an abiotic factor using data?
e.g. a graph shows fewer plants where the soil is more acidic
- State the trend from the data: plant numbers fall as soil pH falls.
- Name the abiotic factor: soil pH.
- Link to survival: acidic soil reduces mineral ion uptake, so plants grow less well and the population falls.
True or false? Two genetically identical plants in the same garden must grow to the same height.
False. Differences in abiotic factors such as light, water, mineral ions and soil pH can make them grow differently.
What are biotic factors?
Living factors of the environment that can affect a community, e.g. predators.
List the four biotic factors named in the specification that can affect a community.
Availability of food, new predators arriving, new pathogens, and one species outcompeting another.
What three resources do animals often compete for?
Food, mates and territory.
How can a new predator arriving affect a community?
Prey are eaten, so prey numbers fall rapidly; species that depend on that prey are also affected.
What happens when one species outcompetes another for a resource?
The numbers of the outcompeted species fall until they are no longer sufficient to breed, and it may die out from that habitat.
True or false? Rabbits eating plants is a biotic factor, but nitrates in the soil are abiotic.
True. Rabbits are living organisms; nitrate mineral ions are non-living.
Why does an increase in the diversity of trees in a rainforest increase animal diversity?
More or different types of food are available, and more or different habitats and nest sites are available.
What is an adaptation?
A feature that enables an organism to survive in the conditions in which it normally lives.
What are the three types of adaptation?
Structural, behavioural and functional.
What is a behavioural adaptation?
e.g. a bird migrating in winter
An adaptation involving the way an organism acts; migrating avoids cold conditions and lack of food.
What is a functional adaptation?
e.g. a camel producing very concentrated urine
An adaptation involving processes inside the body, such as reproduction and metabolism; concentrated urine conserves water in the desert.
What are extremophiles?
Organisms that live in very extreme environments, such as high temperature, high pressure or high salt concentration.
Give the example of extremophiles named in the specification.
Bacteria living in deep sea vents, which tolerate high temperature and high pressure.
True or false? Thick fur on an Arctic fox is a structural adaptation.
True. It is a physical feature of the body, so it is structural.