Ecology Flashcards
All about organisms, the environment they live in, and how the two interact.
Habitat
The place where an organism lives.
Population
All the organisms of one species living in a habitat.
Community
The populations of different species living in a habitat.
Abiotic factors
Non-living factors of the environment.
Biotic factors
Living factors of the environment.
Ecosystem
The interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment.
Competition
Plants compete for light, space, water, and mineral ions.
Animals compete or food, mates, and territory.
Why do organisms need resources from the environment/ surroundings and from other organisms?
-To survive
-To reproduce
What is a stable community?
A community where all the species and environmental factors are in
balance so that population sizes remain fairly constant.
What things may different species depend on each other for within a community?
-food
-shelter
-pollination
-seed dispersal
What makes an ecosystem interdependent?
Different species depending on each other within a community.
In an interdependent ecosystem, what happens if a major change in the ecosystem occurs? (e.g. the removal of one species)
The affects can be far-reaching, affecting the whole community.
Why is it a problem that food webs are complex?
Knock-on effects of a change to one part of the ecosystem can be difficult to predict accurately.
What are the different levels of organisation in an ecosystem?
-Individual organisms (plants/animals)
-Populations
-Communities
-Ecosystems
Give an example of a stable community.
-Tropical rainforests
-Ancient oak woodlands
What would the loss of a primary consumer mean for other primary consumers?
Less competition for producers (name a specific one), so population will increase. (initially).
But also more likely to be eaten by predators so population will decrease.
What would the loss of a primary consumer mean for secondary consumers?
Less food so population will decrease.
What would the loss of a primary consumer mean for tertiary consumers?
Less food (if pops of secondary consumers decrease [name them]) so population will decrease.
How can feeding relationships within a community be represented?
-food chains
-food webs
What do food chains begin with?
A producer which synthesises molecules.
What are producers? (usually)
Green plant and algae which make glucose by photosynthesis.
What are the producers of biomass for life on Earth?
Photosynthetic organisms.
Predators
Consumers that kill and eat other animals.
Prey
Consumers which are eaten by predators.
In a stable community, what happens to the numbers of predators and prey?
The numbers rise and fall in cycles.
When asked to describe data, what must we do?
Be explicit and say what we see.
What are producers eaten by?
Primary consumers
What are primary consumers eaten by?
Secondary consumers
What are secondary consumers eaten by?
Tertiary consumers.
What can food chains be divided into?
Trophic levels.
What can trophic levels be represented by?
Numbers, starting at level 1 with
plants and algae.
Further trophic levels are numbered subsequently according to how far the organism is along the food chain.
Trophic level 1
Producers - Plants and algae that make their own food.
Trophic level 2
Primary consumers - Herbivores that eat plants/algae.
Trophic level 3
Secondary consumers - Carnivores that eat herbivores.
Trophic level 4
Tertiary consumers - Carnivores that eat other carnivores.
What are apex predators?
Carnivores with no predators (aka. organisms at the top of a food chain).
What are trophic levels?
The different stages of a food chain, consisting of one or more organisms that perform a specific role in it.
Why are there usually only four or five trophic levels in a food chain?
A lot of energy is lost from the food chain at each trophic level.
List the abiotic 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 can cause a change in the environment?
-An increase or decrease in an abiotic factor e.g. an increase in temperature
-The introduction of a new biotic factor e.g. a new predator or pathogen.
What can changes in the environment affect?
-The size of populations in a community.
-This means that they can also affect the population sizes of other organisms that depend on them (abiotic).
-They have knock-on effects because of interdependence (biotic).
What is the effect of a decrease in light intensity, temperature, or carbon dioxide?
-Decreases the rate of photosynthesis in plant species
-This affects plant growth and could cause a decrease in the population size
-Animal species which depend on the plants for food may also be affected
What is the effect of a decrease in the mineral content of the soil? (e.g. a lack of nitrates)
-Causes nutrient deficiencies
-This affects plant growth and could cause a decrease in the population size
-Animal species which depend on the plants for food may also be affected
List the biotic factors which can affect a community.
- availability of food
- new predators arriving
- new pathogens
- competition - one species outcompeting another so the numbers are too low to breed.
Why is the population of red squirrels decreasing?
Red and Grey squirrels live in the same habitat and eat the same food.
Grey squirrels outcompete the red squirrels.
Adaptations
A feature an organism has that allows it to survive in its ecosystem.
What are the three types of adaptation?
-Structural
-Functional
-Behavioural
What is a structural adaptation?
Features of an organism’s body structure that allows it to survive in it’s ecosystem.
What is a behavioural adaptation?
Ways that an organism behaves that allows it to survive in it’s ecosystem.
What is a functional adaptation?
Things that go on inside an organism’s body related to processes like reproduction and metabolism that allows it to survive in it’s ecosystem.
Extremophiles
Organisms that are adapted to live in environments that are very extreme, such as at high temperature, pressure, or salt concentration.