2. Ecology Pt4 Flashcards
(26 cards)
Why do organisms have adaptations?
It enables them to survive in the conditions they normally live in
Define habitat?
Where an organism lives
Define population
All the organisms if 1 species living in a habitat
Define community
The populations of different species living in a habitat
Define ecosystem?
The interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of the environment
Define interdependence?
- Where in a community each species depends on other species for things such as food, shelter, pollination & seed dispersal
- if one species is removed it can affect the whole community
What’s a stable community?
It’s where all the species & environment factors are in balance so that population sizes remain fairly constant
To ………….. and ………… organisms require a supply of …………… from their surroundings and from the other living ………….. there
Survive
Reproduce
Materials
Organisms
List 7 abiotic factors which can affect a community?
- Light intensity
- Temperature
- Moisture levels
- Soil pH & mineral content
- Wind intensity & direction
- Carbon dioxide levels for plants
- Oxygen levels for aquatic animals
What are 4 biotic factors that can affect a community?
- Availability of food
- New predators arriving
- New pathogens
- One species outcompeting another so the numbers are no longer sufficient to breed
What eats a producer?
Producers are eaten by primary consumers, which in turn may be eaten by secondary consumers & then tertiary
Why are producers so important?
Because photosynthetic organisms are the producers of biomass for life on earth
How can you find the distribution and abundance of a species?
Transect
Quadrat
What do consumers do?
- ones that kill & eat other animals are predators
- those that are eaten are prey
- in a stable community the number of predators and prey rise and fall in cycles
What do producers do?
- Food chains begin with a producer which synthesises molecules
- usually a green plant or alga which makes glucose by photosynthesis
- they transfer about 1% of the incident energy from light For photosynthesis
How do decomposers work?
- They break down dead plant & animal matter by secreting enzymes into the environment into small soluble food molecules
- Which then diffuse into the microorganisms
What’s found in trophic level 1?
Plans & algae make their own food & are called producers
What’s found in trophic level 2?
Herbivores eat plants/algae & are called primary consumers
What’s found in trophic level 3?
Carnivores that eat herbivores are called secondary consumers
What’s found in trophic level 4?
Carnivores that each other carnivores are called tertiary consumers
Apex predators are carnivores with no predators
Why are they’re usually only 4 or 5 trophic levels?
Because by them too much energy has been lost from the food chain
Define biodiversity?
The variety of all the different species of organism on earth or within an ecosystem
What changes can effect the distribution of animals in an ecosystem?
(Environmental changes) -temperature -availability of water -composition of atmospheric gases (These changes can be seasonal, geographic or caused by human interaction)
What’s food security?
Having enough food to feed a population
