Ecology Flashcards
Levels of organization in ecology
Cell, Tissue, Organ, Organism, Population, Community, Ecosystem, Biome, Biosphere.
What is population?
- A group of individuals in a particular area that interbreed and therefore share the same gene pool.
- Like a subset of a species, will interbreed due to close location.
- Evolution is seen at this level as individuals and their offspring have changing genotypes and phenotypes.
Exponential growth
Growth occurs exponentially until it can no longer sustain that rate, and it stabilizes.
Carrying capacity
Max population size an environment can sustain. Can change if an environment changes (damaged food source, etc). Predators affect the carrying capacity of an environment.
What is a community?
Group of populations that live in a particular environment. Members of the same community are members of the same ecosystem.
Niche
The way an organism lives in its environment (type of food it eats, where it hunts).If 2 populations have the same niche, there will be a lot of competition, and the losing population will usually evolve to survive.
Predation
When one organism eats another. The organism eating is the predator, but the organism that is eaten doesn’t always die. For example, leaves.
Coevolution
The prey evolves to escape the predator, then the predator evolves to better hunt the prey.
The food chain
- Starts with primary producers. Photosynthetic, usually plants. Highest amount of species here.
- Primary consumers- herbivores that eat the primary producers.
- Secondary consumers- omnivores
- Tertiary consumers- carnivores
Decomposers
Break down dead bodies. Bacteria and fungi.
Scavengers
Eat the waste and remains of dead organisms. Vultures, worms.
How does a food web work?
Arrows show who feeds who.
The 10% rule
There is more energy available at the bottom of the pyramid than at the top. Only 10% of energy is transferred from one level to the next, because most of the energy is used to power the prey.
Ecological Succession
Gradual change in a community over time. Each new community coexists with the previous one. Lichen is first to colonize barren rock. The final community would be deciduous trees.
Pioneer organisms
First to arrive in the area. Other organisms arrive as they are attracted by the first.