Topic 5 - Ecology and evolution Flashcards
What is a species?
A group of organisms that can interbreed and produce fertile offspring
What is a habitat?
The environment in which a species normally lives or the location of a living organism
What is a population?
A group of organisms of the same species who live in the same area at the same time
What is a community?
A group of populations living and interacting with each other in an area
What is an ecosystem?
A community and its abiotic environment
What is ecology?
The study of the relationships between living organisms and between organisms and their environment
What is an autotroph?
An organism that synthesises its organic molecules from simple inorganic substances
What is a heterotroph?
An organism that obtains organic molecules from other organisms
What is a consumer?
An organism that ingests other organic matter that is living or recently killed
What is a detritivore?
An organism that ingests non-living organic matter
What is a saprotroph?
An organism that lives on or in non-living organic matter, secreting digestive enzymes into it and absorbing the products of digestion
What is a food chain?
A sequence of trophic relationship, where each member in the sequence feeds on the previous one
Give three examples of food chains
- passionflower → heliconius butterly → tegu lizard → jaguar
- carrot plant → carrot fly → flycatcher → sparrowhawk → goshawk
- sea lettuce → marine iguana → galapagos snake → galapagos hawk
What is a food web?
A diagram that shows all the feeding relationships in a community.
What is a trophic level?
The position of an organism in the food chain
(producer → primary consumer → secondary consumer → etc)
What is the initial energy source for almost all communities?
Light
Describe the energy flow in a food chain
Are energy transformations ever 100% efficient?
No
What is a pyramid of energy?
A pyramid that shows the flow of energy from one trophic level to the next in a community
Why is the pyramid of energy pyramidal?
Because energy is lost at each trophic level and less energy remains for the next level
While energy enters and leaves ecosystems, what happens to nutrients?
They must be recycled
What organisms recycle nutrients?
Saprotrophic bacteria and fungi
Draw and label a diagram of the carbon cycle
What has happened to the concentration of atmospheric carbon dioxide?
It has gradually increased
What is meant by the enhanced greenhouse effect?
- Short wavelengths come from the Sun and pass through the atmosphere
- Sunlight warms up the surface of the Earth which emits long-wave radiation
- Greenhouse gases in the atmosphere trap some of the long-wave radiation, causing the earth to be warmer than if the radiation escaped
What have greenhouse gases done to the enhanced greenhouse effect?
They have increased its effect