Biology (Unit 1): Organisation & Distribution of Life

What is ecology?

the study of how living things interact with each other and their environment

What is the difference between a biotic and an abiotic factor?

a biotic factor is a living thing or its actions, while an abiotic factor is a non-living part of the environment

Give a few examples of abiotic factors?

things like temperature, sunlight, water, wind, and soil

Give a few examples of biotic factors?

things like predators, prey, plants, and competition between organisms

What are Earth's four spheres?

the atmosphere, biosphere, geosphere, and hydrosphere

What is the atmosphere?

the layer of gases surrounding the Earth

What is the biosphere?

all the living things on Earth and where they exist

What is the geosphere?

the solid rock and land of the Earth

What is the hydrosphere?

all the water on Earth

How do Earth's spheres interact?

they overlap and exchange matter and energy, such as plants using gases from the atmosphere

What is the order of ecological organisation from smallest to largest?

population, community, ecosystem, biome, then biosphere

What is a population?

all the members of one species living in the same area

What is a community?

all the different species living and interacting in an area

What is an ecosystem?

a community of living things together with the abiotic factors around them

What is the key difference between a community and an ecosystem?

a community is only the living things, while an ecosystem also includes the non-living environment

What is a biome?

a large region defined by its climate and the life adapted to it

What is the difference between a biome and an ecosystem?

a biome is a climate-based category containing many ecosystems, rather than a single interacting unit

Why is a biome not just a big ecosystem?

the organisms across a biome do not all interact, whereas interaction is what defines an ecosystem

What splits aquatic ecosystems into two main types?

the salinity, or salt content, of the water

What are the two main types of aquatic ecosystem?

marine (salt water) and freshwater

Which type of aquatic ecosystem covers more of the planet?

marine ecosystems

What is species richness?

the number of different species living in an area

How does species richness change from the equator to the poles?

it is generally highest near the equator and lowest near the poles

Why is species richness higher near the equator?

the warm, wet, stable climate and direct sunlight support more life

Why is it colder near the poles?

sunlight hits at a low angle there, spreading its energy over a larger area

How do temperature and rainfall change as you move away from the equator?

both generally decrease

Why does less rainfall tend to occur in colder regions?

cooler air holds less moisture