Interactions of Living Things

Interactions of Living Things

Ecology 3

Species

• Smallest grouping of living based on characteristics

– Must be able to produce offspring that can reproduce

Population – group of species in an area

Habitat

• Physical location of where organisms live– Different populations can live in same habitat• Grassland• River• Lake

Niche

• Role an organism plays in habitat– No 2 species will fill the same exact niche• Fly decomposes organic matter• Honey bee pollinates flowers• Alaskan wolf controls caribou population

Community

• Group of populations that live in and interact within a particular area– Frogs, bass, snakes in a lake community

Competition

• Organisms struggle with one another and the environment to obtain materials they need – Moose and hare for food– Plants for light, CO2, minerals, water

Predation

• Animal (predator) hunts and kills another (prey) for food

Symbiotic relationship

When one organism lives on, near, or inside anotherCommensalism – only one member benefits, the

other is neither helped nor harmed• Sparrow builds nest under osprey nest. Sparrow gets protection, osprey gets nothing.

Commensalism• Starlings and other birds are often seen feeding on insects

amid cattle in the pasture. The feeding cattle stir up the insects and the birds catch them. This helps the birds and doesn't affect the cattle. This is not the same as birds that pick parasitic insects off the cattle, as that would be mutualism.

• The most common example is the clownfish and the sea anemone. The clownfish shelters among the tentacles of the sea anemone, and the sea anemone is not affected.

• Barnacles live on whales and get to be transported to different areas of the ocean to feed. The whales are not affected.

Symbiotic relationship

• Mutualism – when both organisms are helped• Snakes live at base of heron’s nest because heron drops

food. Snakes provide protection from raccoons and other animals

Mutualism

• The sea anemones and hermit crab The sea anemones give protection to the crab using its stinging cells as the crab remolds its shell to fit. The hermit crab allows the sea anemones to consume the remains of its food, thus it also provides the sea anemones with food supply

• The ant-plant association The plants provide the ants with nectar as a food supply whereas the ants helps the plants to keep away other insects from eating its leaves.

Mutualism• The nectar-producing plants and its pollinators

While the pollinators (such as bees, butterflies, etc) help to pollinate the plant for reproduction, the plants also provide its pollinators with nectar as food, thus both sides benefit.

• Lichen is an example of mutualism as well. Lichen is made up of algae and fungus; the algae, which is green and is able to photosynthesize, produces food for itself and the fungus, whereas the fungus takes in water for the algae, and together they form the lichen.

Symbiotic relationship

• Parasitism – one organism benefits (parasite), one organism is harmed (host)

• Lamprey will attach itself to another fish and suck its blood.

**a successful parasite will not actually kill its host