1. Science 7 - Unit A: Interactions and Ecosystems Topic 1: Interactions Within an Ecosystem

2. Unit A: Interactions and Ecosystems Focus Questions: Focus Questions: How do human activities affect ecosystems around us? How do human activities affect ecosystems around us? What methods can we use to study the changes in ecosystems? What methods can we use to study the changes in ecosystems? How can we measure the effect we are having on ecosystems? How can we measure the effect we are having on ecosystems?

3. Ecology Is the study of the relationship between living things and their non-living environments. Is the study of the relationship between living things and their non-living environments. Someone who studies these relationships is an ecologist. Someone who studies these relationships is an ecologist.

4. Ecosystems Ecosystem = an area where living (biotic) and non-living (abiotic) things interact with each other. Examples of biotic factors include insects, grass, flowers, and humans. Examples of biotic factors include insects, grass, flowers, and humans. Examples of abiotic factors include air, water, soil, and buildings. Examples of abiotic factors include air, water, soil, and buildings. Animals and plants of an ecosystem are split up into species. A species is any kind of organism. If two animals are able to reproduce with each other they are part of the same species, if not they are two different species. Animals and plants of an ecosystem are split up into species. A species is any kind of organism. If two animals are able to reproduce with each other they are part of the same species, if not they are two different species.

5. Populations and Communities A population is a group of the same species living together in an ecosystem. Examples include an ant colony, a bee hive, and a pack of wolves. A population is a group of the same species living together in an ecosystem. Examples include an ant colony, a bee hive, and a pack of wolves. A community is all the populations of living things of an ecosystem. A community is all the populations of living things of an ecosystem.

6. Basic Needs of Living Things Water Water Food and nutrients Food and nutrients Energy Energy Oxygen Oxygen Suitable living conditions - Habitat Suitable living conditions - Habitat (usually provided by shelter) An ecosystem must provide the basic needs of a population or the population will leave the ecosystem, or die. An ecosystem must provide the basic needs of a population or the population will leave the ecosystem, or die.

7. Adaptations There are two general goals in life for living things: 1. Survive and 2. Reproduce. There are two general goals in life for living things: 1. Survive and 2. Reproduce. Adaptations are any INHERITED characteristic that improves an organism/species ’ s chances at survival and reproduction. Adaptations are any INHERITED characteristic that improves an organism/species ’ s chances at survival and reproduction. Eg. A lion ’ s mane helps attract mates, and its yellow fur helps provide camouflage when hunting. Eg. A lion ’ s mane helps attract mates, and its yellow fur helps provide camouflage when hunting.

8. Symbiosis Symbiosis – a relationship between two organisms where at least one of them benefits. There are three kinds of symbiotic relationships. Symbiosis – a relationship between two organisms where at least one of them benefits. There are three kinds of symbiotic relationships. Parasite – is the organism which attaches onto the larger host and lives off them in some way. They are usually smaller than the host. Parasite – is the organism which attaches onto the larger host and lives off them in some way. They are usually smaller than the host. Host – is the organism which can exist without the other. The parasite needs the host more than the host needs the parasite. They’re also usually bigger than the parasite. Host – is the organism which can exist without the other. The parasite needs the host more than the host needs the parasite. They’re also usually bigger than the parasite.

9. I. Commensalism A symbiotic relationship where the parasite benefits, and the host organism is not affected either way (neutral). A symbiotic relationship where the parasite benefits, and the host organism is not affected either way (neutral). The Remora fish benefits from hanging around sharks, eating its scraps, while the shark is not affected. The Remora fish benefits from hanging around sharks, eating its scraps, while the shark is not affected.

10. II. Mutualism A symbiotic relationship where both the parasite and host benefit. A symbiotic relationship where both the parasite and host benefit. Certain species of birds live on the back of large mammals such as hippopotamuses and eat the insects and pests which bite and irritate the hippo, therefore both benefit. Certain species of birds live on the back of large mammals such as hippopotamuses and eat the insects and pests which bite and irritate the hippo, therefore both benefit.

11. III. Parasitism This is a symbiotic relationship where the parasite benefits, but the host suffers. This is a symbiotic relationship where the parasite benefits, but the host suffers. An example of a parasitic relationship would be lice and humans, or bedbugs and humans, or fleas on dogs. An example of a parasitic relationship would be lice and humans, or bedbugs and humans, or fleas on dogs.

12. Impacts on Ecosystems  Humans, plants and animals can drastically change, create, and destroy ecosystems. A beaver dam or a highway can change an ecosystem. Abiotic factors can also change an ecosystem. A forest fire, flood, ice age all can have a huge impact on ecosystems. Abiotic factors can also change an ecosystem. A forest fire, flood, ice age all can have a huge impact on ecosystems.