Rank the oxygen level in each stage from highest to lowest.

1. the availability of food, water, shelter and space.

2. Common limiting factor resources are environmental conditions that limit the growth, abundance, or distribution of an organism or a population of organisms in an ecosystem. The limiting factor also causes competition between individuals of a species population.

Example: Space, food, or water.

3. Limiting factors, such as food, would sometimes cause one organism to kill another to survive or fight over that factor. But with space, it would get crowded probably.

4. ( i couldn't find anything about South America Ecosystems Interactive... sorry )

5. "Native people" are ethnic groups who are the original inhabitants or descendants of the original people.

Example: the Yanomami and the Tupi People of the Amazon.

6. I would say do an experiment or something???

7. A variable is any factor, trait, or condition that can exist in differing amounts or types.

8. The dependent variable is what is being measured in an experiment or evaluated in a mathematical equation. The dependent variable is also called the outcome variable.

9. A typical use of a control group is in an experiment in which the effect of a treatment is unknown and comparisons between the control group and the experimental group are used to measure the effect of the treatment.

Example: when testing for a new pill, one group is given the pill to see affects, one group (the control group) is given a placebo and is used to see what happens when given a placebo.

10. Changes in limiting factors will cause a population to decrease.

11. They are transmitted from indirect contact usually.

12. An animal or plant on or in which a parasite or commensal organism lives.

Example: When a human doesn't wash his/her hands and that makes someone else sick. Another one is since humans naturally have bacteria, some are bad and can cause a virus.

13. An infectious agent is something that infiltrates another living thing.

14. Lack of membrane-bound organelles, unicellular, and small.

15. cocci, bacilli, and spirilla.

16. Viruses can replicate only by infecting a host cell and they cannot reproduce on their own.

17. Influenza, HPV, and rabies.

18. Any of a group of unicellular, multicellular, or syncytial spore-producing organisms feeding on organic matter.

Example: Pink waxcap, coral tooth, and pig's ear. (this is not their scientific name haha)

I hope this helps :D