Ecology Facts Quiz

Ecology Test #2 Study Guide Name _____ANSWER KEY______

Directions: Using complete thoughts and sentences, answer the following questions on your own paper.

1. In the movie Finding Nemo, there were a total of 7 producers, 12 gallons of water, 2 filtration systems, 6 fish, 1 crustacean, and 1 echinoderm (starfish) in the dentist’s fish tank.

a. What is the population density of producers in the fish tank? Population density is the number of individuals in an area of a specific size. Producers are organisms that can make its own food. Plants are producers. So the answer is 7 producers.

b. What are two things that would be limiting factors for the six fish in the dentist’s fish tank? Limiting factors can be biotic (living) or abiotic (nonliving). Biotic factors could include things like food supply (prey), predators, competitors, etc. Abiotic factors could include things like temperature, oxygen availability, PH level, pollution, etc.

c. Take one of the limiting factors you listed and explain how it would be a limiting factor. Can take any biotic or abiotic factor listed above and explain how it limits a population such as if the fish were not fed their food supply (biotic) would drop and cause their population to decrease or a change in water temperature (abiotic) would cause the population to decrease, etc.

d. Explain what could occur to this ecosystem if the filtration system gets clogged (like the plan in the movie). An ecosystem is community of organisms that live in a particular area, along with their nonliving surroundings such as the fish tank and all of the organisms that live in it. So, if the filtration system were clogged the water would not get cleaned (polluted) and oxygen would not be added, both having negative impacts on the living organisms in that ecosystem (fish tank).

2. Describe an event where two organisms are competing. Be sure to include what they are competing for. Competition is the struggle between organisms to survive as they attempt to use the same limited resource. The four things that all living organisms need are food, water, shelter, and space so any two organisms could compete for these four things.

3. In 1976 Milliard and Linda Fuller began a non-profit organization called Habitat for Humanity, which builds homes for low income families. They’ve housed more than 3,000,000 people around the world and continue to be a source of assistance today. For example, in July there were three families who received houses in Tempe. Humanity means “people”. Explain why this organization is called Habitat for Humanity. Habitat is the specific environment that provides the things an organism needs to live, grow and reproduce or simply put a habit is a home. So, if humanity means people then Habitat for Humanity simply translates to ‘homes for people’ which is what they build and provide.

4. Using the picture below as a guide, write 2-3 sentences explaining why the introduction of invasive species is bad. You can write about the picture or about invasive species in general. Invasive species are species whose introduction does or is likely to cause economic or environmental harm or harm to human health. All invasive species are non-native species meaning species of organisms that is not native to an ecosystem or have moved into ecosystems because of human actions. So, invasive species can disrupt an ecosystem through predator-prey relationships, or as competitors, etc. 5. Explain three things that humans are doing that causes negative issues with the earth and the organisms on it. For each issue explain the impact on the organism, the food web, and the ecosystem. Humans impact the environment in MANY ways such as air pollution, water pollution, global warming, acid rain, deforestation, etc. Each of these things causes a negative impact to organisms and their ecosystem such as water pollution can possibly kill off producers or plankton which are the basis of an aquatic food web and then the rest of the food web is affected. 6. Many fish seek out rocky areas in fast-flowing currents to deposit their eggs during spawning season. Unfortunately, many of the reefs and rocky areas have been destroyed. Similar spawning (reproduction of fish) areas in certain rivers were not able to be reached anymore because of dam construction. Despite population declines, the rivers connecting Lakes Huron and Erie continue to support the largest remaining population of lake sturgeon (a type of fish) in the Great Lakes. What can you do as an ecologist to help restore the sturgeon’s habitat? Develop and explain three ideas. Habitat restoration is the process of taking action to bring a damaged habitat back to a healthy condition. So, in this scenario you would want to address the destruction of the reefs and rocky areas as well as the dams that are stopping the fish from reaching other similar habitats. 7. “When we tug at a single thing in nature, we find it attached to the rest of the world.” John Muir Explain what the quote means and then give a specific example of how things are connected in nature. John Muir was a naturalist that started the movement in the 1800’s for wilderness areas to be preserved. Ecology is the study of how organisms interact with their environment and the idea that basically everything is connected in one way or another via food webs and food chains or limiting factors (biotic and abiotic). So, if we as humans for example overfish a fish population it can change that food chain and web and even ultimately the ecosystem.

8. Although no one is quite sure when exactly the Tiger mosquito arrived in the United States, most people are sure that it was accidentally transferred to this country in shipping of used tires in the 1980’s. The Tiger mosquito feeds throughout the day unlike other mosquito species. Tiger mosquitos are also larger than other mosquitos and are also able to better compete for breeding space and territory. In 2-3 sentences explain why the Tiger mosquito is an invasive species. Invasive species are species whose introduction does or is likely to cause economic or environmental harm or harm to human health. All invasive species are non-native species meaning species of organisms that is not native to an ecosystem or have moved into ecosystems because of human actions. So, invasive species can disrupt an ecosystem through predator-prey relationships, or as competitors, etc. In this case they outcompete the other mosquitos.

9. During the monsoon thunderstorms of this year, many of the local areas around Phoenix became flooded or even washed away. In some of the most extreme places the trees, cactus, and most other producers are now gone. This resulted in a loss of habitat for man desert dwelling creatures. Create a habitat restoration project for the area. There is no right or wrong answer as long as you can justify why you are doing it. Or, you can explain to me why we should not interfere and restore the habitat (if that is what you think). Habitat restoration is the process of taking action to bring a damaged habitat back to a healthy condition. So, in this case you would want to address the initial issue mentioned which was the destruction of producers by replanting and replacing them since they are the basis or bottom to any food chain and web. If you were taking the side of NOT restoring the habitat then you are saying that you are letting nature run its course and that new producer species may thrive and a whole new ecosystem COULD develop if man does not interfere.

10. In many places forests are clear cut much like the pictures we saw during our Amazon Rainforest presentation. In 2-3 sentences explain what will eventually occur if humans continue to clear cut forests. Also explain what we can do instead to help ensure a healthy ecosystem. Clear cutting is when you come in and cut EVERYTHING down whether you need it or not and then just pick up and take the trees that you want leaving the others laying there. Selective cutting is the process of cutting down only some trees in an area so you mark and then cut ONLY what you want and need and leave the others standing. If we continue to clear cut and destroy the forests (deforestation) then we are eliminating a valued resource and habitat. Trees absorb carbon dioxide and put off oxygen as well as provide habitat for many organisms. Deforestation decreases biodiversity. Selective cutting is clearly better and healthier for the ecosystem as you are not destroying the entire forest.