Please answer the following questions in a 200-word response minimum. Try your best to reference the text I will message you privately for how to access the text book. Or you can access it at this link (it may take some time to load):

https://vk.com/doc257194956_437096191?hash=744dc3a08c6c00873f&dl=fdb9fff13f8ef8f1b1

1. Explain the exponential model of population growth. Explain the logistic model of population growth. Which model is more realistic to what happens in nature? Which model does the human population most closely resemble? Explain your answers.

2. How does your textbook define ecosystems? How do they work? Describe some human activities that affect ecosystems (good or bad).

3. Please use the link below to answer the following question;How do biotic and abiotic environmental components interact, and how does this affect population growth and regulation?

Link: https://www.khanacademy.org/science/biology/crash-course-bio-ecology

4. Please use the link below to answer the following question;How have human activities affected ecosystems and the biosphere?

Link:https://www.khanacademy.org/science/biology/crash-course-bio-ecology

5. Please use the link below to answer the following question;How do energy and materials flow in an ecosystem?

Link:https://www.khanacademy.org/science/biology/crash-course-bio-ecology

Please participate (respond) to the classmates answers with POSITIVE notable and educational input. (200 word minimum Reponses)

1. Katherine: This is an interesting piece from The Oregon State University regarding how human caused pollution has affected the fish in our waterways. The reason why I say this there recently was an article in the local newspaper here about the same thing. For some reason the scientists state it may be causing the brown tide found on the south shore. The nitrogen levels have become much higher than a few years ago. Also the further out on the ocean it has been stated that the deep water marine fish have liver pathologies, tumors and other issues because of the human pollution. It has actually caused mutation of the male fish whereas they are capable of laying eggs like a female. What is also being said is that there are many contaminants like mercury, cadmium and lead and the organic contaminants like PCBs and pesticides that has been found in the waters and ground surfaces around the waterways. All of these contaminants are because we do not watch what we throw in our trash cans on a daily basis without thinking what harm it does to the environment.

http://longisland.news12.com/news/scientists-brown-tide-threatening-li-marine-life-1.11973045

Oregon state university; A mile deep, ocean fish facing health impacts from human pollution. (2015). NewsRx Health, , 13. Retrieved from http://search.proquest.com/docview/1668300941?accountid=458

2. Brooke: The difference in exponential growth and logistic growth models can be explained pretty simply. Exponential growth on a graph is a J shape, so it can be referred to as the J curve. It measures the growth of a population with our any limiting resources. The graph curve illustrating logistic growth is S shaped, so it is referred to as the S curve. Logistic growth measures the intrinsic growth rate of a population with density dependent and independent factors, and unlike exponential growth, has a leveling off point, or carrying capacity that is determined by said factors. Since the logistic growth rate includes factors such as water and food resources, it is a more realistic model of what happens in nature. Realistically the human population growth rate would be illustrated best in a logistic growth rate model because with the increase population comes strain on our resources. The growth rate our professor provided of the human population looks more like an exponential growth rate model (J shaped) probably due to the industrialization of most nations and the accessibility to food, medicine, and clean water, people tend to live longer and have more healthy children, but should still have a leveling off point.

3. Jason: The definition for ecosystem is a biological community of interacting organisms and their habitat. Soil is one part of the ecosystem, the soil provides nutrients and helps anchor plants to hold them in place. Also the soil absorbs water for other animals and plants to drink as well as a home for some animals. The sun is another major part of an ecosystem, it provides heat for plants and animals to stay warm. The suns light is the main part of photosynthesis, so plants can produce food. Water is probably the most important part of the ecosystem, many of the cells of an organism are made up of water, also is used by plants, animals, and humans as well.

There are 3 main categories, producers, consumers, and decomposer's. Producers would be the plant life, Consumers would be the herbivores, omnivores, and carnivores, while the decomposer's are the organisms that turn dad plants and animals back into organic material. The broken down materials then return to soil and the cycle starts over again.

Pollution would be the biggest threat us humans appose onto an ecosystem. Cars, trucks, trains, and ships all produce numerous harmful pollutants through the exhaust and as those gases get into the atmosphere they pose some serious threats to the well being of an ecosystem. Another threat is land conversion, the building of roads, shopping centers, and even home developments, severely change he land and can wipe out some organisms completely.