Student ID #22042666
Exam # 25085500
1. Explain how human activities can cause an imbalance in biogeochemical cycling and lead to problems such as cultural eutrophication and fish kills.
Eutrophication is a naturally occurring, slow, and inevitable process. However, when it is accelerated by human activity and water pollution called cultural eutrophication, it can lead to the premature aging and death of a body of water. Cultural eutrophication occurs when humans speed up the aging process by allowing excessive amounts of nutrients in such forms as sewage, detergents, and fertilizers to enter the ecosystem.
2. Compare and contrast the traits and growth patterns of opportunistic versus equilibrium populations.
Opportunistic species use the r-strategy. They produce millions of eggs and sperm since only a small percent will actually meet, join, and become offspring. Opportunistic species are often the first to colonize a new environment with a “boom and burst” growth pattern, with a short life cycle. They tend to "crash" when they run out of food, space, oxygen, sunlight, or whatever the limiting factor is in that environment.
Examples are most insects, and corals, barnacles, clams, scallops and oysters, who spawn and fertilize their eggs in the water.
Equilibrium species use the K-strategy. The carrying capacity of the environment. These species produce much fewer offspring and usually brood them and/or take care of them in other ways. The populations of these species may first grow exponentially, but the growth levels off when they reach the carrying capacity of the environment. They prefer a stable predictable environment and have a long life cycle. Most birds and mammals use this strategy, as well as some live-bearing fish like dogfish sharks.
3. Compare and contrast indirect versus direct values of biodiversity, and provide examples.
Biodiversity is the degree of variation of life. This can refer to genetic variation,