Thanksgiving Break FRQs

Explain what is meant by a metapopulation and how it relates to the desert bighorn sheep.

"Metapopulation" refers to a group of separate populations in which individuals move between the habitat islands. This helps to recolonize islands where populations may go extinct. Metapopulation relates to the desert bighorn sheet because they are a metapopulation that travels extensively through habitat corridors and allow for genetic variation.

Based on the information above, is the western lowland gorilla an r-selected or a k-selected species? Provide evidence to support your answer.

A k-selected species is most notably identifies by producing few offspring over a longer period of time. The western lowland gorilla is a k-selected species because they produce on offspring every four years and take a long time to mature: 15 years for males and 8 years for females.

Propose a realistic solution to prevent eutrophication of waterways near CAFOs

A possible solution to prevent eutrophication near CAFOs is to decrease the use of fertilizers. Residual nutrients from high fertilizer use can run off into waterways. Decreasing fertilizer use would mean less nutrient residue that can contribute to eutrophication.

Identify a toxic metal other than mercury that has a negative impact on human health and describe how it is introduced into the environment. Describe an acute sublethal effect on humans that results from exposure to this metal.

Another toxic metal that can cause negative impacts on human health is lead. This toxin is introduced into the environment through cigarette smoke. An acute sublethal effect on humans that can result from exposure to lead is menstrual problems or strokes.

Explain why there are greater health risks associated with eating large predatory fish, such as tuna and sea bass, than from eating small nonpredatory fish.

Consuming large predatory fish leads to greater health risks as predatory fish often contain higher mercury concentrations than nonpredatory fish because mercury concentrations increase in higher trophic levels. This occurs due to bioaccumulation and biomagnification. Bioaccumulation describes the process by which a toxin builds up in the tissue of an animal. Biomagnification describes the concept that the higher an animal is in a food chain, the greater the concentration of the substance is in their body. Over their lifespan, older predatory fish have more time to eat smaller nonpredatory fish that cause mercury to bioaccumulate and increase their toxicity.

Describe how eutrophication negatively affects waterways

Eutrophication describes the process when a body of water becomes overtaken by an excess of nutrients. During eutrophication, plant life density increases and animal life decreases due to a lack of oxygen. This lack of oxygen is largely caused by algal blooms during which bacteria use oxygen to break down dead organism and output carbon dioxide. This process leads to dead zones in which the pH decreases and carbon dioxide production is increased.

Explain the consequences to the desert bighorn sheep population if the plan to connect the mountain habitat islands is not implemented

If the plan is not implemented, genetic variation would be stunted and sheep populations would be isolated to their habitat islands. This could potentially lead to inbreeding which would serve as a direct detriment to the survival of the population. Smaller populations are at a higher risk for extinction which would make it more difficult to recolonize. The plan to connect the habitat islands would promote genetic diversity thus helping to support an island population.

Identify and explain four community interactions that involve the western lowland gorilla.

One community interaction is the competition between humans and gorillas. Humans and gorillas compete for resources. Humans use trees for industry use like lumber while gorillas rely on trees for their habitat. Both humans and gorillas eat fruits. Another interaction is the parasitic relationship between gorillas and viruses like Ebola which live inside of the gorillas. Additionally, gorillas have a predatory relationship to ants and termites because they eat them. They assume a consumer/predatorial role in their ecosystems. Finally, gorillas interact with leopards. In this relationship, gorillas are prey for leopards who hunt them.

Identify two density-dependent factors and one density-independent factor that could affect the populations of desert bighorn sheep.

One density-dependent factor that could affect the sheep is high competition, or a lack of food or resources for survival. A second density-dependent factor is disease which could sweet the population. One density-independent factor is droughts which can impact their access to life-supporting resources.

On the basis of the article above, indicate one human activity that releases mercury into the environment. Describe how mercury is transported from that source and enters aquatic systems, often hundreds of miles away

One human activity that releases mercury into the environment is the burning of fossil fuels like coal. Mercury is transported through air currents and enter aquatic systems as dry particles that fall into soil or water. Once the particles have reached the water, they may be transported with evaporation into the atmosphere where they can be further transported hundreds of miles away from their original source.

Justify the solution you just described with an additional environmental benefit

Reduced use of fertilizers can decrease the severity of eutrophication which reveals another environmental benefit. Since a major side-affect of eutrophication is increased CO2 production, reduced fertilizer use would cut down on CO2 production which contributes to global warming. Additionally, less nitrous oxides would enter the atmosphere to contribute to the creation of tropospheric ozone: a harmful greenhouse gas.

Explain what is meant by secondary succession and describe how it may be initiated in a tropical forest.

Secondary succession often occurs after a disturbance such as a wildfire. It happens in an area that lacks vegetation but the soil is still intact. In a tropical forest, secondary succession may be initiated by events like forest fires or storms.

Describe TWO ways that the amount of mercury released into the environment from the source in part (a) could be reduced.

The first way that mercury output can be reduced is by using sorbents such as activated carbon to convert gaseous mercury into an insoluble, thermally stable compound that can be removed by wet scrubbers. This removal decreases the amount of mercury byproduct that can enter the environment. A second way to decrease mercury input is to use an alternate energy source like natural gas or solar power. These energy sources have a far lower or nonexistent mercury contamination component.

Explain how the theory of island biogeography applies to the mountainous areas of Southeastern California.

The theory of biogeography says that larger habitat islands will have a greater biodiversity than a smaller habitat island. In the mountainous areas of Southern California, larger habitat areas will contain a greater number of species which will mean less extinction. In the example plan to connect habitat islands, this would allow for habitats to merge and introduce new populations that would further increase biodiversity and promote success within an ecosystem.