BM2 Week 4 Review Flashcards
Worldwide, how are nearly three-fourths of infectious diseases transmitted?
Water
What kind of pollutant is found in vehicle exhaust, burning waste, fires, and tobacco smoke?
Particulate Matter
People’s actions cause some disease-causing bacteria to become resistant to what?
Antibiotics
Why do people lobby?
To influence governmental policies
Which term describes the condition in which humans can survive indefinitely as their needs are being met?
Sustainability
How are tropical rainforests and grasslands threatened by human activities? Give one example for each biome.
tropical rain forests: habitat destruction due to activities such as logging, agriculture, or trading of exotic plants and animals; grasslands: farming and overgrazing that lead to erosion
Explain how climate determines the distinguishing characteristics of different biomes.
Climate is the weather conditions that exist in an area over a long period of time. These conditions, which include temperature and precipitation, determine the type of plants and animals that can survive in a biome. The biome is thus characterized by the dominant plant and animal species.
Imagine that one species no longer exists, or becomes extinct, immediately after the extinction of another species. Which relationship did the two species more likely have, competition or commensalism? Explain your reasoning.
Commensalism; if the organisms were competing for resources, then the extinction of one would make more resources available for the other; thus, the other should thrive. If species A derives benefit from species B and species B becomes extinct, then species A might also become extinct.
Explain whether or not people should be concerned about the loss of biodiversity. Give examples of how biodiversity benefits both humans and the biosphere.
The interdependence of the wide variety of life forms on Earth is critical to ensuring that the various nutrient and energy cycles of Earth remains in balance. This balance is responsible for the quality of our air, water, and soil. Microorganisms such as the bacteria that live on the roots of some plants, for example, are an integral part of the nitrogen cycle. The effect of removing keystone species such as the Pacific sea otter demonstrates the role of individual organisms in maintaining the stability of ecosystems. Moreover, undiscovered or poorly studied species are a potential source of new chemicals, industrial materials, medicines, and new genes for crop breeding or genetic engineering. The extinction of such species could thus result in the loss of useful products.
Describe the role of water as a factor in the spread of cholera and malaria.
Cholera pathogens are introduced into water by human feces. The pathogens breed in the polluted water and infect humans when they drink the water. Malaria is caused by a parasitic protist that lives in mosquitoes. Humans get malaria when they are bitten by an infected mosquito. The mosquito vector lays her eggs in stagnant water. The more stagnant water that is available, the larger the population of mosquitoes can become and the greater the chance of a human being bitten.
