Bio 1.4 - Review

The image provided shows a partial East Texas food web.

How could the removal of the milk snakes affect the ecosystem interactions?

• The white-tailed deer population would decrease.

• The white-tailed deer population would increase.

• There would be greater energy available to be transferred to the great-horned owls.

• There would be a decrease in energy available to be transferred to the ants. 

Local environmentalists have noticed that a bird population has decreased in a local forest. They think that pollution from the nearby chemical plant is to blame. After pressure from the community the factories put filters over their smokestacks to trap pollution before it is released into the air. Why would city officials need to monitor the bird population after the factories solved the issue?

• To ensure that the filters stop harming the bird population. 

  
  

• To ensure the public stays interested in the bird population.

  
  

• To make sure that all pollutants were removed from the environment.

• To make sure the bird population does not pass on a mutation to a different species.

The local town relies on this river ecosystem to sustain their population both economically and as a source of food. Using the food web provided, which statement provides the best reasoning for regulating the amount of fish removed from the river by humans? 

• 1. Regulation will increase the amount of energy transferred from the catfish to the eagle.

• Regulation will allow contaminated sediments to decrease in the river due the removal of the contamination source.

• Regulation will ensure that carp will not overpopulate the ecosystem and begin to consume larger organisms like the salmon.

• Regulation will help the ecosystem to remain balanced and contribute to the stabilization of other populations of river organisms.

Which activity would you predict is most likely to have the smallest impact on environmental systems?

• using land to create a national park
• building a dam for energy production
• building new housing in an area far from a city
• using more land to grow corn that is used to produce fuel

Legislation was introduced in 1987 to ban the use of compounds that were depleting the ozone layer. The graph below shows the levels of halogens in the atmosphere for several years after the legislation was passed.What conclusion can you draw from this graph?

• The size of the ozone layer decreased during this time period.
• The concentration of ozone in the upper atmosphere increased during this time period.
• The concentration of halogens in the atmosphere decreased during this time period.
• The size of Antarctica below the ozone layer decreased during this time period.

DDT is a chemical that was banned from use 50 years ago, but is found in glacier runoff today. Glacier runoff occurs in the summer when precipitation falls on glaciers. Which of the following best explains why is it important that officials continue to monitor environmental parameters affect by DDT?

• to ensure that DDT is not in use
• to determine long lasting effect of DDT on biodiversity
• to determine the impact of DDT on the health of individuals
• to evaluate how long it takes for DDT to breakdown in an ecosystem

A local company has requested a permit to dredge a passage in the local waterway. The county commissioners are looking over the permit and request environmental monitoring to take place. Why is it important to monitor the waterway before, during, and after the dredging has occurred?

• To assess fines on the company if the environment is damaged.
• To determine how local fish populations are affected by the dredging
• To find other possible locations for the company to dredge in the future.
• To allow city officials to protect human health from the change in the waterway.

Genetic engineering is being used to genetically modify crops to be resistant to pests allowing farmers to use less chemicals. If farmers plant more genetically modified crops, what would be an environmental impact of this biotechnology?

• A decrease in crop productivity
• An increase in the use of pesticides
• A decrease in the genetic diversity of the crops
• An increase in the contamination of the water supply

Scientists have inserted a gene into a population of grasshoppers. This gene gives the grasshoppers immunity to a common pesticide. The gene was initially found in some pesticide-resistant cockroaches and was then inserted into the grasshopper population. Which of the statements below best explains the impact of inserting the gene for pesticide immunity into the grasshopper population?

• The grasshopper population will be more likely to survive a drought.
• The grasshoppers will learn to feed in areas where no pesticides are being used.
• The population of grasshoppers will be able to be sprayed with the pesticide and remain unaffected.
• The grasshoppers will use more energy to resist the pesticide which will cause a decline in their population.

Critics of deep sea mining say it is important to have protected areas. Many scientists suggest measuring the number of species before sea mining begins and monthly after sea mining begins. Why is this an important parameter?

• To ensure biodiversity decreases

• To ensure biodiversity does not decrease

• To determine the best area to set up sea mining.

• To determine the number of minerals in an area.