Question

1. 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?

a. the size of the ozone layer decreased during this time period.
b. the concentration of ozone in the upper atmosphere increased during this time period.
c. the concentration of halogens in the atmosphere decreased during this time period.
d. the size of antarctica below the ozone layer decreased during this time period.

1. 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 affected by ddt?

a. to ensure that ddt is not in use
b. to determine long - lasting effect of ddt on biodiversity
c. to determine the impact of ddt on the health of individuals
d. to evaluate how long it takes for ddt to breakdown in an ecosystem

1. 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?

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

1. 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. a decrease in crop productivity
b. an increase in the use of pesticides
c. a decrease in the genetic diversity of the crops
d. an increase in the contamination of the water supply

Explanation:

1. The graph shows the levels of ozone - destroying halogens decreasing over time after the 1987 legislation. So, the concentration of halogens in the atmosphere decreased during this time period.
2. DDT was banned long ago but is still found in glacier runoff. Monitoring environmental parameters helps determine its long - lasting effects on biodiversity as it can accumulate in the food chain and affect various species.
3. Dredging can have a significant impact on aquatic life, especially fish populations. Monitoring before, during, and after can help understand how local fish populations are affected.
4. Planting more genetically modified crops can lead to a decrease in the genetic diversity of crops as fewer natural varieties are planted.

Answer:

1. c. The concentration of halogens in the atmosphere decreased during this time period.
2. b. to determine long lasting effect of DDT on biodiversity
3. b. To determine how local fish populations are affected by the dredging
4. c. A decrease in the genetic diversity of the crops