GED Scientific Study pt1

In the 21st century, worker bees in bee colonies have been abandoning their queens and are deserting their hives in record numbers. Known as Colony Collapse Disorder, honeybees have been mysteriously disappearing across the planet—and one area that has been seriously affected is California’s Napa Valley. This issue became more commonly known when The National Agriculture Statistics Service reported in 2008 that only 2.44 million honey-producing hives were in the United States, down from 4.5 million in 1980.

There is no consensus among scientists as to what is causing Colony Collapse Disorder, though the USDA has undertaken a plan of action to stem the collapsing colonies involving several steps: survey and data collection; analysis of samples; hypothesis-driven research; mitigation and preventive action. The first findings from the USDA were published in 2009, and suggested factors such as pesticides, parasites, and pathogens may be possible causes, all of which have affected hives in Northern California.

One researcher has hypothesized that chemical pesticides are solely responsible for colony collapse disorder in Napa Valley. To test her hypothesis she is planning to run an experiment. She has obtained several healthy bee colonies and plans to expose them to pesticides while measuring the health of the colonies.

Which additional information would be the most useful in helping her design this experiment?

• The types of pesticides that are used in Napa Valley

• The types of parasites that are present in Napa Valley.

• The types of pathogens that are present in Napa Valley.

• All of the above.

A study was done to measure the effectiveness of an antibiotic on different bacteria. The antibiotic Vancomycin was tested on 3 types of bacteria: Enterococcus, Staphylococcus, and Streptococcus. Bacterial growth was measured at 3 different durations of time exposure to the antibiotic: 1 hour, 24 hours, and 7 days. The rate of bacterial growth was measured by bacterial colony size at each time interval. The data for each duration was calculated and compiled into the graph shown below. As a control, each bacteria species was also grown with no exposure to the antibiotic. This control culture was measured after 7 days.

What are the independent and dependent variables in this experiment?

• The independent variable is the bacterial colony size; the dependent variable is the type of bacteria.

• The independent variable is the duration of exposure to Vancomycin; the dependent variable is bacterial colony size.

• The independent variable is the bacterial colony size; the dependent variable is the duration of exposure to Vancomycin.

• The independent variable is the duration of exposure to Vancomycin; the dependent variable is the type of bacteria.

A laboratory produces and tests a new flu vaccine designed to prevent the influenza virus. The lab tests four dosages of the vaccine on 400 individuals, male and female, between the ages of 18 and 65 over a 3-month trial during flu season. Each group has 100 randomly assigned participants. The table shows the dosages of the flu vaccine given to each individual in the group, as well as the number of individuals that reported having influenza during the 3-month trial.

The laboratory has published findings in which they claim that the new flu vaccine can prevent the influenza virus. However, a competing lab has criticized the findings, claiming that there is an error in the way the groups were setup.

What changes to the test setup would eliminate the source of the error?

• Test a fifth group at a higher dosage than 200 mg.

• Only use two groups instead of four groups so the data is easier to compare.

• Make the difference in the dosage amount between the groups much larger.

• Add a fifth group to the study and set the dosage to 0 mg/day.

Many individuals concerned with their carbon footprint are excited about the availability of hybrid electric vehicles. These cars are much more efficient in their use of fossil fuels than similarly sized internal combustion automobiles. However, hybrid electric vehicles do come with an environmental price tag. Their construction uses scarce metals, such as neodymium, lithium and lanthanum. Additionally, mining these elements involves pumping acids into deep boreholes to dissolve the surrounding rock and then removing the acid and mineral slurry. Such extraction processes are a type of surface mining, which have severe environmental impacts such as erosion, acid mine drainage, water pollution, and disruption of habitat.

Based on the passage above, what are the environmental trade-offs of hybrid electric vehicles?

• There is only enough lanthanum available in the world to meet the demand of the Toyota Prius.

• While hybrid cars may reduce our dependence on fossil fuels, they may also increase our dependence on metals that are extracted from the ground in a destructive manner.

• Water near surface mining operations is highly acidic, sometimes with a pH of 2.5 or lower.

• Toyota obtains its lanthanum from China.

Battery companies make impressive claims about how long their batteries will last. A student decided to test the running time of different batteries to determine which battery lasts the longest. The student tested 6 different batteries, 4 brand name and 2 generic, using flashlights. The results show that the battery referred to as Name Brand A lasted the longest, with 101 hours of runtime as shown in the diagram.

It could be argued that this experiment was not set up using proper experimental protocol. What would need to change in the experiment for the results to be valid?

• The batteries should have all been either name brand or generic

• Only two groups should have been tested at a time

• The same battery should have been used in each flashlight

• The same flashlight should have been used to test each battery