SPEAR: EOC Practice

A research group has discovered that damselflies, a type of dragonfly, are being infected by a particular type of aquatic protozoan. Both young and adult damselflies are not directly infected by the protozoan but contract the infection from the prey they eat. The graph above shows the percentage of adult damselflies infected by protozoans during the summer and early fall. Which of the following conclusions is supported by the graph?

The common brushtail possum is a marsupial native to Australia. This possum was later introduced to New Zealand where it had no natural predators and had an abundant food supply. Which of these likely occurred in New Zealand a few years after the introduction of this possum?

Mullet are local estuarine fish that move in schools and feed on plankton and plant matter. Natural predators of the mullet include spotted sea trout, sharks, pelicans and dolphins. The graph above shows how the number of mullet in an area has changed over time.

Based on the data, one student concludes that a new predator was introduced into the area during this time period, but the teacher asked her to consider an alternative explanation. Which of the following is a likely alternative explanation for the change in the mullet population?

The pea weevil is a type of insect. The data table above shows the average time it takes for pea weevil eggs to hatch at different temperatures. Based on the data, which of the following conditions would promote the highest population growth rate in pea weevils?

Changes in an ecosystem over a long period of time are shown in the diagram above. These changes most likely will lead to which of the following situations?

A biologist compares how different ecosystems undergo succession. She divides the series of events that happen during primary and secondary succession into three different stages. Which feature might be used to distinguish secondary succession from primary succession?

After the Aswan High Dam was built on the Nile River, the rate of parasitic blood-fluke infection doubled in the human population near the dam. As a result of building the dam, the flow of the Nile changed. This changed the habitat, which resulted in an increase in its population of a certain aquatic snail. The snails, which were infected, released larvae of the fluke. These larvae then infected humans. Which of the following statements is best illustrated by this situation?

A builder is proposing a new housing development in an area of western Massachusetts. Construction of the housing development will destroy the wetland habitat in the area. Which of the following would be the most likely consequence of the wetland’s destruction?

DDT and other pesticides used over 50 years ago are still affecting the environment today. Scientists have found these substances in recent glacier runoff. Glacier runoff occurs during the summer, when precipitation that has fallen on glaciers during the winter is released. Ice layers from existing glaciers have been analyzed. The results of this analysis show that the concentrations of DDT and other pesticides were highest about 10 years after the use of these substances was banned.

What is the best observation that can be made from the DDT?

The diagram above shows part of the carbon cycle. If many trees are removed from a forest by logging, what is the most immediate effect on the carbon cycle in that forest?

Acid rains form when air pollution combines with moisture in the atmosphere and falls to Earth as precipitation that has a low pH. Which of the following effects cannot be attributed to acid rain?

Constance made the table above during a field investigation on ocean life. Based on Constance’s table, which of the following is a valid conclusion?

The tropical rain forests have been called the lungs of the planet. They take huge quantities of carbon dioxide from the atmosphere during photosynthesis and give off large quantities of oxygen. Vast tracts of tropical rain forests are being cleared for farms by people cutting down and burning the trees. Which of the following is the best hypothesis about the effect that rain forest destruction may have on atmospheric carbon dioxide levels?

Your class has been observing the population growth of a species of Paramecium, a single-celled organism, for 18 days. Your data are shown in the graph above. Food was occasionally added to the test tube in which the paramecia were grown.

Look at the graph above. What is the carrying capacity of the test-tube environment as long as food is added?

Examine the table above. Which of the following graphs most closely represents human population growth based on the data provided above?

As an increasing amount of carbon dioxide is sent into the atmosphere by burning fossil fuels, the oceans absorb more and more of the excess carbon. Some of the carbon reacts chemically in seawater to form an acid. The more carbon the ocean takes in, the more acidic the water becomes. If the water becomes too acidic, tiny organisms that make up plankton may not be able to make protective shells. One of the areas that would be greatly affected is the Antarctic. What effect, if any, might this harm to plankton have on an Antarctic marine food web?