STAAR Master II

A troglobite is any animal that lives in dark caves. These animals have special features that help them live in cool, dark places, like the caves in western Maryland. Many cave millipedes, a type of troglobite, have long antennae that feel vibrations. Northern cave fish, another troglobite, have very little skin coloring and cannot see. Animals in caves eat bat waste, material from dead plants, and animals that wash into the cave.

A population of troglobite cave fish is moved from a cave habitat to an open-air pond.

The cave-fish population in the open-air pond will most likely--

• increase because their food supply increased

• decrease because they are too large to live in a pond

• increase because their reproduction rate will increase

• decrease because they do not have features needed to survive in sunlight

The pea weevil is a type of insect. The table 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?

• cold springs with temperatures from 11 C to 16 C

• moderate summers with temperatures from 25 C to 27 C

• heat waves in which the temperature is sustained well above 28 C

• overnight frosts after which the temperature warms from 0 C to 11 C

The number of organisms an environment can support depends on the availability of environmental resources. Changes in the mule deer population in Nevada from 1900-2000 are shown in the graph.

During which years did the mule deer population most likely experience the greatest decrease of environmental resources?

• 1930-1950

• 1956-1960

• 1960-1970

• 1976-1980

Clams, oysters, and mussels eat plankton filtered from water.

How would clams, oysters, and mussels most likely be affected if the amount of plankton in a large body of water was significantly reduced?

• They would increase in number.

• They would find a new food source.

• They would become prey to other animals.

• They would compete for a limited food source.

The climate in a mountain environment has been changing over a long period of time. The climate is becoming warmer and the amount of rainfall is decreasing. The lower rainfall is also limiting the amount of plant life available as a food source. A species of goat that lives in this environment has had thinning hair over this period of time.

Which of these describes how thinning hair helps the species of goat survive?

• By stopping it from overheating

• By letting it survive on less food

• By reducing how much water it loses

• By allowing it to absorb more sunlight

The papaya mealybug is a pest that poses a threat to many tropical plants. Which fate of the mealybug would result from the inability of the species to reproduce?

• The species would mutate.

• The species would increase.

• The species would become extinct.

• The species would continue to thrive.

The snowshoe hare sheds its fur twice a year. In the summer, the fur of the hare is brown. In the winter, the fur is white.

Which of these statements best explains the advantage of shedding fur?

• Shedding fur keeps the hare clean.

• Shedding fur helps the hare move quickly.

• Shedding fur keeps the hare’s home warm.

• Shedding fur helps the hare blend into its habitat.

Dutch elm disease is a fungal infection of elm trees that usually results in death. The disease has killed millions of North American elm trees that were not resistant to the fungus. Scientists have bred resistant elms by crossing North American species with Asian species that show resistance.

Which of the following best describes how natural selection would promote resistant elm populations once the resistance genes from the Asian species were successfully introduced?

• After encountering elms with resistance genes, fungi would avoid elms and begin to attack other tree species.

• Resistance would spread to all of the mature elms in a population from the few trees that acquired the resistance genes.

• By reproducing with each other, elm trees with resistance genes would create super-resistant elms with twice the number of resistance genes.

• Elm trees with resistance genes would survive and pass on resistance to offspring, while trees without resistance would more likely be killed by the fungus.

A map with contour lines is shown.

Which of the following is the best estimate of the difference in elevation between Black Bear Camp and Eagle Peak?

• 400 m

• 900 m

• 1200 m

• 1500 m

What is the contour interval of the topographic map shown?

• 1000m

• 100m

• 200m

• 50m