8th Science Category 4

Which of the following is an  example of a biotic factor.

• grass
• water
• elevation
• rocks

During the Industrial Revolution, coal-burning factories produced black soot that covered the trees and killed the lichen near cities. In these areas the number of dark peppered moths increased, while the number of light peppered moths decreased. What led to this change?

• The soot covered trees camoflaged the dark moths.
• The dark moths preyed on the light moths.
• Bird populations increased in areas near factories.
• The dark moths laid fewer eggs.

A Cross Timbers rancher is concerned about competition between the ranch animals and deer. Based on the graph, which animals compete for the most food with the white-tailed deer?

• Cattle that eat grass and feed.
• Goats that eat weeds and shrubs.
• Turkeys that eat seeds and fruit.
• Hogs that eat fruit, seeds, and feed.

These species are very similar, but the Hood mockingbird has a longer beak than the other 3 species. Which of the following best explains this difference?

• The Hood mockingbird needs a longer beak for defense against predators.
• The Hood mockingbird originated from a different type of bird than the other species.
• The Hood mockingbird's longer beak is an adaptation to the available food.
• The Hood mockingbird's beak stretched to reach its food, and the longer beak was passed down to its offspring.

Which of these correctly describes a relationship between organisms in the soil food web?

• Protozoa get nutrients from small arthropods.
• Mammals are predators of birds.
• Nematodes prey on arthropods.
• Bacteria get nutrients from organic matter.

The amount of salt water in Galveston Bay estuary changes with the tides. Sometimes the water is mostly freshwater, and sometimes it is mixed with saltwater. Various plant species live in this environment and provide a habitat for other organisms. To be successful here, a plant species must have an adaptation that allows it to-

• produce large amounts of food
• absorb large amounts of water
• store excess gases
• filter excess salt

When people run long distances, their muscles require increased amounts of oxygen. Which system is responsible for carrying this oxygen to the muscles?

• Nervous
• Respiratory
• Digestive
• Circulatory

At which temperature range will there be the most competition for space among these fish species?

• 5^o to 10^oC
• 10^o to 15^oC
• 15^o to 20^oC
• 25^o to 30^oC

Some dairy farmers want to increase the amount of milk produced by their cows. How can the farmers use selective breeding to increase milk production?

• By increasing the age of the cows that are bred
• By choosing cows that are high milk producers
• By limiting the number of offspring per cow
• By choosing cows that can produce milk after eating the most food