Staar Category 4 Science

Leopards eat baboons and impalas in a terrestrial ecosystem. What prediction can be made if the baboon population begins to decrease because of disease?

• The leopards population will increase.

• The hawk population will increase.

• The impala population will decrease.

• The scorpion population will decrease.

What relationship exists between seed-eating birds and grass?

• Predator/host

• Consumer/Producer

• Parasite/host

• Consumer/consumer

In the marine food web, which organisms are considered predators to more than one organism?

• Krill and phytoplankton

• Squid and zoopankton

• Leopard seal and cod

• Penguin and elephant seal

The Center for Disease Control publishes articles explaining the causes of seasonal West Nile virus. Research proves mosquitoes in freshwater ecosystems spread the disease to humans and other organisms. How do mosquitoes transmit the West Nile virus to other organisms?

• Mosquitoes transmit the virus when they land on the skin of an organism.

• Mosquitoes transmit the virus as parasites which feed on the blood of host organisms and inject the virus during feeding.

• Mosquitoes transmit the virus by preying on organisms and spreading the virus on contact.

• Mosquitoes transmit the virus as hosts who feed on the blood of organisms and inject the virus during feeding.

Hawks are predators to small organisms such as snakes, rabbits, and mice. What is a possible result of adding a hawk to this ecosystem?

• The rabbit population will increase.

• The grass population will increase.

• The cougar population will increase.

• All of the above.

How might the information most directly affect the ocean?

• Fish populations increase along the coasts.

• Runoff from coastal cities carries more pollutants.

• More artificial reefs appear off the coasts.

• Shark attacks decrease.

Artificial reefs are man-made structures that provide surfaces for algae and other invertebrates such as barnacles to attach. In turn, these reefs attract fish and larger predators. Which statement describes a positive effect of artificial reefs on the ocean system?

• These created habitats could increase the local shark population, which might increase the number of shark attacks on humans.

• The increased fish population may lead to overfishing on the coasts.

• Materials within the artificial reef could contain toxins that damage the marine ecosystem.

• There is an increase in biodiversity in the ocean system

For what abiotic factor are the plants most likely competing?

• Water

• Soil composition

• Sunlight

• Wind to spread seeds

Scientists study an ecosystem devastated by drought and observe the interactions of organisms in relation to food, light, water, and mates. Which hypothesis statement relates to the investigation?

• If available resources increase, then competition will increase.

• If the drought continues, then competition will decrease.

• If available resources decrease, then competition will increase.

• If available resources remain constant, then competition will decrease.

Four students are conducting a laboratory investigation about competition for resources. They are given different kitchen utensils and various food resources. How would these materials model competition for resources?

• Every utensil can pick up the food resources equally.

• Utensils are adapted to gather a variety of food resources, causing some organisms to benefit from more than one food source.

• The variety of materials available does not model competition.

• All of the above.