7.5CI. The flow of energy in some Australian food chains is modeled in the energy pyramid below.

Based on the model, which consumers would receive the greatest amount of energy captured by the producers in their food chains?A.wedge-tailed eaglesB.chuditchC.ring-tailed opossumsD.eucalyptus trees

7.6A II. Hay is made up of organic compounds. What are the main elements in many organic compounds?

A. helium, carbon, sodiumB. sodium, hydrogen, nitrogenC. carbon, hydrogen, oxygenD. radon, oxygen, helium

III. Based on its chemical formula, which of the following substances is an organic compound?A. Urea, CH4N2OB. Ammonium sulfide, (NH4)2SC. Silane, SiH4D. Sodium chloride, NaCl

7.6BIV. Many processes occur in the digestive system. Which process is best classified as a physical change?

A. saliva converting the starch molecules in crackers into simple sugarsB. digestive enzymes breaking down proteins into smaller fragmentsC. bacteria converting lactose into simple sugars in the intestines

7.7AV. Two boxes and their masses are shown below.

Which of the following situation shows work being done?A. a student is sitting in a chair and holding both boxesB. a student is holding the large box 1 meter above the floorC. a student is standing and holding the small boxD. a student is lifting the small box .5 m from the floor to a table

VI. Four students volunteered to help a librarian move containers of library materials. The graph shows the amount of force used to lift the containers. The numbers in the bars show the mass of each container. The results for each student helper are shown in the table.

Based on this information, which student helper did not do any work on a container?A.Helper WB.Helper XC.Helper Y D.Helper Z

7.8CVII.A student sets up the investigation shown below.

The movement of colored water through the gravel best models - A. condensation of water vaporB. surface runoff of precipitationC. conservation of waterD. pollution of groundwater

7.10B VIII.The food webs below model relationships among the organisms in two ecosystems.

Which ecosystem would be more likely to survive if a disease killed the grasses?

A.the forest ecosystem, because most of the animals can eat other organismsB.the grassland ecosystem, because several predators compete for foodC.the forest ecosystem, because it has three top predatorsD.the grassland ecosystem, because it has many herbivores

7.10CIX. Some students take care of a vegetable garden. When it is time to plant in the spring, the students leave part of

the garden empty in order to observe ecological succession. Which of these will most likely occur first?A. development of topsoilB. growth of weeds and grassesC. growth of trees and shrubsD. development of a stream

7.11CX. 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?A. by increasing the age of the cows that are bredB. by choosing cows that are high milk producersC. by limiting the number of offspring per cowD. by choosing cows that can produce milk after eating the most food

XI. When Charles Darwin visited the Galapagos Islands in the 1800s, he observed many types of organisms that were similar but lived on different islands. The four species of mockingbirds found on the Galapagos Islands are shown below. Each species lives on a different island.

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

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

offspring.

7.11ASome students collected leaf samples. The students used the leaf identification key show below to identify a leaf sample.

XII.Based on the identification key, which type of tree is this sample from?A. GinkgoB. Honey locustC. Horse chestnutD. Black maple

7.12BXIII.When people run long distances, their muscles require increased amounts of oxygen. Which system is

responsible for carrying this oxygen to the muscles?A. nervousB. respiratoryC. digestiveD. circulatory

7.12DXIV.Plants use energy from sunlight, water, and carbon dioxide to produce sugar. Which structure is found only in

plant cells and helps plants capture energy from sunlight?A. vacuoleB. nucleusC. chloroplastD. cell membrane

7.12FXV. In 1838 botanist Matthias Schleiden determined that all plants are composed of cells. In 1839 anatomist Theodor

Schwann proposed that all animals are composed of cells. In 1855 biologist Rudolph Virchow added to Schleiden’s and Schwann’s observations and proposed that all living things are composed of cells. Which statement is also part of Virchow’s cell theory?A. all cells have a cell wallB. all cells arise from pre-existing cellsC. all cells are capable of photosynthesisD. all cells can develop into any other type of cell

7.14BXVI.Certain species of whiptail lizards have only female individuals and no males. These lizards reproduce asexually.

What is one disadvantage of asexual reproduction for these lizards?A. a new population can be established by a single individual in a relatively short period of timeB. all the members of a population are genetically very similar and less able to survive environmental changesC. they are smaller than lizards that reproduce sexuallyD. they are more likely to develop a variety of tail lengths

XVII.The hydra is a very small, simple animal that lives in water. Hydras reproduce asexually by budding, a process in which a bud breaks off an adult hydra and float away.

Which of the following best describes a hydra bud?A.a hydra bud contains genetic material from its two parentsB.a hydra bud is genetically identical to the parent hydraC.a hydra bud has different mutations than the parent hydraD.a hydra bud has half as much genetic material as the parent hydra

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