6-8 JLAB Review Set 2

Some students were building models of solids, liquids, and gases by gluing plastic balls to a sheet of cardboard. Which of their models best shows the particles in a solid?

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According to these data, which material is the poorest electrical conductor?

• Glass

• Steel

• Aluminum

• Pencil lead

Which of these best describes the niche of a lion?

• Parasite

• Prey

• Predator

• Producer

Fifty banded and fifty unbanded snails of the same species were released in an area where the banded snails are easily camouflaged. Which of the following best represents the population of these snails after one year?

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Which of these populations is most likely to increase if the number of grasshoppers decreases?

• Plant

• Frog

• Praying mantis

• Owl

Wherever civilizations have flourished, forests have been destroyed. Hundreds of years ago in England, rivers and seaports began to fill with silt after the forests were destroyed. What caused the silt to fill the seaports?

• Eutrophication

• Succession

• Erosion

• Irrigation

Asexual reproduction involves only one parent. The offspring of this type of reproduction hav

• DNA identical to the DNA of the parent

• DNA that is different from the parent

• One-half of the DNA of the parent

• DNA that is incomplete

A battery is placed inside a flashlight and then the flashlight is turned on. The chemical energy of the battery is changed into all of the following forms of energy except -

• electrical energy

• heat energy

• light energy

• mechanical energy

Fossils are evidence of living things that were alive many, many years ago and often consist of the skeletons of creatures imbedded in rock. Why don't fossils contain the animal's soft tissues, as well?

• Because the soft tissues decayed before the fossil could be formed

• Because the rock breaks down soft tissues

• Because the soft tissues were always eaten by scavengers

• Because the rock always smashed the soft tissues flat

A student wanted to test the hypothesis that adding antifreeze to water lowers the freezing point of water. The student found that pure water froze at 0°C, while the water/antifreeze mixture froze at -20°C. In order to confirm the results, the student should repeat the experiment using -

• a container of a different size

• a different amount of antifreeze

• a different amount of water

• exactly the same set-up as the first experiment