Some students used a globe to model the rotation of Earth. They shaded in Texas on the globe, as shown below. They rotated the globe and observed that Texas was in exactly the same place after each rotation.

The students could rotate the globe quickly or slowly. If the globe could rotate only at the rate that Earth actually rotates, about how long would each complete rotation take?

The caterpillars of monarch butterflies eat milkweed leaves. Milkweed leaves contain sap that is toxic to many animals but not to monarch butterfly caterpillars. This sap makes the monarch butterfly caterpillars toxic to predators and protects them from being eaten.

Which of these is an inherited trait of monarch butterfly caterpillars?

The picture below shows a child standing in a swimming pool.

Why does the lower part of the child appear so much different in size from the upper part?

A student makes a model of the water cycle by using a cup, some water, and plastic wrap. After the student places the model near a sunny window, moisture forms on the inside of the plastic wrap.

What change is the student most likely observing in this model?

The Rio Grande Valley is located at the southern tip of Texas at the end of a long river known as the Rio Grande.

How did the delta at the end of the Rio Grande form?

A student observes that the craters on the moon are different sizes. The student designs an experiment to study the formation of craters. The materials for the experiment are marbles and a pan of flour. The student makes a hypothesis that the size of the craters made on the surface of the flour will depend on the height from which the marble is dropped. Some of the steps in the student’s experiment are described below.

Which of these is most likely Step 3 in the student’s experiment?

A student measures the mass of several substances and records the results in the table below.

What is the difference in grams between the total mass of the liquid substances and the total mass of the solid substances used in the investigation? Be sure to use the correct place value.

The diagram shows the metal posts that are usually found on a battery.

The battery can be connected to a bell and a switch to produce sound. Which statement best explains why there are two metal posts on the battery?

The ocotillo is a desert plant with long, straight branches. Its leaves are small and appear for only a short time after a rain. Most of the time, the branches of the ocotillo do not have leaves. Maple trees grow in areas where water is more abundant than in the desert. Maple leaves can be very large and are present for most months of the year.

Ocotillo plants are better adapted for surviving in the desert than maple trees because the characteristics of ocotillo leaves —

A prickly pear cactus is shown below.

The roots of the prickly pear cactus spread out in a wide underground network. How does this type of root system benefit a prickly pear cactus?

Prairie dogs eat plants and dig underground tunnels. Prairie dog tunnels help break up hard prairie soils, and the animals’ waste adds nutrients to the soil. In the past, large groups of prairie dogs lived in many parts of the U.S. Great Plains, but people have destroyed most of these colonies.

Which of these will most likely happen when prairie dogs are removed from an area?

Most cars have lights, power locks, radios, and other equipment that use electricity. Electric circuits power this equipment. Each circuit has a fuse that completes it. The picture below shows one type of fuse a car may have.

Which of these describes one thing that could happen if the wire in a car fuse burns out?

A student designs an experiment to test the force of a spring using a spring launcher and four spheres with the same diameter but with different masses.

What other piece of equipment would be most useful for this experiment?

Shadows cast by objects change throughout the day. The picture below shows the shadow cast by a tree at 3:00 P.M.

Which picture shows how the tree’s shadow most likely looked at 9:00 A.M.?

A cook uses the ingredients listed below to prepare a meal. 

Which table correctly shows the physical properties of these ingredients when placed in hot water?

The model shows a special glass fiber that is thinner than some metal wires. When light enters one end of the fiber, it moves through the fiber as shown.

After the light leaves the fiber, it travels —

Some facts about birds called cattle egrets are listed below.

Which of these facts best describes how these birds depend on other animals to survive?

Wild Texas hogs, similar to the one shown below, are descended from hogs brought here from other countries.

These wild hogs eat many different kinds of foods, including plants, fungi, and insects. Besides being very destructive to the habitats of other animals, how do wild hogs most likely harm other animals?

Rube Goldberg was an artist who drew cartoons that showed a very complicated way to do a simple task. The picture below shows a cartoon like the ones Goldberg drew.

Which form of energy is used to turn on the switch?