1.
A tuna is an ocean fish that is well adapted to catiching small, fast-moving prey. Which of the following adaptations most helps a tuna swim fast to catch its prey?
Correct Answer
A. Large fins
Explanation
Large fins are an adaptation that helps a tuna swim fast to catch its prey. Fins provide stability and maneuverability in water, allowing the tuna to change direction quickly and swim at high speeds. The large size of the fins increases surface area, which generates more thrust and propels the tuna forward. This adaptation enables the tuna to effectively chase and capture its fast-moving prey in the ocean.
2.
A student hears the sound of a bell. Which of the following carries the sound of the bell to the student?
Correct Answer
D. Vibrating air
Explanation
When a bell is rung, it creates vibrations in the air. These vibrations travel through the air as sound waves and reach the student's ears, allowing them to hear the sound of the bell. Therefore, vibrating air carries the sound of the bell to the student.
3.
A student sorted mineral samples into two groups: dull and shiny. Which of the following properties did the student use to sort the mineral samples into groups?
Correct Answer
C. Luster
Explanation
The student used luster to sort the mineral samples into groups. Luster refers to the appearance or quality of light reflected from the surface of a mineral. Minerals can have different luster properties such as metallic, glassy, dull, or shiny. By observing the luster of the mineral samples, the student was able to categorize them into two groups: dull and shiny.
4.
Approximately how long does Earth take to complete its orbit around the sun?
Correct Answer
C. One year
Explanation
Earth takes approximately one year to complete its orbit around the sun. This is known as a revolution or a full orbit. It is the time it takes for Earth to travel around the sun and return to its starting position. This duration is significant as it determines the length of our calendar year and the change of seasons.
5.
Which of the following statements best explains why magnets usually stick to a refrigerator door?
Correct Answer
B. The refrigerator door contains iron.
Explanation
Magnets usually stick to a refrigerator door because the door contains iron. Iron is a magnetic material, meaning it can be attracted to magnets. Therefore, when a magnet is brought close to the refrigerator door, the iron in the door is attracted to the magnet, causing the magnet to stick to the door. This is why magnets are commonly used to hold things on refrigerator doors.
6.
A squid is an animal that lives in the ocean. It pumps a stream of water out of its body, causing it to move rapidly. Which of the following mechanical systems moves in a way most similar to the squid?
Correct Answer
C. A rocket
Explanation
A rocket moves in a way most similar to a squid. Both a rocket and a squid propel themselves by expelling a fluid (water in the case of a squid, and exhaust gases in the case of a rocket) out of their bodies. This expulsion of fluid creates a reaction force that propels them forward. Similarly, both a rocket and a squid move rapidly due to the force generated by the expulsion of fluid.
7.
Which of the following changes is caused by removing heat?
Correct Answer
D. A liquid changes to a solid
Explanation
When heat is removed from a substance, it causes the molecules to lose energy and slow down. This decrease in energy and motion causes the substance to undergo a phase change from a liquid to a solid. The particles in a liquid have more freedom to move and are less tightly packed compared to a solid. So, when heat is removed, the particles lose energy and become more tightly packed, forming a solid.
8.
Naomi has a pet dog. Which of the following characteristics did the dog most likely inherit from its parents?
Correct Answer
C. The color of its fur
Explanation
The dog most likely inherited the color of its fur from its parents. This is because fur color is a genetic trait that is passed down from one generation to the next. The genes responsible for fur color are present in the dog's parents and are passed on to their offspring. Therefore, it is highly likely that the dog's fur color is determined by the genes inherited from its parents.
9.
Sandra puts some pill bugs into an open box. She covers half the box with a piece of cardboard. She then places the box outside on a summer day, and all the pill bugs move under the cardboard. The pill bugs are most likely responding to which of the following?
Correct Answer
B. Bright light
Explanation
The pill bugs are most likely responding to bright light. Pill bugs are known to be negatively phototactic, meaning they prefer dark or shaded areas. By covering half of the box with a piece of cardboard, Sandra creates a dark area under the cardboard, which attracts the pill bugs to move towards it. This behavior is a natural response to avoid bright light and seek a more suitable environment for the pill bugs.
10.
Heat, light, and sound are all different forms of
Correct Answer
B. Energy.
Explanation
Heat, light, and sound are all forms of energy. Heat is a form of energy that is transferred from one object to another due to a temperature difference. Light is a form of energy that is produced by electromagnetic radiation and enables us to see. Sound is a form of energy that is produced by vibrations and travels through a medium, such as air or water. Therefore, energy is the correct answer as it encompasses all three forms of heat, light, and sound.