TEAS 7 science practice questions

Correct Answer: C

Rationale: Condensation is the process where gas particles release energy, slow down, and come together to form a liquid. This phase change occurs when the temperature of the gas decreases, causing the particles to lose energy and transition into the liquid state. In condensation, the gas loses heat energy, leading to a decrease in kinetic energy, which allows the particles to come closer together and form a liquid. This transformation is commonly observed when water vapor in the air cools down and turns into liquid water droplets, seen as dew or fog. Evaporation (choice A) is the opposite process where a liquid changes into a gas. Boiling (choice B) is the rapid phase change from liquid to gas that occurs at a specific temperature. Sublimation (choice D) is the direct transition of a substance from the solid phase to the gas phase without passing through the liquid phase.

Correct Answer: C

Rationale: The Doppler effect is the perceived change in frequency of a wave due to relative motion between the source of the wave and the observer. This phenomenon is commonly observed with sound waves, where the pitch of a sound appears higher as the source moves towards the observer and lower as the source moves away. Option A is incorrect as the Doppler effect primarily applies to sound waves, not light waves. Option B is incorrect because the Doppler effect is not about the change in wave speed due to medium density but rather a change in perceived frequency. Option D is incorrect as it describes wave bending due to different mediums, which is not the primary concept behind the Doppler effect. Therefore, option C accurately describes the Doppler effect and its application to the shift in frequency of sound waves perceived by an observer.

Correct Answer: B

Rationale: A concave lens is thinner at the center than at the edges, causing light rays to diverge when passing through it. This type of lens is also known as a diverging lens because it causes light rays to spread out. Concave lenses are used in various optical devices to correct vision problems and in scientific instruments to diverge light rays for specific purposes. The other choices are incorrect. A convex lens is thicker at the center and converges light rays, while a plano-convex lens has one flat surface and one convex surface, converging light. Diverging lens is a general term that can refer to concave or plano-concave lenses, but in this context, the specific type being referred to is a concave lens.

Correct Answer: C

Rationale: The lymphatic system and the immune system work closely together to fight infections. The lymphatic system aids the immune system by circulating white blood cells, a crucial component in combating pathogens, throughout the body. This collaboration helps identify and eliminate harmful invaders to maintain the body's health and well-being. Choice A (Respiratory system) is incorrect because while it plays a role in oxygen exchange and removing carbon dioxide, it is not primarily responsible for fighting infections. Choice B (Digestive system) is incorrect as its main functions involve breaking down food and absorbing nutrients, not directly fighting infections. Choice D (Nervous system) is incorrect because its primary role is in transmitting signals throughout the body and controlling bodily functions, not in fighting infections.

Correct Answer: B

Rationale: The skeletal system consists of bones, cartilage, ligaments, and tendons that work together to provide structure, support, protection for internal organs, and facilitate movement. It is responsible for supporting the body's framework and protecting vital organs. The muscular system (option A) consists of muscles that work with the skeletal system to produce movement but does not include bones, cartilage, ligaments, and tendons. The nervous system (option C) is responsible for transmitting signals throughout the body to control movement and other functions. The endocrine system (option D) is a collection of glands that produce hormones to regulate various bodily functions but is not primarily involved in structure, support, and movement as the skeletal system is.