ATI TEAS Practice Science Test

Correct Answer: B

Rationale: The correct answer is B: Ribcage. The ribcage is a bony structure that surrounds and protects the lungs. It consists of ribs, sternum, and thoracic vertebrae, forming a protective cage around the vital organs in the thoracic cavity. The ribs provide a barrier against external forces and help maintain the shape and integrity of the lungs. The other choices are incorrect because the femur is a bone in the leg, the scapula is a bone in the shoulder, and the skull protects the brain, not the lungs.

Correct Answer: A

Rationale: The correct answer is A: Diffusion. Gas exchange in the respiratory system occurs through diffusion, where oxygen moves from the alveoli in the lungs to the blood and carbon dioxide moves from the blood to the alveoli. This process is driven by a concentration gradient, allowing for the exchange of gases between the air and blood. Exhalation (choice B) is the process of expelling air from the lungs, not the mechanism of gas exchange. Inspiration (choice C) is the process of inhaling air into the lungs, but it is not directly involved in gas exchange. Ventilation (choice D) refers to the movement of air into and out of the lungs and is necessary for gas exchange to occur but is not the actual mechanism of gas exchange itself.

Correct Answer: C

Rationale: The correct answer is C: Shaft. The shaft is the portion of the hair that is visible above the skin's surface and is not attached to the follicle. The bulb (A) is the base of the hair follicle where the hair root (B) is located and is attached to the follicle. The strand (D) refers to the entire hair structure, including the bulb, root, and shaft. Therefore, the shaft is the only part that is not physically connected to the follicle.

Correct Answer: B

Rationale: The correct answer is B (18). Ossification at the growth plate occurs during adolescence when bones undergo rapid growth and development. At around age 18, the growth plates begin to close as bone growth slows down, leading to ossification replacing cartilage. At age 5 (A), the growth plates are still actively contributing to bone growth. At age 42 (C) and 91 (D), ossification is more likely related to aging processes and repair rather than growth plate replacement.

Correct Answer: A

Rationale: The correct answer is A: Artificial/active immunity. The MMR vaccine provides artificial immunity because it is a vaccine created in a laboratory rather than acquired naturally. It induces active immunity by stimulating the body to produce its antibodies against measles, mumps, and rubella. This type of immunity is long-lasting and provides protection by training the immune system to recognize and fight off these diseases in the future. Choice B (Artificial/passive) is incorrect because passive immunity involves receiving pre-formed antibodies rather than activating the immune system to produce its antibodies, which is the case with the MMR vaccine. Choice C (Natural/active) is incorrect because natural immunity is acquired through exposure to the actual disease, not through vaccination. Choice D (Natural/passive) is incorrect because natural passive immunity is passed from mother to baby through breast milk or placenta, not through vaccination.