ATI TEAS Science

Correct Answer: A

Rationale: Platelets are responsible for clotting by forming a plug at the site of injury. They release chemicals to initiate clotting cascades. Red blood cells transport oxygen, antigens are markers on cells, and plasma cells are involved in immune response, not clotting. Therefore, the correct answer is A.

Correct Answer: D

Rationale: The correct answer is D because bones are resistant to shattering due to the intricate balance of minerals like calcium and phosphorus, along with collagen fibers. Calcium salts alone (choice A) only provide hardness, not flexibility. Collagen fibers (choice B) provide strength but not hardness. Bone marrow and blood vessels (choice C) support bone health but don't contribute directly to resistance to shattering. The combination of minerals and collagen fibers in choice D provides both hardness and flexibility, making bones resistant to shattering.

Correct Answer: A

Rationale: The correct answer is A because all types of muscle tissue share the properties of being contractile (ability to contract), excitable (responsive to stimuli), elastic (ability to return to original shape), and extensible (ability to stretch). Choice B is incorrect because voluntary is not a shared property of all muscle tissues. Choice C is incorrect because voluntary is not a shared property of all muscle tissues. Choice D is incorrect because voluntary is not a shared property of all muscle tissues.

Correct Answer: A

Rationale: The correct answer is A because in a primary immune response, the first event is the recognition and phagocytosis of pathogens by macrophages. This is crucial for initiating the immune response by presenting antigens to T cells. Neutrophils (choice B) are important in later stages as part of the innate immune response. B lymphocytes (choice C) produce antibodies later in the response. Helper T cells (choice D) are activated by the antigens presented by macrophages and play a role in coordinating the immune response but are not the first event.

Correct Answer: C

Rationale: The correct answer is C: The glomerulus. The glomerulus is a cluster of capillaries within the Bowman's capsule where blood filtration occurs. It functions as the main filter of the blood entering the kidney by allowing small molecules like water, glucose, and wastes to pass through while retaining larger molecules like proteins and blood cells. The Loop of Henle is responsible for water reabsorption, not blood filtration. The Bowman's capsule is the initial structure where the glomerulus is located, but it is not the main filter. The nephron is the functional unit of the kidney composed of the glomerulus, Bowman's capsule, and tubules, so it encompasses the other structures mentioned.