ATI TEAS Science

Correct Answer: D

Rationale: The correct answer is D: Catabolism. 1. Catabolism specifically refers to the process of breaking down large molecules into smaller molecules to release energy. 2. Metabolism (A) is the overall set of chemical reactions that occur in an organism, including anabolism and catabolism. 3. Bioenergetics (B) is the study of energy transformation in living organisms, not specifically the breakdown of molecules. 4. Anabolism (C) is the opposite process of catabolism, involving the building of large molecules from smaller ones, requiring energy input.

Correct Answer: A

Rationale: The correct answer is A: The smallest amount of stimulus required for an individual to feel a sensation. The sensory threshold refers to the minimum level of stimulation needed for an individual to detect a particular sensation. This threshold varies from person to person and can be influenced by factors such as sensitivity and attention. Choice B is incorrect as it specifically relates to feeling pain, which is a different sensory experience. Choice C is incorrect as it refers to a response to a stimulus (movement) rather than the detection of sensation. Choice D is incorrect as it describes the origin of the stimulus rather than the threshold for sensation detection.

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.

Correct Answer: B

Rationale: The correct answer is B: Secondary structure. Secondary structure is defined by the local folds and coils in the protein's polypeptide backbone, such as alpha helices and beta sheets. This level of structure does not involve interactions between different regions of the protein (tertiary) or multiple protein subunits (quaternary). Primary structure (A) refers to the linear sequence of amino acids. Tertiary structure (C) involves the 3D arrangement of secondary structures and other elements in a single polypeptide chain. Quaternary structure (D) pertains to the arrangement of multiple polypeptide subunits in a protein complex.

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.