How much dietary protein should athletes consume daily?

Correct Answer: C

Rationale: Athletes should consume 1.2-1.7 g protein per kg bodyweight daily, per sports nutrition guidelines (e.g., ACSM), balancing muscle repair, synthesis, and adaptation for training demands (endurance or strength). Below 0.8 g, the sedentary minimum, risks deficiency, impairing recovery. 0.8-1.2 g suits non-athletes or light activity, insufficient for athletic stress. Over 2.0 g, common in bodybuilding, exceeds needs for most, with excess metabolized, not enhancing performance. The 1.2-1.7 g range optimizes nitrogen balance and recovery, distinguishing it as ideal, tailored to athletic workloads unlike lower or excessive intakes.

Correct Answer: B

Rationale: Wrist flexors (e.g., flexor carpi radialis) originate from the medial epicondyle of the humerus, a bony prominence anchoring forearm flexors. Lateral epicondyle hosts extensors (e.g., extensor carpi). Carpals are distal, not origins. Deltoid tuberosity relates to deltoid, not wrist. Medial epicondyle's role distinguishes it, key for wrist flexion leverage.

Correct Answer: C

Rationale: Bacteria, particularly pathogenic ones, use secretion systems like type III to inject soluble proteins into host cells. These effector proteins manipulate host processes disrupting signaling, cytoskeletal structure, or immune responses to facilitate infection. Often part of virulence strategies in pathogens like Salmonella, they differ from receptors, which receive signals, and enzymes, which catalyze reactions, though some effectors have enzymatic activity. Antibodies are host-derived, not bacterial. Effector proteins' role in crossing host membranes and altering cellular function distinguishes them, reflecting their specialized purpose in bacterial pathogenesis and host-pathogen interactions.

Correct Answer: A

Rationale: Solubility of most solids in liquids rises with temperature because higher thermal energy enhances molecular motion, breaking solute-solute bonds and increasing solvent-solute interactions. For example, sugar dissolves better in hot water. Pressure affects gases more than solids, and decreasing temperature typically reduces solubility, as seen in crystallization. Lower pressure has minimal impact. This temperature-driven solubility increase, rooted in thermodynamics, applies broadly to ionic and polar solids, distinguishing it from gas solubility dynamics.

Correct Answer: A

Rationale: Cellular respiration in animals breaks down glucose with oxygen to produce energy. This process glycolysis, Krebs cycle, and electron transport chain yields ATP, the cell's energy currency, powering functions like muscle movement. Oxygen is a reactant, not a product, while RNA and DNA are genetic molecules, not respiration outputs. ATP's role as the direct energy product, formed via oxidative phosphorylation, marks it as the primary outcome, essential for cellular work and distinguishing it from structural or input substances.