The average female has a _____ percentage of water by weight compared to a male because females typically have more ______ tissue.

Correct Answer: C

Rationale: Females have lower water percentage (~50% vs. males ~60%) due to more adipose tissue less water-rich than muscle (e.g., fat ~10% water, muscle ~75%). Higher water contradicts fat lowers. Muscle increases water opposite. Lower muscle isn't primary adipose key. Adipose's impact distinguishes it, critical for sex differences, unlike muscle or reverse errors.

Correct Answer: B

Rationale: A buffer takes up excess H or OH⁻ e.g., HCO₃⁻ neutralizes (pH stability). Acid donates H not absorbs. Base takes H not OH⁻. Salt is neutral non-buffering. Buffer's dual capacity distinguishes it, key to homeostasis, unlike one-way or neutral substances.

Correct Answer: B

Rationale: Large intestine isn't excretory removes feces, not metabolic waste (e.g., defecation vs. excretion). Kidney excretes urine true. Liver processes urea excretory. Lungs expel COâ‚‚ excretory. Intestine's fecal role distinguishes it, key to excretion definition, unlike waste-excreting organs.

Correct Answer: A

Rationale: Sodium balance hinges on GFR (filtration rate) and Na reabsorption e.g., PCT (65%), aldosterone (distal). GFR/renin ties BP not direct Na . Na /K links aldosterone partial view. None denies control false. GFR/reabsorption synergy distinguishes it, critical for Na homeostasis, unlike partial or null options.

Correct Answer: C

Rationale: Countercurrent exchange concentrates urine Loop of Henle/vasa recta gradient (e.g., ~1200 mOsm medulla). Bicarbonate buffers pH not concentration. Renin-angiotensin regulates BP not urine osmolality. Densification isn't a term false. Countercurrent's gradient distinguishes it, key to urine concentration, unlike buffering or BP systems.