What is the primary mechanism by which heat is transferred from Earth's surface to the atmosphere?

Correct Answer: C

Rationale: Convection is the primary heat transfer mechanism from Earth's surface to the atmosphere. Solar radiation heats the surface (~168 W/m² absorbed), warming air via conduction (~24 W/m²), but convection dominates as warm air rises, transferring heat vertically (~97 W/m² latent + sensible heat, per energy budgets like Trenberth). Radiation (~396 W/m² emitted, ~333 W/m² back via greenhouse) is surface-to-space, not directly to atmosphere. Conduction is minor due to air's low conductivity. Advection moves heat horizontally, not vertically primary. Convection's buoyancy-driven circulation (e.g., thunderstorms) outpaces other modes, making it the key process, per climate models, for atmospheric heating.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: Paramesonephric (Müllerian) ducts, in females, develop into the uterus and upper vagina (A), forming under estrogen influence as the mesonephric ducts regress. Ovaries (B) arise from gonadal ridges (mesoderm), not paramesonephric ducts, which are separate from gamete-forming tissues. Testes (C) and prostate (D) develop in males from mesonephric (Wolffian) ducts under testosterone, while paramesonephric ducts degenerate. A is correct paramesonephric ducts' role in female reproductive tract formation contrasts with the others' distinct embryological pathways.

Correct Answer: A

Rationale: Salivary gland ducts are lined with simple cuboidal epithelium (A), suited for secretion and transport, transitioning to stratified near openings. Simple squamous (B) is for diffusion (e.g., alveoli), not ducts. Stratified squamous (C) protects (e.g., esophagus), not typical here. Transitional (D) is urinary, not salivary. A is correct cuboidal cells' secretory role fits salivary ducts.