Which statement best differentiates exocrine and endocrine glands?

• A. Exocrine glands contain ducts and empty their products onto a surface; endocrine glands lack ducts and release into surrounding tissue to reach the blood.
• B. Exocrine glands are unicellular; endocrine glands are multicellular.
• C. Exocrine glands release hormones into the bloodstream; endocrine glands release secretions to surfaces.
• D. Exocrine glands are only in skin; endocrine glands are only in pancreas.

Answer: (C)

The key idea is how secretions leave the gland and where they act. Exocrine glands have ducts and release their products onto epithelial surfaces or into body cavities (for example, sweat onto skin or enzymes into the digestive tract). Endocrine glands lack ducts and secrete hormones into the surrounding interstitial fluid, from which they enter the bloodstream to reach distant targets. This contrasts with statements that swap these routes or rely on examples that aren’t universal (some glands can have mixed functions, like the pancreas). So the correct distinction is: duct-bearing glands release onto surfaces, while ductless glands release hormones into the blood.