Which concept describes embryos in the womb tending to resemble earlier, more primitive forms?

Which concept describes embryos in the womb tending to resemble earlier, more primitive forms?

• A. Embryology
• B. Vestigial organs
• C. Fitness
• D. Selective breeding

Answer: (A)

Embryology is the field that studies how organisms develop from fertilized eggs through their fetal stages, and it includes observations that embryos pass through developmental stages that resemble the adult forms of their ancestors. This pattern—early embryonic stages echoing ancestral forms—has long been discussed as ontogeny recapitulating phylogeny, though modern biology recognizes it as a broader developmental tendency rather than a strict rule. The other options don’t describe a field or concept that accounts for this embryonic similarity: vestigial organs are remnants of structures no longer serving their original function, fitness concerns an organism’s reproductive success, and selective breeding involves human-directed trait changes rather than embryonic development patterns.

Embryology is the field that studies how organisms develop from fertilized eggs through their fetal stages, and it includes observations that embryos pass through developmental stages that resemble the adult forms of their ancestors. This pattern—early embryonic stages echoing ancestral forms—has long been discussed as ontogeny recapitulating phylogeny, though modern biology recognizes it as a broader developmental tendency rather than a strict rule. The other options don’t describe a field or concept that accounts for this embryonic similarity: vestigial organs are remnants of structures no longer serving their original function, fitness concerns an organism’s reproductive success, and selective breeding involves human-directed trait changes rather than embryonic development patterns.