Ease Into Prep with an OAT^® Question of the Day

The correct answer is B.

Stop: The answers are structures associated with embryonic and fetal development.

Think: This question asks which germ layer of the embryo is associated with esophageal lining development. Remember the Kaplan mnemonics: "attracto-derm", "means-o-derm" and linings of "endernal organs".

Predict: The esophageal lining is the lining of an "endernal" organ, hence endoderm.

Match: (B) is correct.

Answers (A) and (C) are germ layers of the embryo, but do not give rise to the lining of the esophagus. The ectoderm develops into structures such as the nervous system, epidermis, lens of the eye, tooth enamel, and the inner ear. The mesoderm develops into structures such as bones, muscle, kidneys, circulatory system, and the gonads.

Answers (D) and (E) are not germ layers of the embryo, and the placenta (E) is not part of the embryo.