Differentiated cells in a developing embryo derive from

Correct Answer: B

Rationale: Ectoderm, mesoderm, and endoderm are the three germ layers in an embryo from which all differentiated cells arise.

Correct Answer: A

Rationale: A compound consists of different elements (atoms) chemically bonded, unlike elements with one atom type.

Correct Answer: B

Rationale: Molecular weight is the sum of atomic weights of all atoms in a molecule.

Correct Answer: B

Rationale: The nucleus is the largest organelle, housing DNA and controlling cell activities.

Correct Answer: C

Rationale: Central dogma: DNA is transcribed to mRNA, which is translated to protein.