Twins produced when a single egg is fertilized are called ______________twins. Twins produced from two eggs ovulated at the same time are called ______________ twins.

A. Monozygotic; dizygotic: Monozygotic twins are identical twins that result from the division of a single fertilized egg. Dizygotic twins, or fraternal twins, result from the fertilization of two separate eggs.

B. Dizygotic; monozygotic: This is the reverse of the correct order. Dizygotic twins come from two eggs, and monozygotic twins come from one egg.

C. Monozygotic; identical: Monozygotic twins are identical, but this choice does not mention dizygotic twins, which makes it incomplete.

D. Dizygotic; nonidentical: While dizygotic twins are nonidentical, this choice does not properly define the types of twins produced by a single egg (monozygotic).

A. Lactate is produced during anaerobic metabolism (when oxygen is scarce) as a byproduct of glycolysis, but it is not the direct product of glycolysis itself.

B. Carbon dioxide is a byproduct of cellular respiration, specifically during the Krebs cycle, not glycolysis.

C. Pyruvate is the end product of glycolysis, where glucose is broken down into two molecules of pyruvate.

D. Acetyl-CoA is formed from pyruvate during the transition step before the Krebs cycle, not directly from glycolysis.