Which term describes monozygotic twins that are physically connected?

Which term describes monozygotic twins that are physically connected?

• A. Conjoined twins
• B. Dizygotic twins
• C. Monozygotic twins
• D. Polyzogotic twins

Answer: (A)

Conjoined twins describe monozygotic twins that are physically connected. They come from a single fertilized egg, so they are genetically identical, but if the embryo’s division occurs later than usual, the two embryos do not separate completely and remain joined at one or more points. The result is twins who share body parts or organs depending on where they are fused. Dizygotic twins, by contrast, come from two separate eggs and are no more alike than regular siblings, and they are not typically connected. The term polyzygotic is not used to describe connected twins; it relates to multiple eggs being fertilized and does not convey a physical connection. Monozygotic alone means identical twins from one egg, but conjoined specifies the physical linkage.

Conjoined twins describe monozygotic twins that are physically connected. They come from a single fertilized egg, so they are genetically identical, but if the embryo’s division occurs later than usual, the two embryos do not separate completely and remain joined at one or more points. The result is twins who share body parts or organs depending on where they are fused.

Dizygotic twins, by contrast, come from two separate eggs and are no more alike than regular siblings, and they are not typically connected. The term polyzygotic is not used to describe connected twins; it relates to multiple eggs being fertilized and does not convey a physical connection. Monozygotic alone means identical twins from one egg, but conjoined specifies the physical linkage.