What term denotes the presence of two or more cell lines in one individual derived from different persons?

What term denotes the presence of two or more cell lines in one individual derived from different persons?

• A. Blastomere symmetry
• B. Blastocoele
• C. Cleavage stage embryos
• D. Chimerism

Answer: (D)

Chimerism is the presence of two or more genetically distinct cell lines in one individual, each originating from a different person. This can happen when cells from two zygotes fuse early in development, or when someone receives donor tissues such as bone marrow or an organ transplant, leading to a mixture of the host and donor cell lines. Sometimes, fetal cells migrate into the mother during pregnancy, or maternal cells into the fetus, creating microchimerism. The other terms describe embryonic structures or stages rather than genetic mixture from different individuals: blastomere symmetry refers to how embryonic cells divide, the blastocoele is the fluid-filled cavity inside a blastocyst, and cleavage stage embryos describe the early rapid divisions before implantation. None of these denote presence of multiple genetic lineages from different persons.

Chimerism is the presence of two or more genetically distinct cell lines in one individual, each originating from a different person. This can happen when cells from two zygotes fuse early in development, or when someone receives donor tissues such as bone marrow or an organ transplant, leading to a mixture of the host and donor cell lines. Sometimes, fetal cells migrate into the mother during pregnancy, or maternal cells into the fetus, creating microchimerism.

The other terms describe embryonic structures or stages rather than genetic mixture from different individuals: blastomere symmetry refers to how embryonic cells divide, the blastocoele is the fluid-filled cavity inside a blastocyst, and cleavage stage embryos describe the early rapid divisions before implantation. None of these denote presence of multiple genetic lineages from different persons.