What is the Difference Between Chimera and Mosaic?

Chimera and mosaic are genetic terms that describe two different scenarios that can occur during the development of an organism. The main differences between them are:

1. Number of zygotes: In chimera, the fusion of two zygotes takes place, while in mosaic, only one zygote participates in the formation of the mosaic embryo.
2. Genetic origin: Chimeras originate from the fusion of two or more genetically distinct zygotes, resulting in an organism with at least four parents. Mosaics, on the other hand, arise from a single zygote and involve the combination of two distinct cell lines within one organism.
3. Genetic changes: Chimeras involve a much larger genetic change than mosaics, as they originate from the fusion of two different zygotes. Mosaics are defined by the presence of two genetically distinct cell lines, but they all arise from a single zygote.
4. Formation: Mosaics are formed due to intrinsic genetic variations caused by processes like somatic mutations, while chimeras are formed from allogenic fusion or grafting.

In summary, chimeras are organisms that result from the fusion of multiple zygotes, leading to a combination of genetic material from different sources, while mosaics are organisms with a combination of genetically distinct cell lines arising from a single zygote.

Comparative Table: Chimera vs Mosaic

Chimera and mosaic are two different genetic combinations that occur during development. Here is a table summarizing the key differences between them:

Chimera and mosaic were initially mythical concepts of genetic combination. However, with the advancement of genetics and molecular biology, it has now been possible to scientifically explain the phenomena of chimerism and mosaicism. Both chimeras and mosaics can bring about genetic mutations and chromosomal aberrations, making them of great scientific interest.