A diploid organism that has some polyploid cells is exhibiting somatic polyploidy, a form of genomic mosaicism in which most body cells contain two complete chromosome sets while a subset contains three or more. This condition may result from normal developmental programs, such as endoreduplication in specialized tissues, or from errors during the cell cycle. It is not the same as an organism being entirely polyploid, and the biological consequences depend on which tissues contain the extra chromosome sets and how those cells behave Most people skip this — try not to..
Quick note before moving on And that's really what it comes down to..
Introduction: What Does This Pattern Mean?
A typical diploid organism has cells with two chromosome sets, represented as 2n: one inherited from each parent. Because of that, if every cell in the organism contained additional complete sets, the organism itself would be described as triploid, tetraploid, or otherwise polyploid. On the flip side, when only certain somatic cells have extra chromosome sets, the organism is best described as polyploid mosaic.
The key distinction is between the ploidy of the whole organism and the ploidy of individual cells. Day to day, a plant may have mostly diploid leaves but tetraploid sectors in its stem. An animal may produce normally diploid blood and skin cells while some liver, heart, or blood-forming cells become polyploid. These cells can coexist because they arise from a diploid ancestor through changes in DNA replication, chromosome separation, or cell division And that's really what it comes down to..
Main Types of Somatic Polyploidy
Somatic polyploidy can arise through several related mechanisms. The most important are described below.
1. Endoreduplication
**Endoreduplication
