Aneuploidy vs Polyploidy

Let us know about Aneuploidy vs Polyploidy. Chromosomes are the most important structures in a cell, and they are in the nucleus of a cell. Chromosomes consist of two identical DNA molecules and are called chromatids. These chromatids are concentrated at a point called the centromere. In the cell, chromosomes are present as pairs. These chromosome pairs are identical and are, therefore, called homologous chromosomes.

Every cell in an organism has a specific set of chromosomes, and this is constant for an organism. In humans, there are 23 homologous chromosomes and 22 of them are autosomes, which are not involved in sex determination, and sex. The second pair of chromosomes is called allosomes.

According to two sets of biology, chromosomes are called diploid. Most of the species are diploid and symbolized as 2n. In higher plants, the sporophyte is diploid, and humans are also diploid. Organisms have a set of chromosomes called haploid, and are marked by n.

Some organisms have more than two sets of chromosomes, and are called polyploids. Polyploidy is seen in most plant species, but rare in higher animals. Aneuploidy results from missing or adding of a particular chromosome or part of a chromosome. Both polyploidy and aneuploidy show abnormality of chromosome number.


Reversion of chromosome number by adding or missing a particular chromosome or chromosome set or part of a chromosome is called aneuploidy. Therefore, the chromosomal number is different from that of the wild type of the organism due to the different defects.

According to the difference in chromosome number, there are several types of aneuploidy such as monosomy (2n-1), dioecious (n+1), trisomy (2n+1) and nullisomy (2n-2) where the parent phenotype is 2n. Nuclear differentiation is caused by the failure to separate individual chromosomes from opposite poles, i.e. In mitosis or meiosis, both sister chromatids or homologous chromosomes move to one pole, or in other words, to neither.

Polyploidy occurs when a cell has more than two chromosomes. So it changes the chromosome number in a cell. Polyploidy can often be seen in crop plants including important crop plants but rarely in animals, except in vertebrates and invertebrates.

Many types of polyploidy occur through multiple processes. Autopolyploidy is a type that is formed by the multiplication of the genome of a single species. Autopolyploidy is produced in sexual reproduction during ionosis by non-assembly of homologous chromosomes in metaphase or abnormal cell division in mitosis. Allopolyploidy arises due to the combination of genomes of different species as a hybrid species.

Polyploidy can also be induced by inhibiting cell division using various chemicals such as colchicine.

What is the difference between aneuploidy and polyploidy? – Aneuploidy vs Polyploidy

  • The main difference between aneuploidy and polyploidy is that polyploidy is caused by a change in the chromosome number such as 2n, 3n, 5n, whereas aneuploidy is caused by a specific chromosome or part of a chromosome such as 2n-1 (monosomic).
  • Aneuploidy can be seen in humans as genetic disorders; For example, Tuner syndrome and Down syndrome, while polyploidy can be seen in some human muscle tissue.
  • Aneuploidy is more common in humans, whereas polyploidy is rare in humans
  • Polyploidy can be seen in plants which is more common than aneuploidy.