This document discusses the classification, origin, and role of euploids and aneuploids. It defines euploids as variations in chromosome number involving a full set of chromosomes, including monoploidy, diploidy, and polyploidy. Aneuploids are variations involving one or two chromosomes within the diploid set, including hypoploidy and hyperploidy. Polyploidy has played an important role in evolution by creating reproductive barriers and leading to instant speciation. While autopolyploidy has had limited impact, allopolyploidy has been important in the evolution of many crop species. Polyploidy can increase genetic variation and adaptive potential in cancer as well as

1. Euploids and Aneuploids-
classification, origin, induction and role
of polyploidy in evolution
PRESENTED
BY
REEMA RANI HEERA
UNDER THE GUIDANCE OF :
Dr. GAGAN KUMAR PANIGRAHI
REGISTRATION NUMBER : 220705180060
DEPARTMENT OF ZOOLOGY
BRANCH: M. Sc IN ZOOLOGY

2. ●Introduction
●Classification of Euploids and
Aneuploids
● Origin and induction of Euploids and
Aneuploids.
●Role of polyploidy in evolution.
Contents

3. Numerical Chromosomal Aberration :
Each species of an organism has a specific number of chromosomes in its somatic cells.
Alterations in the number of chromosomes from the diploid set is called numerical
chromosomal aberration. It is also known as ploidy.
Ploidy, in genetics, the number of chromosomes occurring in the nucleus of a cell.
There are two types of ploidy :-
1- Euploidy
2- Aneuploidy
1-Euploidy:- is the variation in the chromosome number that occurs due to increase or
decrease of full set of chromosomes.
Monoploidy, diploidy and polyploidy are the types in euploidy.
2:-Aneuploidy:
Variation that involves one or two chromosomes within the diploid set of an organism results in
aneuploidy. It is of two types - hypoploidy and hyperploidy.
Introduction

4. Classification of Euploids and
Aneuploids

7. Role of Polyploidy in Evolution
★The polyploidy has played an important role in evolution of new varieties and species in nature, usually an
evolutionary dead end and a source for evolutionary innovations and species diversification.
★It leads to instantaneous speciation, because a single generation event such as hybridization between two species
with subsequent somatic doubling, or the fusion of introduced gametes is enough to quickly establish barriers that
prevent gene flow between the new polyploidy and the old progenitor species, and can lead to reproductive isolation.
★Autopolyploidy has limited contribution in the evolution of plant species. Some of our present day crops, many forage
grasses and several ornamental plants are polyploids.
★Allopolyploidy has played vital role in the evolution of species. A good number of crop species seem to have evolved
through allopolyploidy. This is evident from the widespread occurrence of allopolyploids in various genera of plants and
their high adaptability in nature.
★Although polyploid organisms , especially plants , abound , the apparent non random long-term establishment of
genome duplications suggests a link with environmental condition .
★Polyploidy or whole-genome duplication (WGD) is widespread in nature, agriculture and aquaculture, normal
physiology, regeneration, aging, and pathology.
★ The biased retention of genes following WGDs offers a unique evolutionary potential to evolve key innovations and to
increase biological complexity in the long term.
★In cancer, WGD is a transient state that promotes aneuploidy, and is responsible for increased genetic variation and
subsequent adaptive potential.

8. REFERENCES
Peer. Y. V., Mizrachi. E and Marchal. K. Nature Reviews Genetics 18, 411-424(2017)
Pavelka, N., Rancati, G., Zhu, J., Bradford, W. D., Saraf, A., Florens, L. & Li, R. (2010).
Aneuploidy confers quantitative proteome changes and phenotypic variation in budding
yeast. Nature, 468(7321), 321-325.
Olga V. Anatskaya and Alexander E. Vinogradov. Feature Papers in Molecular Genetics
and Genomics Int. J. Mol. Sci. 2022.
Gjelsvik, K.J.,Besen-McNally, R.,Losick, V.P. Solving the Polyploid Mystery in Health
and Disease. Trends Genet. 2019.

9. ACKNOWLEDGEMENT
Special thanks to My Subject teacher, Dr.
Gagan kumar Panigrahi School of Applied
Sciences , CUTM, Bhubaneswar.
All the faculty members of Department of
Zoology, School of Applied Science, CUTM,
Bhubaneswar.
Family and Friends.