Question

Aneuploidy is often more detrimental than polyploidy. Explain the difference between these two conditions and give one example why thisstatement is true

Answer 1

Anueploidy and polyploidy both conditions appears due to changes in number of chromosome.

Aneuploidy occurs when changes come in a single chromosome either by addition or deletion but never changes come in chromosomal pair. If deletion occurs it is called hypoaneuploid changes whereas addition causes hyperaneupliod changes.

Suppose chromosome no is 2n

If condition is hyperaneuploid it gives 2n+1 : trisomy

E.g. Trisomy 21 means chromosome number 21 is getting one extra chromosome.

Most commonly this alterations found in animals : trisomy 21 condition is called Down syndrome

Trisomy 18 is Edward syndrome.

Tetrasomy(2n+2) , Double trisomy (2n+1+1) could also appear.

If condition is hypoaneuploid e.g. monosomy (2n-1) it is called turner syndrome where one copy of x chromosome is deleted.

Polyploidy means changes in chromosome number in sets. From 2n condition it changes to 3n (triploidy) , 4n (tetraploidy) means from 2 set of chromosome 3 set/ 4 set conditions could originates. If this extra chromosome belongs to same species, called autopolyploidy . In case of allopolypliody extra set of chromosome belongs to different species.

Most commonly this situation appears in plants and produce hybrid fruit but not found in animals because plant can tolerate one extra set of chromosome but in case of animals this is lethal condition. So anueploidy is more detrimental.