Name: Sex Determination (Drosophila melanogaster)
Uploaded: 2019-07-19
Duration: 7 min 20 s
Description: Drosophila melanogaster or the common fruit fly has contributed a lot to genetics. One of them is its sex determination system with more than five types of s...

Question

Distinguish between Down syndrome and Turner syndrome.

Accepted Answer

The differences between Down Syndrome and Turner syndrome are:

Characteristics Down Syndrome Turner syndrome

Scientist This abnormality is discovered by Down. This was first described by H. H. Turner (1938).

Chromosome The most affected person has an extra copy of chromosome 21 i.e., trisomy (2n + 1) of this chromosome. In the human chromosome complement of 44 autosomes plus a single X produces a condition known as Turner syndrome, represented as XO, so this is the monosomic (2n-1) of the X chromosome.

Caused by Down syndrome is caused by trisomy (2n + 1) of chromosome 21; that means there is the presence of an extra chromosome 21 along with normal diploid (2n) chromosome complement. The cause of Turner syndrome is the chromosomal abnormality with regard to the X chromosome of a human.

Produced by The trisomy (2n+ 1) of chromosome 21 may be produced by the non-disjunction of chromosome 21 in a parent who is chromosomally normal. The monosomic (2n-1) type of aneuploidy of the X chromosome is produced with 22 pairs of autosomes and XO condition of sex chromosome i.e., a total of 45 chromosomes.

Distinguish between Down syndrome and Turner syndrome.

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