why are chromosomal typically more severe than allelic?
what is the cause of at least 2 chromosomal disorders?
2007-01-21 09:30:13 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Biology
An allele is basically a variation of one particular gene. So an allelic abnormality only involves a single gene.
A chromosome contains thousands of genes. Since a chromosomal abnormality affects an entire chromosome, or a large portion of a chromosome, it therefore affects large numbers of genes.
This would be like the difference between an error in one paragraph of a book versus an error in an entire chapter.
Some chromosomal disorders:
Down Syndrome: the person has an extra copy of chromosome 21.
Cri du Chat Syndrome: the person has lost a portion of the short arm of chromosome 5.
2007-01-21 09:42:48 · answer #1 · answered by Nicole B 5 · 2⤊ 0⤋