2006-12-03 16:47:36 · 6 answers · asked by lizzie 2 in Science & Mathematics ➔ Biology
1) They may have less of enzyme expression and activity of enzymes encoded by the portion of the chromosome complement that they are missing (haploinsufficiency).
2) Also, they are now more sensitive to genetic defects that may reside on the remaining since they only have one allele (called being haploid instead of the normal diploid situation with 2 copies of chromosomes) for every locus encoded by the chromosome complement that they are missing.
They do not get Down's syndrome. Downs is trisomy 21 (3 copies of chromosome 21 or at least an additional copy of the distal part of the long arm of chromosome 21). It is not fewer copies of any chromosome as suggested by two other answers.
2006-12-03 16:55:10 · answer #1 · answered by surfnscience 2 · 1⤊ 0⤋
Um, hello people... one does not get Down's Syndrome from less chromosomes. That occurs when a person inherits an EXTRA # 21 chromosome. To answer the question, it would really depend on the chromosome that is missing. If it happens to be a sex chromosome, and a female only gets one X chromosome, then she will have Turner's Syndrome. She will usually live a pretty normal life, she just cannot have children as she would be infertile. As for it being any other chromosome, I would think that only the genes on the chromosome present would be expressed in the persons phenotype, either dominant or recessive, as there would be no other alleles to dominate over those genes.
Good Luck!
2006-12-03 17:55:52 · answer #2 · answered by sciteach9 2 · 1⤊ 0⤋
Down syndrome or trisomy 21 (in British English: Down's syndrome) is a genetic condition resulting from the presence of all or part of an extra 21st chromosome. Down syndrome is characterized by a combination of major and minor abnormalities of body structure and function. Among features present in nearly all cases are impairment of learning and physical growth, and a recognizable facial appearance usually identified at birth. It is named after John Langdon Down, the British doctor who first described it in 1866.
2006-12-03 16:55:53 · answer #3 · answered by evets.pilot 2 · 0⤊ 0⤋
The person becomes a down syndrome?
2006-12-03 16:55:28 · answer #4 · answered by Hmmmmm 3 · 0⤊ 1⤋
They are born with Downs Syndrome.
2006-12-03 16:55:02 · answer #5 · answered by jennabeanski 4 · 0⤊ 1⤋
They get down syndrome. That also happens if they have too many or one extra Y or X chomosome.
2006-12-03 16:51:40 · answer #6 · answered by funkucla!!! 3 · 0⤊ 1⤋