0
Down's Syndrome is caused due to the presence of an extra 21st chromosome, resulting in 3 sets of 21st chromosome instead of just 2. This is because during Anaphase II of Meiosis II non-disjunction occurs and instead of one 21st chromosome going into each gamete, both go into one of the gametes and none goes into the other. When a normal gamete fuses with the gamete with an extra21st chromosome, it forms a zygote with 3 sets of 21st chromosome instead of 2 and that is known as Down's Syndrome.
Wiki User
∙ 13y ago
Add your answer:
Earn +20 pts
If a child is born with down syndrome when did the mutation occur?
During meiosis
Which stage of meiosis causes Down syndrome?
Mistakes in meiosis may cause Down syndrome. The error happens when the chromosomes segregate into the gametes. The egg or sperm may have too many or too few chromosomes. Down syndrome has an extra chromosome in the 21st pair.
Down Syndrome most often occurs when-?
Down Syndrome often occurs when chromosomes fail to separate properly during meiosis.
What is a genetic condition that can result when chromosomes don't separate correctly during meiosis?
Trisomy 21 (Down's syndrome), Turner's syndrome (XO), and Klinefelter's syndrome (XXY) are a few examples of genetic disorders that can result when chromosomes don't separate correctly during meiosis.
What is the failure of chromosome pairs to separate properly during meiosis?
Nondisjunction
Is down syndrome a single gene disorder?
People with Down syndrome have an extra copy of chromosome 21 in every cell. Down syndrome most often occurs when chromosomes fail to separate properly during meiosis, when sex cells form. Hope this helps!!
How are cells of a person with Down syndrome different from those of a person without the disorder?
In Down syndrome, a person's cells have an extra copy of chromosome 21. In other words, instead of a pair of chromosomes, a person with Down syndrome has three of that chromosome. Down syndrome most often occurs when chromosomes fail to separate properly during meiosis. People with Down syndrome have a degree of mental retardation. Heart defects are also common, but can be treated.
Can medication for gallstones during pregnancy cause Down syndrome?
See the Related Link to a very good FAQ on the causes of Down syndrome.
What effects does nondisjunction have on the body if it occurs during mitosis What problems can an individual have if they have nondisjunction in somatic cells?
Autosomal nondisjunction is the most prolific cause of trisomy 21, or down syndrome, a defect that usually occurs during meiosis 1, but can occur during 2 as well.
Does a nondisjunction cause down syndrome?
During meiosis, chromosomes are separated equally. When they are not separated equally - this is known as non-disjunction - the gametes end up with either an extra chromatid or no chromatid. In Down syndrome the offspring carries an extra chromatid in Chromosome 21, aka Trisomy 21.
How are the cells of a person with Down syndrome different from those of a person without Down syndrome?
In Down syndrome, a person's cells have an extra copy of chromosome 21. In other words, instead of a pair of chromosomes, a person with down syndrome has three of that chromosome. Down syndrome most often occurs when chromosomes fail to separate properly during meiosis. People with down syndrome have a degree of mental retardation. Heart defects are also common, but can be treated.
Too much Y choromosome in urine during pregnancy?
Can cause down syndrome
