0
What evidence suggest that Down syndrome is more often the result of non-disjunction during oogenesis rather than during spermatogenesis?
Beiziers
One decent piece of evidence is that the incidence of newborns with Down's increases exponentially with the age of the mother. Once a woman reaches 45 years of age the chance of her having a child with Down's becomes 1:30, as opposed to 1:1667 if the woman is 20. No correlation like this has been found in the age of the father.
The increase in the incidence of Down's with mothers age is likely because all of the eggs a female has are with her from birth. They are trapped in one of the stages of the cell cycle (prophase 1 of meiosis). The longer the woman waits before becoming pregnant the older of an egg cell she is using. These older cells have been trapped in prophase 1 for many years. This, in some way, leads to an increase in the rate of non-dysjunction events (failure of 2 chromosomes to separate) and thus, an increase in trisomy 21.
Wiki User
∙ 12y ago
Add your answer:
Earn +20 pts
What is a chromosomal disorder that could result from nondisjunction?
Disorders, such as Down's Syndrome, are caused by nondisjunction.
The faillure of chromosomes to separate during meiosis is called?
Its called disconjunction. Sometimes it is so bad that they have a miscarriage or the following happens:Trisomy (extra chromosomeso have 47 chromosomes instead of 46)Down's syndrome (andextra number 21 chromosome)Klinefelter's syndrome (males with an extra X chromosome...XXY)
Triple X syndrome occurs because of whAT?
Nondisjunction
What is nondisjunction in chromosomes and what is the result?
Nondisjunction is the addition or deletion of an entire chromosome. The result could be autism or downs syndrome
What is the cause of xyy syndrome and genetics?
Nondisjunction in Meiosis 2
Are there carrier forms of xxx syndrome?
no there r no carrier forms for triple x syndrome. this is just a nondisjunction during meiosis of gametogenesis. this can happen with either spermatogenesis or ovariogenesis
What disorder is caused by nondisjunction in males?
kleinfelters syndrome
What is a chromosomal disorder that could result from nondisjunction?
Disorders, such as Down's Syndrome, are caused by nondisjunction.
The faillure of chromosomes to separate during meiosis is called?
Its called disconjunction. Sometimes it is so bad that they have a miscarriage or the following happens:Trisomy (extra chromosomeso have 47 chromosomes instead of 46)Down's syndrome (andextra number 21 chromosome)Klinefelter's syndrome (males with an extra X chromosome...XXY)
The process that result in Down syndrome is called?
Nondisjunction
What Triple x syndrome occurs because?
Nondisjunction
Triple X syndrome occurs because of whAT?
Nondisjunction
In Jacob syndrome did the nondisjunction occur in the mother or father?
Jacob syndrome, 49XYY, has to occur as a result of nondisjunction in the father. The Jacob Syndrome male would have received the X chromosome from his mother, and both Y chromosomes from the father (since the Y chromosomes can not possibly have come from the mother). Jacob Syndrome can be the result of nondisjunction in meiosis.
What chromosome is associated with patau syndrome?
nondisjunction
Is fragile x syndrome a result of nondisjunction during meiosis?
yes . it is . nondisjunction is takes place during meiosis.
What is nondisjunction in chromosomes and what is the result?
Nondisjunction is the addition or deletion of an entire chromosome. The result could be autism or downs syndrome
What is the genetic event that results in Turner syndrome XO?
nondisjunction
