Nondisjunction is the addition or deletion of an entire chromosome. The result could be
autism or downs syndrome
chromosomes fail to separate during cell division
The failure of replicated chromosomes to separate is called nondisjunction. This will cause extra or missing chromosomes in the daughter cells.
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)
Nondisjunction is the failure of homologous chromosomes or chromatids to segregate during mitosis or meisos with the result that one daughter cell has both of a pair of parental chromosomes or chromatids and the other has none. An example is Trisomy 21, which is also called Down's Syndrome. This person has 3 chromosome #21.Nondisjunction of genes occur during meiosis I when homologous chromosomes fail to separate or during meiosis II when there is unequal distribution of chromosomes. This leads to aneuploidy.
Meiosis, specifically during anaphase I and anaphase II. This is known as nondisjunction and it causes aneuploidy, such as trisomy 21
If nondisjunction occurs, abnormal numbers of chromosomes may find their way into gametes, and a disorder of chromosome numbers may result.
chromosomes fail to separate during cell division
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.
nondisjunction
The failure of replicated chromosomes to separate is called nondisjunction. This will cause extra or missing chromosomes in the daughter cells.
If all of the chromosomes fail to separate in meiosis, then nondisjunction can result in a diploid gamete. This is a type of chromosomal mutation. In animals, a zygote produced from the union of a mutated diploid gamete and a normal haploid gamete will have triploidy, which is lethal. In plants, this is not necessarily lethal.
Chromosomes fail to separate during cell division (its in the lesson)
Something called nondisjunction can cause too many chromosomes. Most result in the death of the fetus.
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)
Nondisjunction is the failure of homologous chromosomes or chromatids to segregate during mitosis or meisos with the result that one daughter cell has both of a pair of parental chromosomes or chromatids and the other has none. An example is Trisomy 21, which is also called Down's Syndrome. This person has 3 chromosome #21.Nondisjunction of genes occur during meiosis I when homologous chromosomes fail to separate or during meiosis II when there is unequal distribution of chromosomes. This leads to aneuploidy.
Meiosis, specifically during anaphase I and anaphase II. This is known as nondisjunction and it causes aneuploidy, such as trisomy 21
Nondisjunction