Question

Amniocentesis Phenylketonuria Turner's syndrome Pleiotropy Sex cells

Hemophilia separate Sickle cell anemia Protein Huntington's disease

Genetic markers Chorionic villi sampling Meiosis Down's syndrome Klinefelter's syndrome

fill in the blank

1. Nondisjunction happens when chromosomes do not _________ equally during the process of _______. This causes an extra chromosome or missing chromosome in the resulting _________. When a sex cell with an extra or missing a chromosome joins with a 'normal' sex cell - a zygote with either an extra chromosome or a missing chromosome is produced. Many times this will cause a miscarriage, but some conditions can develop because of nondisjunction. ________

is the result of an extra #21 chromosome and can cause some health problems and developmental delays.

XXX is called triple X and is usually nonsymptomatic. XXY is _______ and this person would be a male with some secondary female characteristics.

XO is ______________and is a female that may remain small and have little secondary sexual development.

2. __________is autosomal recessive - a recessive allele is received from each parent. In this disorder, stress causes the red blood cells to 'sickle' causing numerous problems in the body. Fatigue, anemia, enlarged spleen, arthritis, problems in several organs/systems. Sickle cell anemia is a good example of the inheritance pattern called __________.

___________(PKU) is autosomal recessive - must receive recessive allele from both parents. PKU can cause brain damage and learning disabilities if not treated with a special diet low in _________.

________.  is autosomal dominant. Any person that has this disease will have a parent that has had it as well. It is a progressive degenerative disease.The previous diseases are equally common in males and females.

________ is sex-linked recessive (it is on the X chromosome) and is more common in boys than girls. It is a bleeding disorder caused by the inability of the blood to clot properly.

3. There are two tests that can be used to identify a number of genetic disorders that can be identified by chromosomal numbers or abnormalities. ___________ can also be tested for to locate specific faulty genes, and the amniotic fluid can be analyzed to look for metabolic problems.

_________ is the test that has been available longer and has a lower risk of miscarriage. A long needle is inserted into the woman's uterus and some fluid is withdrawn. This test can be done during a window of time after the 15th week.

________ is very similar although it can be less invasive, if the needle is inserted through the v a g i n a rather than the uterine wall. CVS does have a higher risk of miscarriage, but it can be done much earlier - between the 10th and 12th week.

Answer 1

1. Nondisjunction happens when chromosomes do not separate_ equally during the process of _meiosis_. This causes an extra chromosome or missing chromosome in the resulting _sex cells_. When a sex cell with an extra or missing a chromosome joins with a 'normal' sex cell - a zygote with either an extra chromosome or a missing chromosome is produced. Many times this will cause a miscarriage, but some conditions can develop because of nondisjunction. _Down's syndrome_ is the result of an extra #21 chromosome and can cause some health problems and developmental delays.

XXX is called triple X and is usually nonsymptomatic. XXY is _Klinefelter Syndrome_ and this person would be a male with some secondary female characteristics.

XO is _Turner’s Syndrome_and is a female that may remain small and have little secondary sexual development.

2. _Sickle cell anemia__is autosomal recessive - a recessive allele is received from each parent. In this disorder, stress causes the red blood cells to 'sickle' causing numerous problems in the body. Fatigue, anemia, enlarged spleen, arthritis, problems in several organs/systems. Sickle cell anemia is a good example of the inheritance pattern called _Pleiotropy_.

_Phenylketonuria_(PKU) is autosomal recessive - must receive recessive allele from both parents. PKU can cause brain damage and learning disabilities if not treated with a special diet low in _protein_.

_Huntington's disease__.  is autosomal dominant. Any person that has this disease will have a parent that has had it as well. It is a progressive degenerative disease.The previous diseases are equally common in males and females.

Hemophilia_ is sex-linked recessive (it is on the X chromosome) and is more common in boys than girls. It is a bleeding disorder caused by the inability of the blood to clot properly.

3. There are two tests that can be used to identify a number of genetic disorders that can be identified by chromosomal numbers or abnormalities. _Genetic markers_ can also be tested for to locate specific faulty genes, and the amniotic fluid can be analyzed to look for metabolic problems.

_Amniocentesis_ is the test that has been available longer and has a lower risk of miscarriage. A long needle is inserted into the woman's uterus and some fluid is withdrawn. This test can be done during a window of time after the 15th week.

_Chorionic villi sampling_ is very similar although it can be less invasive, if the needle is inserted through the v a g i n a rather than the uterine wall. CVS does have a higher risk of miscarriage, but it can be done much earlier - between the 10th and 12th week.