NU 545 UNIT 7 | LATEST UPDATED| REAL EXAM
QUESTIONS AND ANSWERS | 100% RATED
CORRECT | 100% VERFIED | ALREADY GRADED A+
Save
Terms in this set (79)
,Describe the specific chromosomal The most well known aneuploidy (those that do not
abnormality responsible for Down contain a multiple of 23 chromosomes) in an
Syndrome autosome is trisomy of the 21st chromosome. J.
Langdon Down 1st described the the disease in 1866.
Down syndrome is seen in 1 in 800 births. IQ's
between 25 and 70. Facial features: low nasal bridge,
epicentral folds, protruding tongue, and flat low set
ears. Congenital heart defects in 1/3 to 1/2 of live
born children. Decreased ability to fight respiratory
conditions and an increased susceptibility to
leukemia. By age 40 symptoms resembling
Alzheimer develop. 97% of Down Syndrome's cases
are caused by nondisjunction during the formation
of one of the parent's gametes or during early
embryonic development. 3% from translocations.
Risk increases with maternal age.
Causes of mental retardation. Chromosomal abnormalities.
,What gene abnormality causes cystic Like autosomal dominant diseases, those caused by
fibrosis? autosomal recessive alleles are rare in populations,
although the number of carriers for recessive
diseases can be high. The most common lethal
recessive disease in white children, cystic fibrosis,
occurs in about 1 in 2500 births. Approximately 1 in
25 whites carries one copy of an allele that can
cause cystic fibrosis (see Chapter 36). Because an
individual must be homozygous for a recessive allele
to express thedisease, the carriers are
phenotypically normal. Because most recessive
alleles are maintained innormal carriers, they are
able to survive in the population from one
generation to the next. As with many autosomal
dominant diseases, many autosomal recessive
diseases are characterized by delayed age of onset,
incomplete penetrance, and variable expressivity.
, How is a recessive gene inherited? Autosomal recessive diseases occur when both
parents are carriers of the same disease and their
child inherits an altered gene from each of them.
Children of carrier parents have:A 25% chance of
inheriting two altered genes and developing the
disease.
QUESTIONS AND ANSWERS | 100% RATED
CORRECT | 100% VERFIED | ALREADY GRADED A+
Save
Terms in this set (79)
,Describe the specific chromosomal The most well known aneuploidy (those that do not
abnormality responsible for Down contain a multiple of 23 chromosomes) in an
Syndrome autosome is trisomy of the 21st chromosome. J.
Langdon Down 1st described the the disease in 1866.
Down syndrome is seen in 1 in 800 births. IQ's
between 25 and 70. Facial features: low nasal bridge,
epicentral folds, protruding tongue, and flat low set
ears. Congenital heart defects in 1/3 to 1/2 of live
born children. Decreased ability to fight respiratory
conditions and an increased susceptibility to
leukemia. By age 40 symptoms resembling
Alzheimer develop. 97% of Down Syndrome's cases
are caused by nondisjunction during the formation
of one of the parent's gametes or during early
embryonic development. 3% from translocations.
Risk increases with maternal age.
Causes of mental retardation. Chromosomal abnormalities.
,What gene abnormality causes cystic Like autosomal dominant diseases, those caused by
fibrosis? autosomal recessive alleles are rare in populations,
although the number of carriers for recessive
diseases can be high. The most common lethal
recessive disease in white children, cystic fibrosis,
occurs in about 1 in 2500 births. Approximately 1 in
25 whites carries one copy of an allele that can
cause cystic fibrosis (see Chapter 36). Because an
individual must be homozygous for a recessive allele
to express thedisease, the carriers are
phenotypically normal. Because most recessive
alleles are maintained innormal carriers, they are
able to survive in the population from one
generation to the next. As with many autosomal
dominant diseases, many autosomal recessive
diseases are characterized by delayed age of onset,
incomplete penetrance, and variable expressivity.
, How is a recessive gene inherited? Autosomal recessive diseases occur when both
parents are carriers of the same disease and their
child inherits an altered gene from each of them.
Children of carrier parents have:A 25% chance of
inheriting two altered genes and developing the
disease.
