Cri-du-chat syndrome is associated with
|A)||a missing chromosome number 5.|
|B)||an additional chromosome number 5.|
|C)||a deletion of the long arm of chromosome number 5.|
|D)||a deletion of the short arm of chromosome number 5.|
Approximately ____ percentage of spontaneous abortions result from extra or missing chromosomes.
The most common autosomal aneuploid is
A (an)____ chromosome has its centromere near a tip so that it has one long arm and one very short arm.
|D)||none of the above|
In a (an)____, the short arm of two acrocentric chromosomes break, and the long arms join, forming an unusual, long chromosome.
An individual with two normal sets of autosomes and a single X chromosome has
This structure emanates from the centromere and contacts the spindle fibers during mitosis:
Prenatal diagnostic techniques that obtain fetal chromosomes include all but
|B)||fetal cell sorting.|
|C)||chorionic villus sampling.|
|D)||fluorescence in situ hybridization.|
When chromatids divide along the wrong plane, structures with identical arms called ____ are formed.
In nondisjunction, which parent leads to the sex chromosome aneuploid XYY?
____ contains protein-encoding genes.
Our closest relative, according to karyotypes is the
An individual with the chromosomal description 45, X would be a
|B)||female with Turner syndrome.|
|C)||male with Klinefelter syndrome.|
|D)||cannot be determined.|
Heterochromatic regions at the ends of chromosomes are called
The schematic map of a chromosome is called a (an)
A triploid human karyotype has how many chromosomes?
Nondisjunction of chromosome 21 during meiosis II in human females can result in all of the following chromosome complements in a zygote except (assume the oocyte is fertilized by a sperm with a normal chromosome set)
|A)||no chromosome 21.|
|B)||euploid for chromosome 21.|
|C)||monosomic for chromosome 21.|
|D)||trisomic for chromosome 21.|
About 90% of trisomy 21 Down conceptions are due to nondisjunction during
|A)||meiosis I in the female.|
|B)||meiosis II in the female.|
|C)||meiosis I in the male.|
|D)||meiosis II in the male.|
Consider the following normal sequence of genes: a b c d e f g h. The sequence a b f e d c g h represents a (an)
Which of the following karyotypes is not possible in the offspring of a translocation carrier (involving chromosomes 14 and 21) and a normal individual.
|A)||deficient 14 or deficient 21|
|C)||translocation Down syndrome|
|D)||all are possible outcomes|
A couple seeks testing and counseling after they have a child with cystic fibrosis. Testing reveals that the mother is a carrier, but the father is not. How can these results be explained?
|A)||the man tested is not the biological father|
|B)||a mutation altered the child's normal allele|
|C)||uniparental disomy (from the mother)|
|D)||all are possible explanations, additional testing is needed|
Which of the following cell types is not used to examine chromosomes?
|A)||white blood cells|
|B)||bone marrow cells|
|C)||red blood cells|
|D)||all of the above can be used|
How many chromosomes does a person with Edward syndrome have?
All of the following aneuploids can result from female nondisjunction except
Alagille syndrome results from a (an)