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1 | |
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. |
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2 | |
Approximately ____ percentage of spontaneous abortions result from extra or missing chromosomes. |
| | A) | 10 |
| | B) | 25 |
| | C) | 50 |
| | D) | 75 |
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3 | |
The most common autosomal aneuploid is |
| | A) | trisomy 13. |
| | B) | trisomy 15. |
| | C) | trisomy 18. |
| | D) | trisomy 21. |
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4 | |
A (an)____ chromosome has its centromere near a tip so that it has one long arm and one very short arm. |
| | A) | metacentric |
| | B) | submetacentric |
| | C) | acrocentric |
| | D) | none of the above |
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5 | |
In a (an)____, the short arm of two acrocentric chromosomes break, and the long arms join, forming an unusual, long chromosome. |
| | A) | Robertsonian translocation |
| | B) | reciprocal translocation |
| | C) | inversion |
| | D) | duplication |
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6 | |
An individual with two normal sets of autosomes and a single X chromosome has |
| | A) | Down syndrome. |
| | B) | Patau syndrome. |
| | C) | Turner syndrome. |
| | D) | Klinefelter syndrome. |
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7 | |
This structure emanates from the centromere and contacts the spindle fibers during mitosis: |
| | A) | alpha satellite |
| | B) | subtelomere |
| | C) | euchromatin |
| | D) | kinetochore |
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8 | |
Prenatal diagnostic techniques that obtain fetal chromosomes include all but |
| | A) | amniocentesis. |
| | B) | fetal cell sorting. |
| | C) | chorionic villus sampling. |
| | D) | fluorescence in situ hybridization. |
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9 | |
When chromatids divide along the wrong plane, structures with identical arms called ____ are formed. |
| | A) | ring chromosomes |
| | B) | translocations |
| | C) | isochromosomes |
| | D) | satellites |
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10 | |
In nondisjunction, which parent leads to the sex chromosome aneuploid XYY? |
| | A) | mother |
| | B) | father |
| | C) | either parent |
| | D) | both parents |
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11 | |
____ contains protein-encoding genes. |
| | A) | heterochromatin |
| | B) | euchromatin |
| | C) | pericentric inversions |
| | D) | aneuploids |
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12 | |
Our closest relative, according to karyotypes is the |
| | A) | mouse. |
| | B) | domestic cat. |
| | C) | gorilla. |
| | D) | chimpanzee. |
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13 | |
An individual with the chromosomal description 45, X would be a |
| | A) | normal female. |
| | B) | female with Turner syndrome. |
| | C) | male with Klinefelter syndrome. |
| | D) | cannot be determined. |
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14 | |
Heterochromatic regions at the ends of chromosomes are called |
| | A) | centromeres. |
| | B) | euchromatin. |
| | C) | telomeres. |
| | D) | satellites. |
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15 | |
The photographic arrangement of chromosomes is called a (an) |
| | A) | karyotype. |
| | B) | idiogram. |
| | C) | anagram. |
| | D) | chromogram. |
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16 | |
A triploid human karyotype has how many chromosomes? |
| | A) | 23. |
| | B) | 46. |
| | C) | 69. |
| | D) | 92. |
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17 | |
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. |
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18 | |
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. |
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19 | |
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) |
| | A) | deletion. |
| | B) | duplication. |
| | C) | inversion. |
| | D) | translocation. |
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20 | |
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 |
| | B) | normal |
| | C) | translocation Down syndrome |
| | D) | all are possible outcomes |
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21 | |
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 |
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22 | |
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 |
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23 | |
How many chromosomes does a person with Edward syndrome have? |
| | A) | 45 |
| | B) | 46 |
| | C) | 47 |
| | D) | 48 |
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24 | |
All of the following aneuploids result from female nondisjunction except |
| | A) | Klinefelter syndrome. |
| | B) | triplo-X. |
| | C) | Turner syndrome. |
| | D) | Jacobs syndrome. |
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25 | |
Alagille syndrome results from a (an) |
| | A) | inversion. |
| | B) | duplication. |
| | C) | translocation. |
| | D) | isochromosome. |
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