Open Question
A boy with Down syndrome (trisomy 21) has 46 chromosomes. His parents and his two older sisters have a normal phenotype, but each has 45 chromosomes.
How many chromosomes do you expect to see in karyotypes of the parents?
6. Chromosomal Variation
Chromosomal Rearrangements: Translocations
Back6. Chromosomal Variation
Chromosomal Rearrangements: Translocations
- Open Question
A boy with Down syndrome (trisomy 21) has 46 chromosomes. His parents and his two older sisters have a normal phenotype, but each has 45 chromosomes.
Explain how this is possible. - Open QuestionA woman who sought genetic counseling is found to be heterozygous for a chromosomal rearrangement between the second and third chromosomes. Her chromosomes, compared to those in a normal karyotype, are diagrammed to the right.This woman is phenotypically normal. Does this surprise you? Why or why not? Under what circumstances might you expect a phenotypic effect of such a rearrangement?
- Open QuestionA woman who sought genetic counseling is found to be heterozygous for a chromosomal rearrangement between the second and third chromosomes. Her chromosomes, compared to those in a normal karyotype, are diagrammed to the right.What kind of chromosomal aberration is shown?