1. Mutations near the carbosyl terminal of the procollagen al molecule (enooded by COL/AL) cause mere severe symptoms than those in the amino teminni, This is an example of A. dominant negative mutation. B. locus heterogeneity. D. allelic heterogeneity. E. haploinsufficiency. C. haplosufficiency. 2. Which of the following could produce X Y females and XX males? A. Deletion of the SR Y gene. B. Point mutation in the SRY gene. C. Insertion of the SR Y gene to the different region of Y chromosome in the father. D. Deletion of the Y ehromosome. E. Trunsloeation of the SRY gene to the X ehromosome during meiosis in the fither. 3. In Siekle Cell Disease genotypes, while AA and A S are both phenotypically healthy. S 5 suffers from the disense. However, both A S and SS genotypes also produce sickle cells (sickleskaped red blood cells) altiough A S also produces normal red blood cells. Which of the following best describes the relationship between A and S alleles? A. A is dominant to S in sickle cell production. B. A is dominant to S in sickle cell disease, but A and S are codominant in sickle cell production. C. A is dominant to S in siekle cell discase and in sickle cell production. D. A is dominant to S in sickle cell disense, but A is incompletely dominant to S in siekle cell production. E. A is dominant to S in sicklo cell disense, but A is dominant to S in sickle cell production. 4. In 8-Thalasseinia, nonsense or frameshift mutations can teminate translation in exon 3 .of the p-giobin gene, The resuiting mRNA produces unstable -globin chains. This destabilizes the normal p-globin chains produeed by the normal allele in heterozygotes. Consequently, heteroxygotes become affected. This is in evample of A. dominant mutatibn: B. haploinsufficiency. C. haplosufficiency. D. dominant netative inutation. E. missense mutation. 3. Reet Syndrome is X-linked dominant. Affected females tend to show variable expression of symptoms Which also tend to be milder. This is because A. of X ehromosome inactivation: cells with the normal recessive allele inactivated will express the dominant disease allole. B. of X chromosome inactivation: cells with the normal dominant allele inactivated will express the recestive disease allele: C. the disease is incomplete dominant in these females. D. these females just have an increased penetrance. E. these females suffer from Tumer syndrome ( 45 , X ) , carrying only one X chromosome. 6. A phenotypically nomal woman has had two children with Down syndrome. Which of the following scenarios would be most likely the cause? A, She is a germ-line mosaic for trisomy 13 . B. She carries a Robertsonian transiocation of chromosome 13 to chromosome 14. C. She carrics a Robertsonian translocation of chromosome 22 to chromosome 14. D. She has had both children in her late 40 s. E. She carries a Robertsonian translocation of chromosome 13 to chromosome 15. .

1. 1. Mutations near the carbosyl terminal of the procollagen al molecule (enooded by COL/AL)
cause mere severe symptoms than those in the amino teminni, This is an example of A. dominant
negative mutation. B. locus heterogeneity. D. allelic heterogeneity. E. haploinsufficiency. C.
haplosufficiency. 2. Which of the following could produce X Y females and XX males? A.
Deletion of the SR Y gene. B. Point mutation in the SRY gene. C. Insertion of the SR Y gene to
the different region of Y chromosome in the father. D. Deletion of the Y ehromosome. E.
Trunsloeation of the SRY gene to the X ehromosome during meiosis in the fither. 3. In Siekle
Cell Disease genotypes, while AA and A S are both phenotypically healthy. S 5 suffers from the
disense. However, both A S and SS genotypes also produce sickle cells (sickleskaped red blood
cells) altiough A S also produces normal red blood cells. Which of the following best describes
the relationship between A and S alleles? A. A is dominant to S in sickle cell production. B. A is
dominant to S in sickle cell disease, but A and S are codominant in sickle cell production. C. A is
dominant to S in siekle cell discase and in sickle cell production. D. A is dominant to S in sickle
cell disense, but A is incompletely dominant to S in siekle cell production. E. A is dominant to S
in sicklo cell disense, but A is dominant to S in sickle cell production. 4. In 8-Thalasseinia,
nonsense or frameshift mutations can teminate translation in exon 3 .of the p-giobin gene, The
resuiting mRNA produces unstable -globin chains. This destabilizes the normal p-globin chains
produeed by the normal allele in heterozygotes. Consequently, heteroxygotes become affected.
This is in evample of A. dominant mutatibn: B. haploinsufficiency. C. haplosufficiency. D.
dominant netative inutation. E. missense mutation. 3. Reet Syndrome is X-linked dominant.
Affected females tend to show variable expression of symptoms Which also tend to be milder.
This is because A. of X ehromosome inactivation: cells with the normal recessive allele
inactivated will express the dominant disease allole. B. of X chromosome inactivation: cells with
the normal dominant allele inactivated will express the recestive disease allele: C. the disease is
incomplete dominant in these females. D. these females just have an increased penetrance. E.
these females suffer from Tumer syndrome ( 45 , X ) , carrying only one X chromosome. 6. A
phenotypically nomal woman has had two children with Down syndrome. Which of the
following scenarios would be most likely the cause? A, She is a germ-line mosaic for trisomy 13
. B. She carries a Robertsonian transiocation of chromosome 13 to chromosome 14. C. She
carrics a Robertsonian translocation of chromosome 22 to chromosome 14. D. She has had both
children in her late 40 s. E. She carries a Robertsonian translocation of chromosome 13 to
chromosome 15.