MEDICAL GENETICS CHAPTER 20 CERTIFICATION EVALUATION TEST COMPLETE QUESTIONS AND CORRECT ANSWERS.pdf

MEDICAL GENETICS CHAPTER 20
CERTIFICATION EVALUATION TEST COMPLETE
QUESTIONS AND CORRECT ANSWERS

◉ transcription.
Answer: DNA transcribed into mRNA


◉ translation.
Answer: mRNA leaves nucleus & proteins are synthesized


◉ what is transcription and translated mediated by?.
Answer: RNA (ribonucleic acid)


◉ autosomal dominant.
Answer: a phenotype expressed when heterozygous or homozygous
for a genotype


◉ autosomal recessive.
Answer: a phenotype expressed only when homozygous for a
genotype


◉ homozygous.

,Answer: alleles are identical


◉ heterozygous.
Answer: alleles are different


◉ carrier.
Answer: individual who is heterozygous for a recessive trait


◉ x-linked.
Answer: referring to a gene located on the X chromosome


◉ y-linked.
Answer: referring to a gene located on the Y chromosome


◉ pleiotropism.
Answer: single mutant gene may have many end-organ effects


◉ locus heterogeneity.
Answer: mutations at several genetic loci may produce the same
trait
(same disease phenotype)

, ◉ with autosomal dominant diseases, ______ of the children will be
heterozygotes and express the disease..
Answer: 1/2


◉ what is an example of an autosomal dominant disease?.
Answer: marfan syndrome (70- 80% familial)


◉ fibrillin.
Answer: major component of microfibrils found in extracellular
matrix


◉ where is fibrillin particularly abundant?.
Answer: aorta, ligaments, ciliary zonules (eyes)


◉ autosomal recessive disorders.
Answer: 1/4 of the offspring with be affected
1/2 of the offspring will be unaffected heterozygous carriers


◉ what is common with autosomal recessive disorders ?.
Answer: penetrance


◉ when is the onset of autosomal recessive disorder?.