WorksheetsMedical genetics
Total questions: 10
Worksheet time: 4mins
Prospective genetic counseling occurs in which of the following situations?
When a couple is told their fetus will be born with a genetic disease.
After an individual develops a genetic disease.
When a couple is identified as at risk for developing a genetic disease.
After a couple has a child with a birth defect or genetic disease.
The phenotype is the observable characteristics of an organism based on the genotype, which is the genetic composition of an organism. Which one of the following individuals is expected to display a normal phenotype?
A man with deletion of a band on chromosome 4.
A woman with 46 chromosomes, with a Robertsonian translocation between chromosomes 14 and 21.
A woman with 45 chromosomes, with a Robertsonian translocation between chromosomes 14 and 21.
A woman with karyotype 47, XX,+18.
Which of the following statements describes Klinefelter's syndrome accurately?
It is characterised by a 47,XXY karyotype with hypogonadism after puberty.
It is seen at a higher frequency in males in prison than in the general population.
It is characterised by ambiguous genitalia at birth.
It occurs in a phenotypic female with 46,XY karyotype.
Characteristics of women with Turner's syndrome include which of the following?
They have a higher than normal risk of developing breast cancer.
They usually undergo normal pubertal changes.
They almost always display short stature.
They are mentally retarded.
What is the Philadelphia chromosome?
(a)
Retinoblastoma, a rapidly developing eye cancer which originates in the cells of the retina, is caused by which of the following?
(a)
The biochemical causes of both myoclonic epilepsy with ragged red fibers (MERRF) and mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) are most often which of the following?
Defects in a single nuclear gene/protein, resulting in abnormal mitochondrial function.
Mutations in a mitochondrial ribosomal RNA gene, resulting in defects of multiple mitochondrial protein complexes.
Deletions of mitochondrial DNA, resulting in defects in multiple mitochondrial protein complex.
Mutations in a mitochondrial transfer RNA gene, resulting in defects in multiple mitochondrial protein complexes.
Which answer describes triploidy correctly?
It is a conception with one extra chromosome.
It is a conception with one extra haploid set of chromosomes.
It is usually not diagnosed in an infant until after the first year of life.
It is the most common chromosomal abnormality seen in spontaneous abortions.
Chorionic villus sampling (CVS) is a technique which is essentially a biopsy of the placenta. CVS is indicated in which of the following situations?
The patient's brother has Down's syndrome.
The couple had a previous child with spina bifida.
The father is a carrier of a 14;21 translocation.
Fetal omphalocele was detected by ultrasound at 20 weeks gestation.
X chromosome inactivation is a mechanism for which of the following?
Distinguishing between males and females.
Elimination of deleterious genes from the X chromosome.
Maintaining polymorphisms in the population.
Gene dosage compensation in mammals.
