Biology

Human Genetics and Disorders

844 Questions

Human Genetics and Disorders covers the inheritance patterns, genetic mutations, and molecular basis of hereditary diseases. Topics include sex-linked traits, cancer genetics, and metabolic disorders. This section tests knowledge critical for biology exams and general science papers.

Genetic mutationsInherited disordersCancer geneticsGenetic testingMendelian inheritance

Human Genetics and Disorders Questions

Multiple choice

Which of the following syndromes is associated with Uniparental disomy for chromosome 15 in which both chromosomes are maternally derived?

  1. Prader-Willi syndrome

  2. Angelman syndrome

  3. Rett syndrome

  4. Beckwith-Wiedemann syndrome
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Having maternal uniparental disomy for chromosome 15 results in Prader-Willi syndrome. It is caused by the loss of function of genes in a particular region of chromosome 15 & affects many parts of the body.

Multiple choice

Which of the following does not characterise the tumor suppressor genes?

  1. Transmitted as dominant traits in families

  2. May be associated with loss of heterozygosity in tumors.

  3. Act dominantly in tumor cells.

  4. Associated with two-hit model of carcinogenesis.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Tumor suppressor gene mutations are transmitted in a dominant manner in families, but act recessively in tumor cells,which is why two hits are required in the tumor.

Multiple choice

Which type of mutation would not be expected to be detected in a molecular diagnostic test that is based on sequencing each exon of a gene in genomic DNA from a male suspected of having an X-linked disorder?

  1. Missense mutation

  2. Nonsense mutation

  3. Deletion of an exon

  4. Inversion of part of the gene
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Yes, the inversion of part of gene cannot be detected . As it would not cause the exons to be absent or missing, and the sequencing reaction would not reveal that the exons are no longer arranged in the proper order on genomic DNA.

 

Multiple choice

What are Amsterdam criteria used to assess?

  1. Risk of hereditary nonpolyposis colon cancer.

  2. Risk of familial adenomatosis polyposis.

  3. Risk of hereditary breast and ovarian cancer.

  4. Risk of Cowden syndrome.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, it is the correct answer. The Amsterdam criteria are used to assess risk of HNPCC to guide identification of individuals for whom genetic testing may be helpful.

Multiple choice

Angelman syndrome is a severe form of mental retardation which depends upon the gender of the parent from whom they are inherited. This unusual kind of inheritance pattern is known as

  1. modifying gene

  2. genome imprinting

  3. incomplete penetrant

  4. intermediate expression
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When genes have a different effect depending on the gender of the parent from whom they are inherited, it is referred to as genome imprinting. Diabetes, psoriasis, and Prader-Willi syndrome are other examples of this phenomenon.

Multiple choice

Pick out the true statement regarding the karyotype analysis.

  1. It is frequently done on the cells of foetus because it cannot detect the most genetic disorders.

  2. It is now an important medical tool used in forecasting the likelihood that the foetus will be normal.

  3. It is not used, now a days, because human pregnancy has only a small risk of birth defects.

  4. It is the number and appearance of chromosomes in the nucleus of a prokaryotic cell.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When the family history or age of the mother indicates a high risk of gross chromosomal abnormalities, embryonic or fetal tissue samples are often collected and cultured so that a karyotype of the chromosomes can be analyzed.