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

In a family, having a history of genetic disorders, knowing the sex of a foetus can be important because

  1. sons will be more prone to autosomal defects

  2. daughters will be more prone to autosomal defects

  3. both son & daughter will be equally affected

  4. There will be more chances that sons will bear X-linked traits expressed in their phenotype.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

There is a far greater probability of males expressing recessive alleles in their phenotypes if they are carried on X chromosomes. For females to have such traits, they would have to inherit the recessive allele for them on both of their X chromosomes.

Multiple choice

A female is suffering from unusually short height (average 4'7), webbed neck, & lacks all feminine secondary sexual characteristics. This chromosomal abnormality is caused by

  1. Triple-X syndrome

  2. Turner's syndrome

  3. XYY syndrome

  4. Klinefelter's syndrome
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Women with Turner syndrome are essentially postmenopausal from early childhood and are sterile because their ovaries do not develop normally and they do not ovulate.

Multiple choice

Which among the following chromosomal abnormalities causes male to have feminine body contours with bigger breasts; small penis and prostate gland with relatively little body hair and impotency?

  1. Klinefelter's syndrome

  2. XYY syndrome

  3. Richard Speck Syndrome

  4. Achard syndrome
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The feminising effects of Klinefelter syndrome can be diminished if boys are treated regularly with testosterone injections from the age of puberty. As a result of this treatment, most become sufficiently ordinary in appearance to live in society without notice.

Multiple choice

A recessive allele p is responsible for a condition called hypertonia. In a couple, male has this condition. One of their four children also has this condition. Suggest the possible genotypes of the man and woman.

  1. Father is Pp and mother is PP.

  2. Father is pp and mother is PP.

  3. Both parents are pp.

  4. Father is pp and mother is Pp
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the only option that fits the criteria in the question. Since father is hypertonic so he must be pp & mother is carrier so she must be Pp.

Multiple choice

The severe medical problem associated with the Rh blood group is

  1. transfusion incompatibility

  2. chronic anemia for Rh negative persons

  3. Chronic anemia for Rh positive persons

  4. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The most life threatening problem is the result of Rh blood type incompatibility between a mother and her developing fetus.

Multiple choice

The genetic disorder sickle-cell anemia signifies

  1. mutation

  2. pleiotropy

  3. epistasis

  4. heterozygous dominance
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sickle cell is an example of a mutation that is beneficial when maintained in heterozygotes. When you are homozygous for the trait you get sickle cell anemia. When a person is heterozygous for the sickle cell gene they have some added protection from malaria.

Multiple choice

Why are men more prone to colour blindness than women?

  1. The colour blindness is an X-linked dominant trait.

  2. The gene for colour blindness is located on the Y chromosome.

  3. Women lacks Y chromosomes

  4. The colour blindness is an X-linked recessive trait.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Since colour blindness is a recessive trait, men, who have only 1 copy of the X chromosome, will always be color blind if they inherit the defective gene. Women must inherit two defective copies in order to be color blind.

Multiple choice

Wilson disease is a rare autosomal recessive inherited disorder of copper metabolism. Among the following ammonium salts which one is used in the treatment of Wilson's disease?

  1. Ammonium heptamolybdate

  2. Ammonium hexachloroplatinate

  3. Ammonium hexafluoroaluminate

  4. Ammonium tetrathiomolybdate
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Ammonium tetrathiomolybdate [NH4]2MoS4 is bright red ammonium salt, an important reagent in the chemistry of molybdenum and has been used as a building block in bioinorganic chemistry. It was first used therapeutically in the treatment of copper toxicosis in animals. It is also used in the treatment of Wilson's disease.

Multiple choice

Mutation in the RET oncogene is associated with increased risk of

  1. endometrial cancer

  2. PNET cancer

  3. prostate cancer

  4. adenocarcinoma

  5. medullary thyroid cancer
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Endometrial cancer begins in the layer of cells that form the lining (endometrium) of the uterus. The causes of endometrial cancer are still unknown.

Multiple choice

Which of the following is most commonly seen in African children with Burkitt's lymphoma?

  1. Chromosome 8q24 to Chromosome 2p12 translocation

  2. Chromosome 8q24 to Chromosome 14q32 translocation

  3. Deletion of the c-myc gene

  4. T-cell neoplasia

  5. Absence of EBV

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The c-myc gene (chromosome 8q24) involved in the entry of cells from resting G0 into the cell cycle is translocated to the mu heavy chain gene (chromosome 14q32) in most cases of Burkitt's lymphoma studied.