Biology

Human Genetics and Disorders

882 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

Colour blindness is a/an

  1. congenital disease

  2. acquired disease

  3. contagious disease

  4. cancer

  5. allergy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, it is correct. This disease is caused due to defective inheritance.

Multiple choice

Adenosine deaminase(ADA) deficiency is a syndrome that is seen in children especially below 12 years. Which of the following can be considered as a permanent cure to this disorder?

  1. Bone marrow transplantation

  2. Enzyme replacement therapy

  3. Infusion of genetically engineered lymphocytes

  4. Introduction of gene isolated from bone marrow cells producing ADA into cells at early embryonic stages
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Adenosine deaminase deficiency also known as ADA deficiency or ADA-SCID  is an autosomal recessive metabolic disorder that causes immunodeficiency. Introduction of gene isolated from bone marrow cells producing ADA into cells at early embryonic stages can be considered as a permanent cure to this disorder.

Multiple choice

Which syndrome is associated with chromosome 13?

  1. Edward's syndrome

  2. Patau syndrome

  3. Wolf-Hirschhorn syndrome

  4. DiGeorge syndrome
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Patau syndrome is a chromosomal abnormality in which a patient has an additional chromosome 13 due to a nondisjunction of chromosomes during meiosis.

Multiple choice

Which of the following statements about the genetic disorders is correct?

  1. Mongolism is more common in children born to younger women.

  2. Prenatal genetic disorders can be found out by amniocentesis.

  3. Non-disjunction of chromosomes during oogenesis is more frequent in younger women.

  4. In phenylketonuria, the infant suffers from acute damage of the brain and the spinal cord.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Prenatal genetic disorders can be found out by amniocentesis which involves the prenatal diagnosis of chromosomal abnormalities and foetal infections.

Multiple choice

Phenylketonuria is a genetic disorder of

  1. trisomic condition

  2. monosomic dominant gene

  3. autosomal dominant gene

  4. autosomal recessive gene

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

Phenylketonuria (PKU) is a caused due to mutation in gene on chromosome 12.Gene codes for phenylalanine hydroxylase that breaks phenylalanine into other products.

Multiple choice

A defective gene leads to major defect in the offspring. This is a/an _________ factor affecting health.

  1. intrinsic

  2. extrinsic

  3. community

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

A defective gene that leads to a defect is a factor which is present inside the body cells of an organism. Hence, it is an internal factor. Extrinsic factors are those which are outside of the body and they include causative agents, diet, community, social system, etc.

Multiple choice

A multifactorial trait occurs more often in females than males. A couple have an affected son. Which of the following is true regarding their risk of recurrence?

  1. Recurrence is higher if they had an affected daughter, and is most likely for a future son.

  2. Recurrence is higher if they had an affected daughter, and is most likely for a future daughter.

  3. Recurrence is lower if they had an affected daughter, and is most likely for a future son.

  4. Recurrence is lower if they had an affected daughter, and is most likely for a future daughter.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Since females are more often affected, having an affected son implies greater liability towards the trait. This increases their risk for future offspring. The trait will always be more common in females than males.

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.