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 sexually transmitted diseases stds and infertility reproductive health reproduction biology

Which one is a sex-related disease?

  1. Christmas disease

  2. Klinefelter's syndrome

  3. Phenylketonuria

  4. Albinism
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
In haemophilia, the blood does not clot as it should. Haemophilia is normally an inherited disorder. It happens because of a defect in one of the clotting factor genes on the X chromosome. Haemophilia tends to occur in males since the gene can be passed from mother to son. Males typically lack a second X chromosome so they are unable to make up for the defective gene. Most females have XX sex chromosomes while most males have XY sex chromosomes.
Haemophilia B, also known as "Christmas disease," occurs when a person lacks clotting factor IX.
So, the correct answer is 'Christmas disease'.
Multiple choice sexually transmitted diseases stds and infertility reproductive health reproduction biology

Assertion:  Males suffer from sex-linked disorders more often than females.

Reason: Sex-linked traits are mostly governed by recessive genes.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion

  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion

  3. If the assertion is true but the reason is false

  4. If both the assertion and reason are false

  5. If the assertion is false but reason is true
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Males have only one X chromosome, so any recessive sex-linked gene on that chromosome will be expressed. Females have two X chromosomes, so they must inherit two copies of the recessive gene to express the trait, making it much rarer for them.

Multiple choice zoology biotechnology and its applications stem cell stem cells and applications stem cells organ donation and body donation blood and organ donation

Which of the following is considered as a complication of stem cell transplantation?

  1. Graft-versus-host disease

  2. Down syndrome

  3. Huntington's disease

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The stem cell transplantation is the method which can be used for the treatment of many disorders like cancer, genetic defects, etc. The main complication of this method is graft rejection by the host. The graft may contain antigens which act as a foreign body in the host. The antibodies are produced against this organ which results in the rejection and destruction of the organ in the host. 

Thus, the correct answer is option A. 

Multiple choice zoology genetics of the future gene therapy application of biology in therapy and vaccine gene cloning

SCID is caused by defective gene coding for enzyme ______________.

  1. Adenosine deaminase

  2. Adenosine transaminase

  3. Adenosine transferase

  4. Guanosine transaminaseGuanosine deaminase
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Adenosine deaminase deficiency SCID, commonly called ADA SCID, is a very rare genetic disorder. It is caused by a mutation in the gene that encodes a protein called adenosine deaminase (ADA). 

Multiple choice zoology genetics of the future gene therapy application of biology in therapy and vaccine gene cloning

Enzyme adenosine deaminase is deficient in .......... genetic disorder.

  1. Alzheimers disease

  2. Muscular dystrophy

  3. SCID

  4. Colour blindness
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The correct option is C


Severe combined immunodeficiency (SCID) is an X-limbed inherited disorder of the immune system, that occurs almost exclusively in males. Boys with x-linked SCID are prone to recurrent and persistent infections because they 
lack the necessary immune cells to fight off certain bacteria, viruses, etc, It is 
caused by a disorder of or by a deficiency of the adenosine deaminase which is very necessary for lymphocyte development.

Multiple choice zoology genetics of the future gene therapy application of biology in therapy and vaccine gene cloning

First clinical application of gene therapy was used in 1992 over a four year old girl for

  1. Adenosine deficiency

  2. Adenine deficiency

  3. Growth deficiency

  4. Adenosine deaminase deficiency
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The first successful gene therapy trial in 1990 (often cited as 1992 in some texts) was performed on Ashanthi DeSilva for Adenosine Deaminase (ADA) deficiency.

Multiple choice zoology genetics of the future gene therapy application of biology in therapy and vaccine gene cloning

The genetic defect adenosine deaminase (ADA) deficiency may be cured permanently by

  1. Introducing bone marrow cells producing (ADA) into cells at an early embryonic stage.

  2. Administrating adenosine deaminase activators.

  3. Periodic infusion of genetically engineered lymphocytes having functional ADA cDNA.

  4. Enzyme replacement therapy.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Permanent cure for ADA deficiency involves introducing functional ADA genes into bone marrow stem cells at an early stage, allowing the body to produce its own functional enzyme.

Multiple choice zoology genetics of the future gene therapy application of biology in therapy and vaccine gene cloning

Which of the following statements is incorrect about gene therapy in ADA deficiency?

  1. Lymphocytes from patient's blood are taken out and cultured.

  2. A functional ADA cDNA is introduced into these lymphocytes.

  3. Lymphocytes are then introduced in the body of patient.

  4. Patient does not require periodic infusion of genetically engineered lymphocytes.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
As a first step towards gene therapy, lymphocytes from the blood of the patient are grown in a culture outside the body. A functional ADA-cNDA  (using a retroviral vector) is then introduced into these lymphocytes, which are subsequently returned to the body of the patient. However, as these cells are not immortal, the patient requires periodic infusion of such genetically engineered lymphocytes.
So, the correct answer is 'Patient does not require periodic infusion of genetically engineered lymphocytes'.
Multiple choice zoology genetics of the future gene therapy application of biology in therapy and vaccine gene cloning

Adenosine deaminase deficiency can be permanently cured by which of the following methods?

  1. Bone marrow transplantation

  2. Enzymes replacement therapy

  3. Gene therapy at early embryonic stages

  4. All of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Adenosine deaminase (ADA) deficiency can be treated by bone marrow transplantation, or by enzyme replacement therapy, in which functional ADA is given to the patient by injection. But permanent treatment can be done by introduction of gene isolated from bone marrow cells, which produces ADA, into the cells of the patient at early embryonic stage.

Multiple choice zoology genetics of the future gene therapy application of biology in therapy and vaccine gene cloning

Diseases that are caused by the malfunction of a phototropic gene are:

  1. Cured by dietary restrictions

  2. Reversible by gene therapy

  3. Called as syndromes

  4. Extremely rare
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Phototropism is the growth of an organism which responds to a light stimulus. It is most often observed in plants, but can also occur in other organisms such as fungi. The cells on the plant that are farthest from the light have a chemical called auxin that reacts when phototropism occurs. Gene therapy is an experimental technique that uses genes to treat or prevent disease. In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patient's cells instead of using drugs or surgery. 
So the correct option is 'Reversible by gene therapy'.
Multiple choice zoology genetics of the future gene therapy application of biology in therapy and vaccine gene cloning

What is the permanent cure of adenosine deaminase (ADA) deficiency in children?

  1. Bone marrow transplantation

  2. Enzyme replacement therapy in which functional ADA is given to patient by injection

  3. Infusion of genetically engineered lymphocytes (in which functional ADA-cDNA is introduced) into the patient's blood

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

Adenosine deaminase (ADA) deficiency can be treated by bone marrow transplantation, or by enzyme replacement therapy, in which functional ADA is given to the patient by injection. But permanent treatment can be done by introduction of gene isolated from bone marrow cells, which produces ADA, into the cells of the patient at early embryonic stage.

Multiple choice zoology genetics of the future gene therapy application of biology in therapy and vaccine gene cloning

Which kind of therapy was given in $1990$ to a four-year-old girl with Adenosine Deaminase(ADA) deficiency?

  1. Gene therapy

  2. Chemotherapy

  3. Immunotherapy

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

First successful gene transfer in human was performed by F.Anderson. Ashi Disilva a 4-year girl was treated by replacing ADA gene in lymphocytes.

The girl was suffering from Severe Combined Immunodeficiency (SCID). Gene therapy was used for the treatment of ADA deficiency.
So, the correct option is 'Gene therapy'.

Multiple choice zoology applications of biotechnology gene therapy application of biology in therapy and vaccine gene cloning

Immune deficiency disorder, which occur due to mutation in gene, involved in maturation of T and B lymphocytes is

  1. IDDM

  2. Hashimoto disease

  3. SCID

  4. Pernicious anemia
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • Insulin-Dependent Diabetes Mellitus or IDDM is an immune deficiency disorder. It occurs due to a mutation in a gene involved in insulin-producing β cells in the pancreas. 
  • Hashimoto's disease is an autoimmune disorder that results in hypothyroidism. It results in defects in the maturation of T lymphocytes. 
  • Severe combined immunodeficiency (SCID) is an immunodeficiency syndrome. It occurs due to a mutation in the gene involved in the maturation of T and B lymphocytes. 
  • Pernicious anemia is also called as vitamin B$ _{12}$ deficiency syndrome. It results due to a lack of intrinsic factor. 
Thus, the correct answer is 'Hashimoto disease and SCID.'

Multiple choice biology excretion to maintain homeostasis kidney dialysis kidney disorders disorders of kidney

Black urine disease is due to

  1. Absence of alkapton oxidase

  2. Absence of homogentisic acid

  3. Metabolism of phenylalanine

  4. Metabolism of tyrosine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Black urine disease, or alkaptonuria, is caused by a deficiency of the enzyme homogentisate 1,2-dioxygenase (alkapton oxidase). This deficiency leads to the accumulation of homogentisic acid, which turns black upon oxidation in urine.