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 bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

A child has blood group B. Mother has blood group A. The blood group of the father would be

  1. O

  2. O or A

  3. B or AB

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

Child is B (genotype BO or BB). Mother is A (genotype AO or AA). To have a B child, the father must provide a B allele. Thus, the father could be B (BO or BB) or AB.

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

The genotype of B-group father of an O-group child is

  1. $I^O I^O$
  2. $I^B I^B$
  3. $I^A I^B$
  4. $I^O I^B$.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A child with blood group O has genotype OO. If the father is blood group B, he must be heterozygous (genotype BO, represented as I^O I^B) to pass on the O allele to the child.

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

Husband and wife should know their Rh factors because the situation can be serious due to biological incompatibility in one of the following cases

  1. $Rh^+$ husband and $Rh^+$ wife
  2. $Rh^-$ husband and $Rh^-$ wife
  3. $Rh^-$ husband and $Rh^+$ wife
  4. $Rh^+$ husband and $Rh^-$ wife.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Rh incompatibility occurs when an Rh-negative mother carries an Rh-positive fetus. This can lead to the mother developing antibodies against the Rh antigen, which may affect subsequent pregnancies.

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

A man with blood group A marries AB blood group woman. Which type of progeny indicate that the man is not homozygous?

  1. AB

  2. B

  3. A

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

A man with blood group A can have genotype AA or AO. If he is AO and marries an AB woman (genotypes A and B), they can produce a child with blood group B (genotype BO). If he were AA, he could only produce A or AB children.

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

Parents with blood groups O and AB cannot have AB child as

  1. Gene for O is dominant over gene for B

  2. Gene for O is dominant over gene for A

  3. Genes for A and B are absent in one of the parents

  4. Gene for A or B is absent in one of the parents.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A parent with blood group O has the genotype OO. A parent with blood group AB has the genotype AB. The child must inherit an O from the first parent, making it impossible for the child to have the genotype AB.

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

A boy has the blood group 0. What is true of the inheritance of this blood group in his case?

  1. His mother should be with AB blood group

  2. Both his parents could be heterozygous A group

  3. His father could be homozygous B group

  4. His mother could be homozygous A group
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If the boy has blood group o, both his parents could probably be heterozygous A group, $I^AI^O$, in both the parents.

So, the correct option is 'Both his parents could be heterozygous A group'.

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

A woman of blood group O' presented a baby of blood groupO' which she claimed as her child. She brought a suit against a man of 'AB' group as the father of the child. 

Which statement is correct as per your judgement

  1. The father and mother claimed are the true persons

  2. Father is true and mother is not the true person

  3. Both the parentage claims are false

  4. Mother is the true person and father claimed is not true
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A mother with blood group O (ii) can only have a child with blood group O if the father provides an i allele. A man with blood group AB (IAIB) does not possess the i allele and therefore cannot be the biological father of an O child.

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

Which disease occurs due to Rh incompatibility?

  1. Sickle cell anaemia

  2. Thalassemia

  3. Erythroblastosis foetalis

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

. If an Rh-positive man marries an Rh-negative woman, then the first foetus (and foetuses thereafter) will be Rh-positive. In this case, the Rh-positive antigen from the foetus will enter into the bloodstream of the mother and there will be the formation of anti-Rh antibodies in mother’s body. During her second pregnancy, these antibodies will attach the red blood cells of the Rh-positive foetus and coagulate the blood, resulting in severe complications. These complications arising due to Rh incompatibility are called erythroblastosis foetalis.

So, the correct answer is 'Erythroblastosis foetalis'.

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

Which disorder is due to gene incompatibility?

  1. Erythroblastosis fetalis

  2. Jaundice

  3. Hemolytic disease of new born

  4. Both A and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Erythroblastosis fetalis is a hemolytic anemia in the fetus caused by the transplacental transmission of maternal antibodies to the fetal RBCs. In this alloimmune condition that develops in the fetus, the IgG molecules produced by the mother pass through the placenta and so is because of incompatibility.
Jaundice is caused because of the excess of bilirubin in the blood.
Therefore, the correct answer is option D.

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

Sickle cell anaemia is due to

  1. Deficiency of vitamin B.

  2. Deficiency of iron in the blood.

  3. A genetically determined defect of haemoglobin synthesis.

  4. Increase in the number of leucocytes in the blood.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sickle cell anemia is the serious disorder in which the body makes sickle-shaped red blood cells. RBCs contain hemoglobin which carries oxygen from lungs to rest of the body. Sickle cells contain abnormal hemoglobin called sickle hemoglobin.
Thus, the correct answer is option (C), 'A genetically determined defect of haemoglobin synthesis'.

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

The disease as a result of prolonged clotting time is due to the lack of plasma thromboplastin component (PTC) necessary to the formation of thromboplastin, is

  1. Christmas disease

  2. Hypoprothrombinemia

  3. Haemophilia

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

The Christmas disease is nothing but the Haemophilia B. It is a blood clotting disorder caused by a mutation of the factor IX gene, leading to a deficiency of factor IX . It is called as Christmas disease, as it is named after Stephen Christmas, the first patient described with this disease.
Therefore, the correct answer is option A.

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

Hereditary disease condition in which the blood fails to coagulate

  1. Sickle cell anaemia

  2. Leukemia

  3. Haemophilia

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

Haemophilia is a group of hereditary disease, that impair the body's ability to control blood clotting or coagulation.
Thus, the correct answer is option (C), 'Haemophilia'.