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 inborn errors of metabolism haemophilia and colour blindness non infectious diseases keeping diseases away

If both parents are bald and their first female child is normal, then the chances of baldness in their second male child is?

  1. $50$%
  2. $100$%
  3. $25$%
  4. $0$%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Male pattern baldness is a sex-influenced trait. In males, it acts as a dominant trait, while in females, it acts as a recessive trait. If both parents are bald, the male child has a 100% chance of inheriting the allele and expressing the phenotype.

Multiple choice bio-chemistry digestive system of human absorption mechanism absorption digestion

Gaucher's disease is concerned with which of the following?

  1. Abnormal fat metabolism

  2. Abnormal protein metabolism

  3. Abnormal carbohydrate metabolism

  4. Abnormal vitamin metabolism
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Gaucher's disease is an autosomal recessive inherited disorder in which glucocerebroside is not degraded and get a deposit in organs like spleen and bone marrow because the enzyme glucocerebrosidase is not able to break the lipid does not form this enzyme.
  • Liver and spleen enlargement (hepatosplenomegaly).
  • Reduction in RBCs number(anaemia).
  • Easy bruising caused, in part, by a low level of platelets (thrombocytopenia).
  • Bone disease (bone pain and fractures).
  • So the correct option is 'Abnormal fat metabolism'.
Multiple choice zoology evolution evidences for evolution - taxonomy, molecular biology and cytology evidences of evolution evidences of biological evolution

In evolutionary terms, we are more related to

  1. Skull of baby chimpanzee

  2. Adult chrmpanzee

  3. Gorilla

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

Bone structure and shape of baby chimp and infant baby skulls are very similar, with the classic huge head and tiny cute face we seem programmed to love. In adolescent chimpanzee and an adult human we can see the jaw start to lengthen in both and their overall similarity. The adult chimpanzee, who has a significantly larger and more powerful bite than any adult human. So, humans and chimpanzees appear to have very similar development in terms of bone structure as they grow up, except that humans just seem to stop at a certain point. There are a multitude of theories as to why this happens, but they all seem to follow the pattern of certain behaviours being selected for which affect the balance of hormones in the body that control the development of adult features. This is called neoteny. So, we can say in evolutionary terms, we are more related to skull of baby chimpanzee than apes, gorillas and adult chimp. Thus, option A is correct and other options are wrong.

Multiple choice pleiotropy genetics zoology

A pleiotropic gene in humans is

  1. Marfan's syndrome

  2. Colour blindness

  3. Eye colour

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

Mutations in the human gene for fibrillin-1 (FBN1) in the Marfan syndrome and related disorders. Mutations in FBN1 produce Marfan syndrome, a pleiotropic autosomal dominant connective tissue disorder with prominent manifestations in the skeleton, eye and cardiovascular system.

So, the correct information is 'Marfan's syndrome.'

Multiple choice pleiotropy genetics zoology

The gene disorder phenyl ketonuria is an example for ___________.

  1. Polygenic inheritance

  2. Pleiotropy

  3. Multiple allelism

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

Phenylketonuria is a recessive autosomal disorder related to phenylalanine metabolism. It is controlled by a single gene having  multiple phenotypes. So it is a pleiotrophy. This disorder is due to the absence of a liver enzyme phenylalanine hydroxylase. Due to the lack of this enzyme, phenylalanine follows another pathway and gets converted into phenyl pyruvic acid. This phenyl pyruvic acid upon accumulation in joints causes arthritis. If it hits the brain, it causes mental  retardation known as phenyl pyruvic idiocy.

So, the correct option is ‘Pleiotrophy’

Multiple choice pleiotropy genetics zoology

In Drosophila gene for white eye colour is also responsible for depigmentation of body parts. It is an example of

  1. Oncogene

  2. Epistatic gene

  3. Hypostatic gene

  4. Pleiotropic gene

  5. Sex-linked
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The ability of a gene to have a multiple phenotypic effects is known as pleiotrophy and the gene is called Pleiotropic gene and the inheritance is called Pleiotropic inheritance. In Drosophila, a gene is responsible in controlling the colour of the eye and depigmentation of body parts. It is a pleiotropic gene.

So, the correct option is ‘Pleiotropic gene’.

Multiple choice pleiotropy genetics zoology

Which of the following disorders is not caused by pleiotropic alleles _______________.

  1. Sickle cell anemia

  2. Cystic fibrosis

  3. Phenylketonuria

  4. Erythroblastosis foetalis.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A.Sickel cell anaemia – Pleiotropic alleles

B.Cystic fibrosis – Pleiotropic alleles

C.Phenylketonuria – it is autosomal recessive disorder.

D.Erythroblastosis foetalis – It is also called hemolytic disease of the newborn, type of anemia in which the red blood cells (erythrocytes) of a foetus are destroyed in a maternal immune reaction resulting from a blood group incompatibility between the foetus and its mother.

So, the correct option is ‘Erythroblastosis foetalis’.

Multiple choice pleiotropy genetics zoology

Pleiotropic effect is found in

  1. Human skin colour

  2. Night blindness

  3. Haemophilia

  4. Sickle cell anaemia
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The ability of a gene to have a multiple phenotypic effects is known as pleiotrophy and the gene is called Pleiotropic gene and the inheritance is called Pleiotropic inheritance.

eg:Sickel cell anaemia

So, the correct option is ‘sickle cell anaemia’.

Multiple choice zoology important and common human diseases diseases caused by changes in lifestyle diseases and toxic substance non-infectious diseases

Alteration in which genes leads to cancer

  1. Proto-oncogenes

  2. Tumor suppressor gene

  3. Tumor virus gene

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Genes are found in the DNA of every cell of the human body. The functions of the cell, its growth pattern, divisions and life are all determined and control by the genes. Cancers in the human body are the result of mutations or changes in one or more genes in a cell leading to an abnormal protein or no protein at all. An abnormal protein in the cells causes them  to multiply uncontrollably and become cancerous. Any alteration in the tumour suppressor gene may result in cancer. 

The region of the viral genome (DNA in DNA tumour viruses or RNA in RNA-tumour viruses) that can cause a tumour is called an oncogene. These mutations are generally acquired mutations. However, alterations or mutations of cell proliferation genes or oncogenes lead to cancer.
So, the correct answer is option D. 

Multiple choice zoology important and common human diseases allergy and autoimmune diseases allergy non infectious diseases

Which of the following term is used as inherited tendency to develop allergic diseases?

  1. Atopy

  2. Epitope

  3. Virulence

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

Atopy is the condition which has been developed due to exposure to allergens in which the person is susceptible to allergic reactions. This is an inherited syndrome. The person is more likely to develop the allergic reactions like rash, rhinitis, asthma, etc when encountered with the allergen. 

Thus, the correct answer is option A.