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
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AIDS
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Cystic fibrosis
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Tuberculosis
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Cortical dysplasia
B
Correct answer
Explanation
It is a genetic disease caused by a gene mutation. The gene controls the movement of salts and water into and out of the cells.The mutated form of the gene results in thick mucus to be secreted by the lungs, airways and pancreas, including many other symptoms. The mutated gene is recessive to the normal gene.
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hereditary nonpolyposis colon cancer
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familial adenomatous polyposis
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neurofibromatosis
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hereditary breast cancers
A
Correct answer
Explanation
Microsatellite instability results from aberrant mismatch repair and is characteristic of HNPCC.
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EGF receptor gene
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ABL oncogene
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Myc oncogene
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NF1 gene
A
Correct answer
Explanation
Approximately 10% of patients with non-small cell lung cancer respond to gefitinib, which is predicted by EGF receptor gene mutation.
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Gene amplification
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Chromosome translocation
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Missense mutation
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Nonsense mutation
D
Correct answer
Explanation
One expects a gain of function mutation in an oncogene, whereas nonsense mutation would result in loss of function.
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Transmitted as dominant traits in families.
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May be associated with loss of heterozygosity in tumors.
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Act dominantly in tumor cells.
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Associated with two-hit model of carcinogenesis.
C
Correct answer
Explanation
This statement is incorrect. The tumor suppressor genes does not act dominantly in tumor cells.
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Mongolism
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Colour blindness
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Haemophilia
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Down's syndrome
C
Correct answer
Explanation
Bleeder's disease is the common name for Haemophilia, a genetic disorder where blood doesn't clot properly due to deficiency of clotting factors (VIII or IX). Colour blindness, Down's syndrome (mongolism is an outdated term), and other genetic conditions mentioned are unrelated to bleeding disorders.
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Cancer
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Malaria
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Ulcer
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Haemophilia
A
Correct answer
Explanation
Cancer is caused due to mutations or defects in genes.
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females and expressed by females
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females and expressed by males
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males and expressed by females
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males and expressed by males
B
Correct answer
Explanation
Haemophilia is a hereditary disease carried by females and expressed by males.
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Leigh syndrome
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Myoneurogenic gastrointestinal encephalopathy
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Galactosialidosis
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X-linked adrenoleukodystrophy
D
Correct answer
Explanation
X-linked adrenoleukodystrophy is a peroxisomal disorder.
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increased number of trinucleotide gene repeats (CAG)
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mutation in gene for the protein cystic fibrosis trans-membrane conductance regulator or CFTR
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deficiency of the protein α1-anti-trypsin or A1-AT
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formation of insoluble amyloid protein
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none of the above
A
Correct answer
Explanation
Huntington disease is caused by increased number of trinucleotide gene repeats (CAG) leading to increased number of glutamine residues incorporated incorresponding protein.
D
Correct answer
Explanation
In humans, each cell normally contains 23 pairs of chromosomes for a total of 46. Twenty two of these pairs are called autosomes in both males and females.
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alkaptonuria and albinism
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albinism and sickle cell anemia
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hemophilia
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All of the above
D
Correct answer
Explanation
This is the correct option. Congenital disorder or congenital disease is a condition existing at birth and often before birth, regardless of causation. Of these diseases, those characterised by structural deformities are termed "congenital anomalies" and involve defects in or damage to a developing foetus.
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On chromosomes
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In endoplasmic reticulum
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In cytosol
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On nuclear membrane
A
Correct answer
Explanation
Genes are located on chromosomes inside the nucleus.
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Only 1
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Only 2
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Both 1 and 2
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Neither 1 nor 2
C
Correct answer
Explanation
Statement 1 is correct. Colour blindness is an inherited disorder, which is mainly transferred from father to son.
Statement 2 is also correct. The three given disorders are caused due to defective haemoglobin, which are transferred from mother to the fetus through blood.
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Alkaptonuria
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Epipermolysis bullosa
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Haemophilia B
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Hypertrichosis
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Phenylketonuria
D
Correct answer
Explanation
Hypertrichosis is an abnormal amount of hair growth over the body. It is Y-linked recessive disorder.