Q.1 What is the study of medical genetics primarily concerned with?
The study of animal behavior
The study of human genes and genetic disorders
The study of microbial infections
The study of environmental toxins
Explanation - Medical genetics focuses on understanding human genes, heredity, and genetic disorders to improve diagnosis and treatment.
Correct answer is: The study of human genes and genetic disorders
Q.2 Which of the following is a chromosomal disorder?
Cystic fibrosis
Down syndrome
Sickle cell anemia
Huntington's disease
Explanation - Down syndrome is caused by an extra copy of chromosome 21 (trisomy 21), making it a chromosomal disorder.
Correct answer is: Down syndrome
Q.3 Which type of inheritance pattern does cystic fibrosis follow?
Autosomal dominant
Autosomal recessive
X-linked dominant
Mitochondrial
Explanation - Cystic fibrosis is inherited when an individual receives two defective CFTR alleles, one from each parent, following an autosomal recessive pattern.
Correct answer is: Autosomal recessive
Q.4 A karyotype showing 47 chromosomes indicates:
Normal female
Normal male
Trisomy
Monosomy
Explanation - Humans normally have 46 chromosomes; having 47 indicates an extra chromosome, which is a trisomy.
Correct answer is: Trisomy
Q.5 Which gene is mutated in Huntington's disease?
HTT gene
CFTR gene
BRCA1 gene
FMR1 gene
Explanation - Huntington's disease is caused by a mutation in the HTT gene, leading to progressive neurodegeneration.
Correct answer is: HTT gene
Q.6 Which of the following is an X-linked recessive disorder?
Duchenne muscular dystrophy
Marfan syndrome
Phenylketonuria
Tay-Sachs disease
Explanation - Duchenne muscular dystrophy is inherited via an X-linked recessive pattern, mostly affecting males.
Correct answer is: Duchenne muscular dystrophy
Q.7 Which molecular technique is commonly used to detect specific gene mutations?
PCR
ELISA
Western blot
Flow cytometry
Explanation - Polymerase Chain Reaction (PCR) amplifies specific DNA sequences and is widely used for detecting gene mutations.
Correct answer is: PCR
Q.8 Which genetic disorder is caused by a single nucleotide change in hemoglobin gene?
Thalassemia
Sickle cell anemia
Phenylketonuria
Cystic fibrosis
Explanation - Sickle cell anemia is caused by a point mutation in the β-globin gene, substituting valine for glutamic acid.
Correct answer is: Sickle cell anemia
Q.9 Mitochondrial inheritance is passed down primarily from:
Father
Mother
Both parents equally
Grandparents
Explanation - Mitochondrial DNA is inherited maternally because mitochondria in sperm are typically not transmitted to the offspring.
Correct answer is: Mother
Q.10 Which syndrome is caused by deletion of a portion of chromosome 5?
Cri-du-chat syndrome
Turner syndrome
Klinefelter syndrome
Angelman syndrome
Explanation - Cri-du-chat syndrome results from deletion of the short arm of chromosome 5 and is characterized by a high-pitched cry.
Correct answer is: Cri-du-chat syndrome
Q.11 Which of the following is a multifactorial genetic disorder?
Cystic fibrosis
Diabetes mellitus type 2
Huntington's disease
Duchenne muscular dystrophy
Explanation - Type 2 diabetes involves multiple genetic factors along with environmental triggers, making it multifactorial.
Correct answer is: Diabetes mellitus type 2
Q.12 Gene therapy aims to:
Replace or repair defective genes
Kill cancer cells
Improve blood circulation
Boost immune response non-specifically
Explanation - Gene therapy introduces functional genes to correct genetic defects or modify disease progression.
Correct answer is: Replace or repair defective genes
Q.13 Phenylketonuria (PKU) results from a mutation in which enzyme gene?
Phenylalanine hydroxylase
Tyrosinase
Hexosaminidase A
Glucose-6-phosphate dehydrogenase
Explanation - PKU is caused by mutations in the phenylalanine hydroxylase gene, leading to toxic accumulation of phenylalanine.
Correct answer is: Phenylalanine hydroxylase
Q.14 Which term describes two different alleles at a gene locus?
Homozygous
Heterozygous
Hemizygous
Monosomic
Explanation - Heterozygous refers to having two different alleles at a particular gene locus.
Correct answer is: Heterozygous
Q.15 Marfan syndrome primarily affects which tissue?
Connective tissue
Nervous tissue
Muscle tissue
Epithelial tissue
Explanation - Marfan syndrome is caused by mutations in the fibrillin-1 gene affecting connective tissue, leading to tall stature and cardiovascular anomalies.
Correct answer is: Connective tissue
Q.16 Which test is used to visualize chromosomal abnormalities?
Karyotyping
ELISA
PCR
Northern blot
Explanation - Karyotyping arranges chromosomes to detect structural and numerical abnormalities.
Correct answer is: Karyotyping
Q.17 Which genetic disorder is characterized by trinucleotide repeat expansion?
Huntington's disease
Cystic fibrosis
Down syndrome
Sickle cell anemia
Explanation - Huntington's disease is caused by CAG trinucleotide repeat expansion in the HTT gene.
Correct answer is: Huntington's disease
Q.18 Which type of mutation causes a premature stop codon?
Missense mutation
Nonsense mutation
Silent mutation
Frameshift mutation
Explanation - A nonsense mutation converts a codon into a stop codon, leading to truncated protein production.
Correct answer is: Nonsense mutation
Q.19 Klinefelter syndrome has which karyotype?
45,X
47,XXY
47,XYY
46,XY
Explanation - Klinefelter syndrome occurs in males with an extra X chromosome, resulting in a 47,XXY karyotype.
Correct answer is: 47,XXY
Q.20 Which is an example of an autosomal dominant disorder?
Huntington's disease
Cystic fibrosis
Phenylketonuria
Sickle cell anemia
Explanation - Huntington's disease manifests if just one copy of the defective allele is inherited, following autosomal dominant inheritance.
Correct answer is: Huntington's disease
Q.21 Fragile X syndrome is caused by:
Deletion in X chromosome
Trinucleotide repeat expansion
Mitochondrial mutation
Point mutation in BRCA1
Explanation - Fragile X syndrome results from CGG trinucleotide repeat expansion in the FMR1 gene on the X chromosome.
Correct answer is: Trinucleotide repeat expansion
Q.22 Which genetic disorder is screened using heel-prick test in newborns?
Cystic fibrosis
Phenylketonuria
Huntington's disease
Marfan syndrome
Explanation - Newborn screening via heel-prick can detect PKU early, allowing dietary intervention to prevent intellectual disability.
Correct answer is: Phenylketonuria
Q.23 Gene dosage imbalance is characteristic of:
Trisomy disorders
Point mutations
Mitochondrial disorders
Frameshift mutations
Explanation - Trisomy disorders, like Down syndrome, have extra chromosomes, leading to altered gene dosage and phenotypic effects.
Correct answer is: Trisomy disorders
Q.24 Which of the following is a biochemical genetic disorder?
Tay-Sachs disease
Down syndrome
Turner syndrome
Klinefelter syndrome
Explanation - Tay-Sachs disease is caused by a deficiency of the enzyme hexosaminidase A, affecting lipid metabolism.
Correct answer is: Tay-Sachs disease
Q.25 Which method can detect deletions, duplications, or rearrangements in chromosomes?
FISH
ELISA
Western blot
Northern blot
Explanation - Fluorescence in situ hybridization (FISH) uses fluorescent probes to detect chromosomal abnormalities at a molecular level.
Correct answer is: FISH