Genetics MCQs

  • What is the basic unit of heredity?
    a) Chromosome
    b) Gene
    c) DNA
    d) RNA
    Answer: b) Gene
  • What is the process of transferring genetic material from one generation to the next called?
    a) Mutation
    b) Genetic recombination
    c) Heredity
    d) Evolution
    Answer: c) Heredity
  • Which term describes the physical appearance or expression of a gene?
    a) Genotype
    b) Phenotype
    c) Allele
    d) Locus
    Answer: b) Phenotype
  • What are alternative forms of a gene called?
    a) Chromosomes
    b) Traits
    c) Alleles
    d) Genotypes
    Answer: c) Alleles
  • What is the genotype of an organism with two identical alleles for a particular trait?
    a) Heterozygous
    b) Homozygous
    c) Hemizygous
    d) Diploid
    Answer: b) Homozygous
  • What is the genotype of an organism with two different alleles for a particular trait?
    a) Heterozygous
    b) Homozygous
    c) Hemizygous
    d) Diploid
    Answer: a) Heterozygous
  • Which term refers to the genetic makeup of an organism?
    a) Phenotype
    b) Allele
    c) Genotype
    d) Trait
    Answer: c) Genotype
  • In a dihybrid cross, what is the expected phenotypic ratio for the F2 generation?
    a) 1:1
    b) 3:1
    c) 9:3:3:1
    d) 1:2:1
    Answer: c) 9:3:3:1
  • What is a Punnett square used to determine?
    a) The genotype of an organism
    b) The probability of offspring inheriting particular traits
    c) The physical traits of an organism
    d) The mutation rate in DNA
    Answer: b) The probability of offspring inheriting particular traits
  • Which law states that alleles for different traits are passed independently of one another?
    a) Law of Segregation
    b) Law of Independent Assortment
    c) Law of Dominance
    d) Law of Uniformity
    Answer: b) Law of Independent Assortment
  • What is the term for a genetic condition caused by the presence of an extra chromosome?
    a) Monosomy
    b) Trisomy
    c) Deletion
    d) Duplication
    Answer: b) Trisomy
  • Which genetic disorder is caused by a single gene mutation and characterized by the absence of an enzyme needed to break down phenylalanine?
    a) Cystic fibrosis
    b) Sickle cell anemia
    c) Phenylketonuria (PKU)
    d) Hemophilia
    Answer: c) Phenylketonuria (PKU)
  • What is a carrier in genetic terms?
    a) An individual who expresses a recessive trait
    b) An individual with two identical alleles for a trait
    c) An individual with one recessive and one dominant allele for a trait
    d) An individual with no genetic abnormalities
    Answer: c) An individual with one recessive and one dominant allele for a trait
  • Which type of inheritance pattern is characterized by the expression of both alleles in a heterozygote?
    a) Dominant inheritance
    b) Recessive inheritance
    c) Codominance
    d) Incomplete dominance
    Answer: c) Codominance
  • What does the term ‘complete dominance’ mean in genetics?
    a) Both alleles are expressed equally in the phenotype
    b) One allele completely masks the effect of another allele
    c) Both alleles contribute to the phenotype
    d) The phenotype is a blend of both alleles
    Answer: b) One allele completely masks the effect of another allele
  • Which type of mutation results in the substitution of one amino acid for another in a protein?
    a) Silent mutation
    b) Missense mutation
    c) Nonsense mutation
    d) Frameshift mutation
    Answer: b) Missense mutation
  • What is the role of DNA polymerase in DNA replication?
    a) To unwind the DNA double helix
    b) To synthesize new DNA strands
    c) To join Okazaki fragments
    d) To degrade RNA
    Answer: b) To synthesize new DNA strands
  • Which type of mutation results in the premature termination of a protein?
    a) Silent mutation
    b) Missense mutation
    c) Nonsense mutation
    d) Frameshift mutation
    Answer: c) Nonsense mutation
  • Which type of genetic variation involves the addition or deletion of nucleotides in a DNA sequence?
    a) Point mutation
    b) Frameshift mutation
    c) Silent mutation
    d) Missense mutation
    Answer: b) Frameshift mutation
  • What is a genotype?
    a) The physical appearance of an organism
    b) The genetic makeup of an organism
    c) The observable traits of an organism
    d) The environment of an organism
    Answer: b) The genetic makeup of an organism
  • Which process describes the exchange of genetic material between homologous chromosomes during meiosis?
    a) Crossing over
    b) Independent assortment
    c) Mutation
    d) Gene flow
    Answer: a) Crossing over
  • What is a karyotype?
    a) A visual representation of an organism’s genetic material
    b) The complete set of an organism’s genes
    c) The process of cell division
    d) The sequence of DNA nucleotides
    Answer: a) A visual representation of an organism’s genetic material
  • Which type of genetic analysis is used to determine the likelihood of inheriting a genetic disorder?
    a) Genetic screening
    b) Karyotyping
    c) Gene therapy
    d) PCR (Polymerase Chain Reaction)
    Answer: a) Genetic screening
  • What is the term for the genetic exchange between non-sister chromatids of homologous chromosomes?
    a) Genetic recombination
    b) Mutation
    c) Duplication
    d) Translocation
    Answer: a) Genetic recombination
  • Which genetic disorder is characterized by a deletion of a portion of the short arm of chromosome 5?
    a) Down syndrome
    b) Turner syndrome
    c) Cri du chat syndrome
    d) Klinefelter syndrome
    Answer: c) Cri du chat syndrome
  • Which type of inheritance pattern involves a trait being expressed in a heterozygote that is intermediate between the two homozygous phenotypes?
    a) Complete dominance
    b) Codominance
    c) Incomplete dominance
    d) Epistasis
    Answer: c) Incomplete dominance
  • What is the purpose of a test cross in genetics?
    a) To determine the genotype of an organism with a dominant phenotype
    b) To determine the presence of mutations
    c) To map genes on a chromosome
    d) To identify genetic disorders
    Answer: a) To determine the genotype of an organism with a dominant phenotype
  • Which process involves the transfer of genetic material from one bacterium to another through a plasmid?
    a) Conjugation
    b) Transformation
    c) Transduction
    d) Replication
    Answer: a) Conjugation
  • What is the purpose of gene therapy?
    a) To correct or replace defective genes
    b) To increase genetic variation
    c) To enhance gene expression
    d) To clone organisms
    Answer: a) To correct or replace defective genes
  • Which of the following describes the complete set of genes or genetic material present in a cell or organism?
    a) Genome
    b) Karyotype
    c) Transcriptome
    d) Epigenome
    Answer: a) Genome
  • What is the term for the condition where one gene affects the expression of another gene?
    a) Epistasis
    b) Codominance
    c) Incomplete dominance
    d) Pleiotropy
    Answer: a) Epistasis
  • Which of the following is an example of a sex-linked trait?
    a) Eye color
    b) Height
    c) Hemophilia
    d) Blood type
    Answer: c) Hemophilia
  • Which term describes the situation when an organism has three copies of a chromosome instead of the usual two?
    a) Monosomy
    b) Trisomy
    c) Tetrasomy
    d) Nullisomy
    Answer: b) Trisomy
  • What is the term for the random distribution of maternal and paternal chromosomes into gametes?
    a) Crossing over
    b) Independent assortment
    c) Mutation
    d) Gene flow
    Answer: b) Independent assortment
  • What is the main purpose of a pedigree chart?
    a) To track inheritance patterns of traits within a family
    b) To determine the genetic makeup of an individual
    c) To analyze gene expression levels
    d) To identify gene mutations
    Answer: a) To track inheritance patterns of traits within a family
  • Which type of genetic variation occurs due to a change in a single nucleotide base?
    a) Point mutation
    b) Inversion
    c) Duplication
    d) Translocation
    Answer: a) Point mutation
  • What is the term for the process by which a single gene influences multiple phenotypic traits?
    a) Pleiotropy
    b) Epistasis
    c) Polygenic inheritance
    d) Codominance
    Answer: a) Pleiotropy
  • Which genetic disorder is caused by a mutation in the CFTR gene and results in thick mucus production in the lungs?
    a) Sickle cell disease
    b) Cystic fibrosis
    c) Huntington’s disease
    d) Duchenne muscular dystrophy
    Answer: b) Cystic fibrosis
  • Which term describes the phenomenon where one gene can suppress or enhance the expression of another gene?
    a) Epistasis
    b) Codominance
    c) Incomplete dominance
    d) Polygenic inheritance
    Answer: a) Epistasis
  • What is the term for an observable characteristic of an organism that is determined by both genotype and environment?
    a) Phenotype
    b) Genotype
    c) Allele
    d) Trait
    Answer: a) Phenotype
  • Which term describes the exchange of genetic material between non-homologous chromosomes?
    a) Translocation
    b) Inversion
    c) Duplication
    d) Crossing over
    Answer: a) Translocation
  • Which type of genetic analysis is used to amplify specific DNA sequences?
    a) Gene therapy
    b) PCR (Polymerase Chain Reaction)
    c) Karyotyping
    d) Gel electrophoresis
    Answer: b) PCR (Polymerase Chain Reaction)
  • What is the term for the situation when one gene masks the effect of another gene at a different locus?
    a) Epistasis
    b) Codominance
    c) Incomplete dominance
    d) Pleiotropy
    Answer: a) Epistasis
  • Which genetic disorder is characterized by a change in a single nucleotide in the hemoglobin gene, leading to sickle-shaped red blood cells?
    a) Cystic fibrosis
    b) Sickle cell anemia
    c) Huntington’s disease
    d) Down syndrome
    Answer: b) Sickle cell anemia
  • What is the term for the condition where an organism has an abnormal number of chromosomes?
    a) Aneuploidy
    b) Polyploidy
    c) Monosomy
    d) Trisomy
    Answer: a) Aneuploidy
  • Which term describes the process by which genetic information is transferred from DNA to RNA?
    a) Transcription
    b) Translation
    c) Replication
    d) Mutation
    Answer: a) Transcription
  • What is the term for a genetic mutation that results in a segment of DNA being copied more than once?
    a) Duplication
    b) Deletion
    c) Inversion
    d) Translocation
    Answer: a) Duplication
  • Which of the following is an example of a recessive genetic disorder?
    a) Huntington’s disease
    b) Hemophilia
    c) Tay-Sachs disease
    d) Marfan syndrome
    Answer: c) Tay-Sachs disease
  • What is the term for the genetic process that involves the synthesis of proteins from mRNA templates?
    a) Translation
    b) Replication
    c) Transcription
    d) Splicing
    Answer: a) Translation
  • Which type of genetic mutation changes the number of copies of a particular gene or chromosomal segment?
    a) Duplication
    b) Inversion
    c) Translocation
    d) Point mutation
    Answer: a) Duplication