Genetics and Heredity MCQs 2026

Human gametes (sperm and egg) contain how many chromosomes

1. A23✓
2. B46✓
3. C22✓
4. D24✓

An organism whose genetic material has been altered using genetic engineering techniques is called a

1. AHybrid✓
2. BMutant✓
3. CClone✓
4. DGenetically Modified Organism (GMO)✓

A technique used to separate DNA fragments by size using an electric current is called

1. APCR✓
2. BKaryotyping✓
3. CGel electrophoresis✓
4. DCloning✓

The technique used to make millions of copies of a specific DNA segment in the laboratory is called

1. APolymerase Chain Reaction (PCR)✓
2. BGel electrophoresis✓
3. CDNA fingerprinting✓
4. DSouthern blotting✓

The non-coding sequences within a eukaryotic gene that are removed before translation are called

1. AExons✓
2. BIntrons✓
3. COperons✓
4. DPromoters✓

A sequence of three nucleotides on mRNA that specifies a particular amino acid is called a

1. AGene✓
2. BAllele✓
3. CIntron✓
4. DCodon✓

A segment of DNA that codes for a specific protein or functional RNA is called a

1. AGene✓
2. BCodon✓
3. CChromatid✓
4. DOperon✓

According to Chargaff's rule, the amount of adenine in DNA is approximately equal to the amount of

1. AGuanine✓
2. BCytosine✓
3. CThymine✓
4. DUracil✓

X-ray diffraction images crucial to solving DNA's structure were produced by

1. AErwin Chargaff✓
2. BRosalind Franklin✓
3. CBarbara McClintock✓
4. DThomas Morgan✓

The Hershey-Chase experiment using bacteriophages confirmed that the genetic material is

1. AProtein✓
2. BRNA✓
3. CLipid✓
4. DDNA✓

The experiment that first demonstrated bacterial transformation, later linked to DNA as the genetic material, was conducted by

1. AFrederick Griffith✓
2. BGregor Mendel✓
3. CThomas Morgan✓
4. DRosalind Franklin✓

Mendel's experiments were primarily conducted on which plant

1. AMaize✓
2. BFruit fly✓
3. CGarden pea✓
4. DTobacco✓

Traits controlled by multiple genes, such as human skin color and height, show

1. ASimple Mendelian inheritance✓
2. BPolygenic inheritance✓
3. CCodominant inheritance✓
4. DSex-linked inheritance✓

The phenomenon in which one gene masks or suppresses the expression of another gene at a different locus is called

1. ACodominance✓
2. BLinkage✓
3. CIncomplete dominance✓
4. DEpistasis✓

The exchange of genetic material between homologous chromosomes during meiosis is called

1. ACrossing over✓
2. BMutation✓
3. CTranslation✓
4. DDuplication✓

Genes located close together on the same chromosome that tend to be inherited together are said to show

1. AIndependent assortment✓
2. BLinkage✓
3. CCodominance✓
4. DEpistasis✓

A grid used to predict the possible genotypes of offspring from a genetic cross is called a

1. APedigree chart✓
2. BChromosome map✓
3. CPunnett square✓
4. DLinkage map✓

A diagram showing the inherited traits of a family across generations is called a

1. APedigree chart✓
2. BPunnett square✓
3. CKaryotype✓
4. DGene map✓

The complete set of genetic instructions of an organism is called its

1. APhenotype✓
2. BProteome✓
3. CKaryotype✓
4. DGenome✓

The physical, observable characteristics of an organism are collectively called its

1. AGenotype✓
2. BPhenotype✓
3. CKaryotype✓
4. DGenome✓

Color blindness in humans is most commonly inherited as a

1. AAutosomal dominant trait✓
2. BAutosomal recessive trait✓
3. CX-linked recessive trait✓
4. DY-linked trait✓

Cystic fibrosis is inherited in which pattern

1. AAutosomal recessive✓
2. BAutosomal dominant✓
3. CX-linked recessive✓
4. DY-linked✓

According to Mendel's Law of Segregation, allele pairs

1. Aseparate during gamete formation✓
2. Balways blend permanently✓
3. Cremain together in gametes✓
4. Dcombine to form new genes✓

The molecule that carries hereditary information in most living organisms is

1. ARNA✓
2. BDNA✓
3. CATP✓
4. DProtein✓

In a DNA molecule, adenine always pairs with

1. ACytosine✓
2. BGuanine✓
3. CUracil✓
4. DThymine✓

The scientists credited with discovering the double helix structure of DNA are

1. AMendel and Morgan✓
2. BGriffith and Avery✓
3. CWatson and Crick✓
4. DHershey and Chase✓

A cross between two heterozygous individuals for a single trait (Aa x Aa) typically produces offspring in the phenotypic ratio of

1. A1:2:1✓
2. B9:3:3:1✓
3. C3:1✓
4. D1:1✓

When neither allele is dominant and the heterozygote shows a blended phenotype, such as red and white flowers producing pink, this is called

1. AIncomplete dominance✓
2. BCodominance✓
3. CEpistasis✓
4. DPolygenic inheritance✓

Human blood type AB is an example of

1. AIncomplete dominance✓
2. BCodominance✓
3. CRecessive inheritance✓
4. DSex-linked inheritance✓

A person with genotype XhY, where Xh is the recessive hemophilia allele, will be

1. AA carrier female✓
2. BAn unaffected male✓
3. CAn affected female✓
4. DAn affected male✓

Down syndrome in humans is caused by

1. AAn extra copy of chromosome 21✓
2. BA missing X chromosome✓
3. CA point mutation in a single gene✓
4. DAn extra Y chromosome✓

Turner syndrome in females results from having

1. AAn extra chromosome 21✓
2. BOnly one X chromosome (XO)✓
3. CAn extra X chromosome (XXY)✓
4. DAn extra chromosome 18✓

Klinefelter syndrome is characterized by the karyotype

1. A45,XO✓
2. B47,XX,+21✓
3. C47,XXY✓
4. D46,XY✓

The process by which the genetic code on mRNA is used to synthesize a protein is called

1. AReplication✓
2. BTranscription✓
3. CTranslocation✓
4. DTranslation✓

The process of copying a DNA sequence into a complementary mRNA strand is called

1. ATranscription✓
2. BTranslation✓
3. CReplication✓
4. DReverse transcription✓

A change in the sequence of nucleotides in DNA is known as a

1. ACrossing over✓
2. BMutation✓
3. CRecombination✓
4. DTranslocation event✓

A mutation that inserts or deletes a number of nucleotides not divisible by three, shifting the reading frame, is called a

1. APoint mutation✓
2. BFrameshift mutation✓
3. CSilent mutation✓
4. DMissense mutation✓

A mutation that changes a codon but still codes for the same amino acid is called a

1. ANonsense mutation✓
2. BFrameshift mutation✓
3. CSilent mutation✓
4. DMissense mutation✓

Sickle cell anemia is caused by a mutation affecting the

1. AWhite blood cells✓
2. BBlood plasma proteins✓
3. CPlatelets✓
4. DBeta-globin chain of hemoglobin✓

The dihybrid cross ratio predicted by Mendel's Law of Independent Assortment in the F2 generation is

1. A3:1✓
2. B1:2:1✓
3. C9:3:3:1✓
4. D1:1:1:1✓

A cross involving two different traits simultaneously, such as seed shape and color, follows Mendel's Law of

1. ASegregation✓
2. BIndependent Assortment✓
3. CDominance✓
4. DLinkage✓

The flow of genetic information described as DNA to RNA to protein is known as the

1. ACentral Dogma of molecular biology✓
2. BLaw of independent assortment✓
3. CHardy-Weinberg equilibrium✓
4. DLamarckian theory✓

A visual representation of an individual's complete set of chromosomes, arranged by size and shape, is called a

1. AGenome map✓
2. BPedigree✓
3. CGene bank✓
4. DKaryotype✓

Thomas Hunt Morgan's work with fruit flies (Drosophila) provided key evidence for the

1. ACentral Dogma✓
2. BLaw of Segregation✓
3. CChromosomal theory of inheritance✓
4. DHardy-Weinberg principle✓

The father of modern genetics, known for his pea plant experiments, is

1. AGregor Mendel✓
2. BCharles Darwin✓
3. CThomas Morgan✓
4. DJames Watson✓

In a test cross, an organism showing the dominant phenotype is crossed with an organism that is

1. AHeterozygous dominant✓
2. BAlso showing the dominant phenotype✓
3. CSterile✓
4. DHomozygous recessive✓

An organism with two identical alleles for a given trait is said to be

1. AHeterozygous✓
2. BHomozygous✓
3. CHybrid✓
4. DDiploid only✓

The alternative forms of a gene found at the same locus on homologous chromosomes are called

1. AGenotypes✓
2. BPhenotypes✓
3. CAlleles✓
4. DLoci✓

A cell division process that produces four genetically different haploid daughter cells is called

1. AMitosis✓
2. BBinary fission✓
3. CCytokinesis✓
4. DMeiosis✓

The total number of chromosomes found in a normal human somatic cell is

1. A23✓
2. B46✓
3. C44✓
4. D48✓