Cell Biology & Genetics MCQs 2026

What is the term for a permanent change in an organism's DNA sequence

1. A Mutation ✓
2. B Transcription ✓
3. C Translation ✓
4. D Meiosis ✓

Who is regarded as the "Father of Modern Genetics" for his pea plant experiments establishing basic inheritance laws

1. A Charles Darwin ✓
2. B Gregor Mendel ✓
3. C James Watson ✓
4. D Francis Crick ✓

What term describes an organism's observable physical characteristics, resulting from genetic and environmental factors

1. A Genotype ✓
2. B Phenotype ✓
3. C Allele ✓
4. D Locus ✓

What term describes an organism's specific genetic makeup for a particular trait

1. A Genotype ✓
2. B Phenotype ✓
3. C Allele ✓
4. D Locus ✓

What term describes alternative forms of a gene that can exist at a specific location on a chromosome

1. A Genotype ✓
2. B Phenotype ✓
3. C Allele ✓
4. D Locus ✓

What term describes a trait that is expressed even when only one copy of the responsible allele is present

1. A Recessive trait ✓
2. B Dominant trait ✓
3. C Codominant trait ✓
4. D Sex-linked trait only ✓

What is the basic structural and functional unit of all living organisms

1. A Atom ✓
2. B Cell ✓
3. C Molecule ✓
4. D Tissue ✓

Which part of the cell contains genetic material and controls cell activities

1. A Mitochondria ✓
2. B Nucleus ✓
3. C Ribosome ✓
4. D Cell membrane ✓

Which cell organelle is known as the "powerhouse of the cell," responsible for energy production

1. A Nucleus ✓
2. B Mitochondria ✓
3. C Ribosome ✓
4. D Golgi apparatus ✓

Which cell structure is responsible for protein synthesis

1. A Nucleus ✓
2. B Mitochondria ✓
3. C Ribosome ✓
4. D Lysosome ✓

Which cell organelle modifies, sorts, and packages proteins for secretion or use within the cell

1. A Nucleus ✓
2. B Golgi apparatus ✓
3. C Ribosome ✓
4. D Mitochondria ✓

Which cell organelle contains digestive enzymes to break down waste materials and cellular debris

1. A Nucleus ✓
2. B Lysosome ✓
3. C Ribosome ✓
4. D Golgi apparatus ✓

Which structure surrounds and protects the cell, regulating what enters and exits

1. A Cell wall (plants only) ✓
2. B Cell membrane ✓
3. C Nucleus ✓
4. D Cytoplasm ✓

Which structure, found in plant cells but not animal cells, provides rigid structural support

1. A Cell membrane ✓
2. B Cell wall ✓
3. C Nucleus ✓
4. D Cytoplasm ✓

Which type of cell lacks a true nucleus and membrane-bound organelles, such as bacteria

1. A Eukaryotic cell ✓
2. B Prokaryotic cell ✓
3. C Plant cell ✓
4. D Animal cell ✓

Which type of cell has a true, membrane-bound nucleus and organelles, such as plant and animal cells

1. A Prokaryotic cell ✓
2. B Eukaryotic cell ✓
3. C Bacterial cell only ✓
4. D Viral cell ✓

Which organelle, found in plant cells, contains chlorophyll and conducts photosynthesis

1. A Mitochondria ✓
2. B Chloroplast ✓
3. C Ribosome ✓
4. D Lysosome ✓

What is the term for the jelly-like substance filling the cell, in which organelles are suspended

1. A Nucleus ✓
2. B Cytoplasm ✓
3. C Cell wall ✓
4. D Chromatin ✓

What is the molecule that carries genetic information in all living organisms

1. A DNA ✓
2. B RNA ✓
3. C Protein ✓
4. D ATP ✓

What shape does the DNA molecule characteristically form

1. A Single strand ✓
2. B Double helix ✓
3. C Triple helix ✓
4. D Circular loop only ✓

What are the four nitrogenous bases found in DNA

1. A Adenine, Guanine, Cytosine, Thymine ✓
2. B Adenine, Guanine, Cytosine, Uracil ✓
3. C Adenine, Thymine, Uracil, Guanine ✓
4. D Cytosine, Guanine, Uracil, Thymine ✓

Which nitrogenous base found in RNA replaces Thymine, which is found in DNA

1. A Adenine ✓
2. B Guanine ✓
3. C Cytosine ✓
4. D Uracil ✓

What is the term for a segment of DNA that codes for a specific protein or trait

1. A Chromosome ✓
2. B Gene ✓
3. C Ribosome ✓
4. D Nucleotide ✓

What is the term for the thread-like structures made of tightly coiled DNA, found within the nucleus

1. A Genes ✓
2. B Chromosomes ✓
3. C Ribosomes ✓
4. D Nucleotides ✓

How many chromosomes are typically found in a normal human somatic (body) cell

1. A 23 ✓
2. B 44 ✓
3. C 46 ✓
4. D 48 ✓

How many pairs of chromosomes are found in a normal human somatic cell

1. A 21 pairs ✓
2. B 22 pairs ✓
3. C 23 pairs ✓
4. D 24 pairs ✓

How many chromosomes are typically found in human reproductive cells (sperm or egg)

1. A 23 ✓
2. B 46 ✓
3. C 44 ✓
4. D 48 ✓

Which pair of chromosomes determines biological sex in humans

1. A Chromosome pair 1 ✓
2. B Chromosome pair 21 ✓
3. C The X and Y sex chromosomes ✓
4. D Chromosome pair 23 specifically referring to sex chromosomes ✓

What term describes a trait that is only expressed when two copies of the responsible allele are present

1. A Dominant trait ✓
2. B Recessive trait ✓
3. C Codominant trait ✓
4. D Polygenic trait ✓

What combination of sex chromosomes typically results in a biologically male individual

1. A XX ✓
2. B XY ✓
3. C XXY only ✓
4. D YY ✓

What combination of sex chromosomes typically results in a biologically female individual

1. A XX ✓
2. B XY ✓
3. C YY ✓
4. D XO only ✓

What is the process called by which a cell divides to produce two genetically identical daughter cells

1. A Mitosis ✓
2. B Meiosis ✓
3. C Fertilization ✓
4. D Transcription ✓

What is the process called by which reproductive cells divide to produce gametes with half the chromosome number

1. A Mitosis ✓
2. B Meiosis ✓
3. C Fertilization ✓
4. D Translation ✓

What is the process by which DNA information is copied into messenger RNA

1. A Translation ✓
2. B Transcription ✓
3. C Replication ✓
4. D Mutation ✓

What is the process by which messenger RNA is used to synthesize a protein

1. A Transcription ✓
2. B Translation ✓
3. C Replication ✓
4. D Mitosis ✓

What major international scientific effort, completed in 2003, mapped the complete human genome

1. A Human Genome Project ✓
2. B CRISPR Project ✓
3. C Manhattan Project ✓
4. D Apollo Project ✓

What is the term for the complete set of genetic material (DNA) present in an organism

1. A Genome ✓
2. B Genotype ✓
3. C Phenotype ✓
4. D Chromatin ✓

What term describes the large-scale study of an organism's complete set of proteins

1. A Genomics ✓
2. B Epigenetics ✓
3. C Proteomics ✓
4. D Metabolomics ✓

What term describes the study of how environmental factors can influence gene expression without altering the underlying DNA sequence

1. A Genomics ✓
2. B Epigenetics ✓
3. C Proteomics ✓
4. D Bioinformatics ✓

Who received a Nobel Prize for developing the technique to create induced pluripotent stem cells

1. A Shinya Yamanaka ✓
2. B James Watson ✓
3. C Francis Crick ✓
4. D Rosalind Franklin ✓

What term describes cells reprogrammed in the laboratory to behave like embryonic stem cells, avoiding some ethical concerns

1. A Adult stem cells ✓
2. B Induced pluripotent stem cells (iPSCs) ✓
3. C Totipotent cells ✓
4. D Gametes ✓

What term describes stem cells found in specific adult tissues, generally more limited in the cell types they can become

1. A Embryonic stem cells ✓
2. B Adult (somatic) stem cells ✓
3. C Totipotent cells ✓
4. D Zygote cells ✓

Which type of stem cell has the potential to develop into virtually any type of cell in the body

1. A Adult stem cells (more limited potential) ✓
2. B Embryonic stem cells ✓
3. C Skin cells (not stem cells) ✓
4. D Red blood cells (not stem cells) ✓

What is the term for a genetic test used to establish biological relationships, such as paternity

1. A DNA fingerprinting/profiling ✓
2. B PCR alone ✓
3. C Gel electrophoresis alone ✓
4. D Karyotyping ✓

What laboratory technique separates DNA fragments based on size using an electric current through a gel medium

1. A PCR ✓
2. B Gel electrophoresis ✓
3. C CRISPR ✓
4. D Karyotyping ✓

What laboratory technique is commonly used to amplify small segments of DNA for analysis

1. A PCR (Polymerase Chain Reaction) ✓
2. B Gel electrophoresis (separates, does not amplify) ✓
3. C CRISPR ✓
4. D Southern blotting ✓

What term describes a cross between two organisms differing in two traits, used to study inheritance patterns

1. A Monohybrid cross ✓
2. B Dihybrid cross ✓
3. C Test cross ✓
4. D Backcross ✓

What term describes a cross between two organisms differing in only one trait

1. A Monohybrid cross ✓
2. B Dihybrid cross ✓
3. C Test cross ✓
4. D Backcross ✓

What visual tool is commonly used in genetics to predict the probability of offspring genotypes from a cross

1. A Punnett square ✓
2. B Pedigree chart ✓
3. C Karyotype ✓
4. D Phylogenetic tree ✓

What term describes a chart used to trace the inheritance of a particular trait through a family across generations

1. A Punnett square ✓
2. B Pedigree chart ✓
3. C Karyotype ✓
4. D Genome map ✓

What term describes a visual representation showing the complete set of chromosomes in a cell, organized by size and shape

1. A Punnett square ✓
2. B Pedigree chart ✓
3. C Karyotype ✓
4. D Genotype chart ✓

Which genetic disorder results from an extra copy of chromosome 21, causing distinctive physical and developmental characteristics

1. A Down syndrome ✓
2. B Turner syndrome ✓
3. C Klinefelter syndrome ✓
4. D Cystic fibrosis ✓

Which genetic disorder specifically affects females, resulting from a missing or partially missing X chromosome

1. A Down syndrome ✓
2. B Turner syndrome ✓
3. C Klinefelter syndrome ✓
4. D Huntington's disease ✓

Which genetic disorder specifically affects males, resulting from an extra X chromosome (XXY)

1. A Down syndrome ✓
2. B Turner syndrome ✓
3. C Klinefelter syndrome ✓
4. D Sickle cell disease ✓

Which inherited disorder causes thick, sticky mucus buildup, particularly affecting the lungs and digestive system

1. A Cystic fibrosis ✓
2. B Sickle cell disease ✓
3. C Huntington's disease ✓
4. D Hemophilia ✓

Which inherited neurological disorder causes progressive brain cell degeneration, typically appearing in mid-adulthood

1. A Cystic fibrosis ✓
2. B Sickle cell disease ✓
3. C Huntington's disease ✓
4. D Down syndrome ✓

What term describes traits carried on the X chromosome, often showing different inheritance patterns between males and females

1. A Autosomal traits ✓
2. B Sex-linked traits ✓
3. C Polygenic traits ✓
4. D Codominant traits ✓

Colorblindness is a classic example of which type of inherited trait

1. A Autosomal dominant ✓
2. B Sex-linked recessive ✓
3. C Codominant ✓
4. D Polygenic ✓

What term describes a trait controlled by multiple genes, resulting in a continuous range of phenotypes, such as human height

1. A Monogenic trait ✓
2. B Polygenic trait ✓
3. C Sex-linked trait ✓
4. D Recessive trait ✓

What term describes a situation where both alleles for a trait are fully and simultaneously expressed, such as in certain blood types

1. A Complete dominance ✓
2. B Codominance ✓
3. C Incomplete dominance ✓
4. D Polygenic inheritance ✓

What term describes a situation where neither allele is completely dominant, resulting in a blended phenotype

1. A Complete dominance ✓
2. B Codominance ✓
3. C Incomplete dominance ✓
4. D Polygenic inheritance ✓

What field of biotechnology involves directly manipulating an organism's genes, such as inserting a gene from one species into another

1. A Genetic engineering ✓
2. B Selective breeding ✓
3. C Natural selection ✓
4. D Cloning (related but distinct concept) ✓

What term describes the process of creating a genetically identical copy of an organism

1. A Genetic engineering ✓
2. B Selective breeding ✓
3. C Cloning ✓
4. D Hybridization ✓

Which famous cloned mammal, created in 1996, was the first cloned from an adult somatic cell

1. A Dolly the sheep ✓
2. B Bessie the cow ✓
3. C Snuppy the dog ✓
4. D CC the cat ✓

What revolutionary gene-editing technology, developed in the 2010s, allows precise modification of DNA sequences

1. A CRISPR-Cas9 ✓
2. B PCR (Polymerase Chain Reaction) ✓
3. C Gel electrophoresis ✓
4. D Southern blotting ✓

What is the term for an organism that has two different alleles for a particular trait

1. A Heterozygous ✓
2. B Homozygous ✓
3. C Hemizygous ✓
4. D Polyzygous ✓

What is the term for an organism that has two identical alleles for a particular trait

1. A Heterozygous ✓
2. B Homozygous ✓
3. C Hemizygous ✓
4. D Polyzygous ✓

What enzyme can extend telomeres, notably active in stem cells and often reactivated abnormally in cancer cells

1. A Telomerase ✓
2. B DNA polymerase (general replication enzyme) ✓
3. C RNA polymerase ✓
4. D Helicase ✓

What is the general term for the orderly sequence of growth, DNA replication, and division that a cell undergoes

1. A Cell cycle ✓
2. B Metabolism ✓
3. C Homeostasis ✓
4. D Mitosis (a phase within the broader cycle) ✓

What is the term for the specific location of a gene on a chromosome

1. A Genotype ✓
2. B Locus ✓
3. C Allele ✓
4. D Phenotype ✓

What is the term for the protective cap-like structures found at the ends of chromosomes, preventing degradation

1. A Centromere ✓
2. B Telomere ✓
3. C Nucleolus ✓
4. D Chromatin ✓

What term describes the shortening of telomeres over successive cell divisions, associated with cellular aging

1. A Telomere elongation ✓
2. B Telomere shortening (Telomere attrition) ✓
3. C Chromatin condensation ✓
4. D Centromere duplication ✓

What principle states that alleles for different traits are distributed to gametes independently of each other

1. A Law of Segregation ✓
2. B Law of Independent Assortment ✓
3. C Law of Dominance ✓
4. D Law of Codominance ✓

What is the term for the exchange of genetic material between homozygous chromosomes during meiosis, increasing genetic diversity

1. A Independent assortment ✓
2. B Linked genes ✓
3. C Crossing over ✓
4. D Mutation ✓

What principle states that allele pairs separate during gamete formation, so each gamete carries only one allele for each trait

1. A Law of Segregation ✓
2. B Law of Independent Assortment ✓
3. C Law of Dominance ✓
4. D Law of Linkage ✓

What is the term for the study of how traits are passed from parents to offspring

1. A Genetics ✓
2. B Ecology ✓
3. C Taxonomy ✓
4. D Physiology ✓

What is the term describing genes located on the same chromosome that tend to be inherited together

1. A Independent assortment ✓
2. B Linked genes ✓
3. C Crossing over ✓
4. D Recombination ✓

What is the term for a change in the number of chromosomes in a cell, such as trisomy conditions like Down syndrome

1. A Point mutation ✓
2. B Chromosomal mutation (Aneuploidy) ✓
3. C Frameshift mutation ✓
4. D Silent mutation ✓

What is the term for a mutation involving a change in a single nucleotide base in the DNA sequence

1. A Point mutation ✓
2. B Chromosomal mutation ✓
3. C Frameshift mutation (specific type) ✓
4. D Deletion mutation (general category) ✓

What is the term for a mutation that inserts or deletes nucleotides, shifting the reading frame of the genetic code

1. A Point mutation ✓
2. B Chromosomal mutation ✓
3. C Frameshift mutation ✓
4. D Silent mutation ✓

What is the term for a mutation that does not change the resulting amino acid due to the redundancy of the genetic code

1. A Point mutation (general) ✓
2. B Frameshift mutation ✓
3. C Silent mutation ✓
4. D Nonsense mutation ✓

What is the term for a mutation that creates a premature stop codon, truncating protein production

1. A Point mutation (general) ✓
2. B Silent mutation ✓
3. C Nonsense mutation ✓
4. D Missense mutation (different effect) ✓

What is the term for a mutation that changes one amino acid to a different amino acid in the resulting protein

1. A Silent mutation ✓
2. B Nonsense mutation ✓
3. C Missense mutation ✓
4. D Frameshift mutation ✓

What is the term for external factors, such as radiation or certain chemicals, that can cause mutations

1. A Mutagens ✓
2. B Carcinogens (specifically cancer-causing subset) ✓
3. C Pathogens ✓
4. D Allergens ✓

What is the term for substances specifically known to cause cancer, often by causing mutations

1. A Mutagens (broader category) ✓
2. B Carcinogens ✓
3. C Pathogens ✓
4. D Teratogens (cause birth defects specifically) ✓

What is the term for a substance that can cause developmental abnormalities or birth defects in a developing embryo/fetus

1. A Mutagen (general) ✓
2. B Carcinogen (cancer-specific) ✓
3. C Pathogen ✓
4. D Teratogen ✓

What is the term for the complete biochemical machinery within a cell that carries out protein synthesis, involving ribosomes and RNA

1. A Translation apparatus/machinery ✓
2. B Replication fork ✓
3. C Nucleolus (specific structure) ✓
4. D Golgi complex ✓

What is the structure within the nucleus specifically responsible for producing ribosomal RNA and assembling ribosomes

1. A Nucleolus ✓
2. B Nuclear envelope ✓
3. C Chromatin ✓
4. D Nuclear pore ✓

What is the term for the loosely packed form of DNA and proteins found within the nucleus during non-dividing phases of the cell cycle

1. A Chromosome (condensed form) ✓
2. B Chromatin ✓
3. C Nucleolus ✓
4. D Centromere ✓

What is the term for the constricted region of a chromosome where sister chromatids are joined during cell division

1. A Telomere ✓
2. B Centromere ✓
3. C Nucleolus ✓
4. D Chromatin ✓

What is the term for the specific sequence of three nucleotide bases in mRNA that codes for a particular amino acid

1. A Codon ✓
2. B Anticodon ✓
3. C Gene ✓
4. D Allele ✓

What is the term for the complementary three-base sequence on tRNA that pairs with a codon during translation

1. A Codon ✓
2. B Anticodon ✓
3. C Gene ✓
4. D Locus ✓

How many different amino acids are commonly used to build proteins in living organisms

1. A 10 ✓
2. B 15 ✓
3. C 20 ✓
4. D 25 ✓

What is the specific codon that signals the start of protein synthesis during translation

1. A AUG ✓
2. B UAA ✓
3. C UAG ✓
4. D UGA ✓

How many stop codons signal the termination of protein synthesis

1. A One ✓
2. B Two ✓
3. C Three ✓
4. D Four ✓

How many divisions occur during meiosis, distinguishing it from the single division of mitosis

1. A One ✓
2. B Two ✓
3. C Three ✓
4. D Four ✓

During which sub-phase of interphase does DNA replication specifically occur

1. A G1 phase ✓
2. B S phase ✓
3. C G2 phase ✓
4. D M phase (mitosis itself) ✓

What are the three sub-phases of interphase called

1. A G1, S, and G2 phases ✓
2. B Prophase, Metaphase, Anaphase ✓
3. C Mitosis, Meiosis, Cytokinesis ✓
4. D Alpha, Beta, Gamma phases ✓

What is the term for the phase of the cell cycle where the cell grows and DNA replication occurs, before mitosis begins

1. A Interphase ✓
2. B Mitosis ✓
3. C Cytokinesis ✓
4. D Meiosis ✓

What is the final stage following telophase, during which the cytoplasm actually divides into two separate cells

1. A Interphase ✓
2. B Cytokinesis ✓
3. C Prophase (of next cycle) ✓
4. D Metaphase (of next cycle) ✓

During which phase of mitosis does the nuclear membrane reform and the cell begins to divide into two

1. A Prophase ✓
2. B Metaphase ✓
3. C Anaphase ✓
4. D Telophase ✓

During which phase of mitosis do sister chromatids separate and move to opposite poles of the cell

1. A Prophase ✓
2. B Metaphase ✓
3. C Anaphase ✓
4. D Telophase ✓

During which phase of mitosis do chromosomes align at the cell's equatorial plate (middle)

1. A Prophase ✓
2. B Metaphase ✓
3. C Anaphase ✓
4. D Telophase ✓

What is the term for the four phases of mitosis, in correct sequential order

1. A Prophase, Metaphase, Anaphase, Telophase ✓
2. B Metaphase, Prophase, Telophase, Anaphase ✓
3. C Anaphase, Telophase, Prophase, Metaphase ✓
4. D Telophase, Anaphase, Metaphase, Prophase ✓

What term describes cells with only a single set of chromosomes, such as human gametes with 23 chromosomes

1. A Haploid ✓
2. B Diploid ✓
3. C Triploid ✓
4. D Polyploid ✓

What term describes cells with a full set of paired chromosomes, such as human somatic cells with 46 chromosomes

1. A Haploid ✓
2. B Diploid ✓
3. C Triploid ✓
4. D Polyploid ✓

What is the term for the cell formed immediately after fertilization, when a sperm and egg combine

1. A Gamete ✓
2. B Zygote ✓
3. C Somatic cell ✓
4. D Blastocyst (a later developmental stage) ✓

What is the term for the resulting cells of meiosis, specifically referring to sperm and egg cells

1. A Somatic cells ✓
2. B Gametes ✓
3. C Zygotes ✓
4. D Stem cells ✓

What is the term for an organism's complete genetic blueprint, encoded within its DNA

1. A Genome ✓
2. B Proteome ✓
3. C Transcriptome ✓
4. D Metabolome ✓

What is the term for the complete set of RNA transcripts produced by an organism's genome at a given time

1. A Genome ✓
2. B Proteome ✓
3. C Transcriptome ✓
4. D Metabolome ✓

What is the general scientific field involving the collection, storage, and analysis of large-scale biological data, such as genomic sequences

1. A Genomics ✓
2. B Bioinformatics ✓
3. C Biochemistry ✓
4. D Biophysics ✓

What structural protein, wrapped by DNA, helps package and organize chromatin within the nucleus

1. A Histone ✓
2. B Keratin ✓
3. C Collagen ✓
4. D Actin ✓

What is the term for the process by which a cell becomes specialized to perform specific functions, such as becoming a muscle or nerve cell

1. A Differentiation ✓
2. B Replication ✓
3. C Mutation ✓
4. D Transcription ✓

What term describes a stem cell's capacity to develop into any cell type in the body, including extraembryonic tissues, characteristic of a fertilized egg

1. A Pluripotent ✓
2. B Totipotent ✓
3. C Multipotent ✓
4. D Unipotent ✓

What term describes a stem cell's more limited capacity to develop into a restricted range of related cell types, such as blood stem cells

1. A Pluripotent ✓
2. B Totipotent ✓
3. C Multipotent ✓
4. D Unipotent ✓

Which scientist is credited with the "one gene, one enzyme" hypothesis, foundational to understanding gene function

1. A George Beadle and Edward Tatum ✓
2. B James Watson and Francis Crick ✓
3. C Gregor Mendel ✓
4. D Rosalind Franklin ✓