Genetics Trivia
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98 free Genetics trivia questions with answers — trivia quiz, new questions added Oct 2026.
Genetics began with a friar counting pea plants in a monastery garden, and it now lets scientists rewrite DNA letter by letter. Between those two points sit some of the best stories in science: a fruit fly with white eyes, a corn geneticist ignored for decades, a photograph shown without permission, and a sheep named after Dolly Parton. This quiz covers all of it. You'll be asked about Mendel's ratios and why nobody noticed them for 35 years, how many chromosomes humans really have (and who got it wrong for decades), what a codon is, which diseases are dominant and which recessive, and who won the Nobel Prizes along the way. There are questions on model organisms, sex determination in birds and platypuses, epigenetics, the Human Genome Project, and the first CRISPR medicine. The difficulty runs from high-school biology up to the kind of detail that separates a biology graduate from a keen reader. Fifty questions, every answer sourced. Start with the peas.
30 of 98 questions with answers and explanations. Play the quiz
Q 01Which shape did James Watson and Francis Crick propose for the structure of DNA in 1953?
Double helix
Double helix: months earlier Linus Pauling had proposed a triple helix for DNA, a model he soon saw was built inside out with the wrong number of strands.
Q 02Gregor Mendel belonged to which religious order?
Augustinians
Augustinians: Mendel joined their St Thomas's Abbey in Brno, and once he became abbot in 1868 his administrative duties largely ended his experiments.
Q 03Roughly how many plants did Mendel cultivate and test between 1856 and 1863?
28,000
28,000: most were garden peas, and when Mendel later tried hawkweed his results would not repeat, because hawkweed's seeds grow into clones of the mother plant.
Q 04Which naturalist died in 1882 without ever reading Gregor Mendel's work on pea hybrids?
Charles Darwin
Charles Darwin was unaware of Mendel's paper and tried instead to explain heredity with his own theory, pangenesis, which never worked out.
Q 05Who coined the word 'genetics' for the study of heredity?
William Bateson
William Bateson championed Mendel's rediscovered laws so fiercely against rivals such as W. F. R. Weldon that he was nicknamed 'Mendel's bulldog'.
Q 06Who introduced the word 'gene' for a unit of heredity?
Wilhelm Johannsen
Wilhelm Johannsen found that sowing only the biggest beans from a pure line didn't breed bigger beans, which led him to split genotype from phenotype.
Q 07What idealized phenotype ratio did Mendel find in monohybrid crosses?
3:1
3:1: R. A. Fisher later showed that many genes, each inherited in such ratios, add up to the smooth bell-curve variation seen in many traits.
Q 08Which principle explains why round green peas appeared in the second generation after Mendel crossed round yellow with wrinkled green?
Law of independent assortment
Law of independent assortment has a physical cause: chromosome pairs line up at random as sex cells form, so genes on different chromosomes are shuffled separately.
Q 09The Punnett square is named after a geneticist from which country?
Britain
Britain: Cambridge geneticist Reginald Punnett took a population puzzle to his cricket partner G. H. Hardy, whose answer became the Hardy–Weinberg principle.
Q 10Which base pairs with adenine in DNA?
Thymine
Thymine: Erwin Chargaff found DNA holds about as much adenine as thymine, a clue Watson and Crick explained by pairing the two bases.
Q 11Which inheritance pattern explains the AB blood type?
Codominance
Codominance puts both A and B markers on red blood cells, so AB plasma carries neither anti-A nor anti-B antibodies and can be given to patients of any blood group.
Q 12What term describes one gene masking the effect of another?
Epistasis
Epistasis is why a yellow Labrador can carry the gene for a black coat: two copies of a recessive e allele keep black pigment out of its fur.
Q 13Who showed that genes sit on chromosomes after spotting a white-eyed mutant male in 1910?
Thomas Hunt Morgan
Thomas Hunt Morgan had been skeptical of Mendel's laws, until the white-eyed trait proved to be sex-linked, tying a gene to a sex chromosome.
Q 21Which PhD student worked with Rosalind Franklin on the famous X-ray image 'Photo 51'?
Raymond Gosling
Raymond Gosling had started out under Maurice Wilkins, who later showed the image to James Watson.
Q 22Why could Rosalind Franklin not share the 1962 Nobel Prize for the structure of DNA?
She had died four years earlier
She had died four years earlier, and Nobel rules then barred awards to anyone not nominated while alive, so Watson, Crick and Wilkins shared it.
Q 23Which molecule carries a gene's instructions from the nucleus to the ribosomes?
Messenger RNA
Q 14Genes lying close together on a chromosome are rarely separated by which event during meiosis?
Crossing over
Crossing over separates distant genes more often than close ones, and undergraduate Alfred Sturtevant used those rates to draw the first genetic map.
Q 15Which insect is the model organism known by the name Drosophila melanogaster?
The fruit fly
The fruit fly breeds a new generation in about ten days, so geneticists can follow a trait through several generations within weeks.
Q 16The word 'chromosome', coined in 1888, literally means what?
Coloured body
Coloured body: the structures were named for how strongly they take up the dyes used to stain cells.
Q 17How many chromosomes does a typical human cell contain?
46
46: egg and sperm cells each carry a single set of 23, so fertilization restores the full set in every new human.
Q 18What is the name for an image of a cell's chromosomes arranged in pairs by size?
Karyotype
Karyotype: ones made with better techniques by Joe Hin Tjio and Albert Levan in the mid-1950s overturned a human chromosome count repeated for some 30 years.
Q 19Duplicated copies of a chromosome joined at the centromere are called what?
Sister chromatids
Sister chromatids are pulled to opposite ends of a dividing cell, so each daughter cell receives an identical copy of every chromosome.
Q 20Which bacteriologist studying pneumonia discovered bacterial 'transformation' in 1928?
Frederick Griffith
Frederick Griffith saw harmless pneumococci turn deadly when mixed with heat-killed virulent ones, and in 1944 Oswald Avery's team showed the transforming agent was DNA.
Messenger RNA is what the Pfizer–BioNTech and Moderna COVID-19 vaccines delivered, so cells briefly made the virus's surface protein and built immunity to it.
Q 24Which codon is the most common start signal, read as methionine?
AUG
AUG is where ribosomes begin translating, so nearly every newly made protein starts with methionine, or formylmethionine in bacteria and mitochondria.
Q 25Which inherited disorder did Queen Victoria pass into royal families across Europe?
Haemophilia
Haemophilia afflicted Russia's heir Alexei, and the imperial family came to rely on the mystic Rasputin, who seemed able to ease his bleeding.
Q 26Which enzyme, from a hot-spring bacterium, made PCR practical?
Taq polymerase
Taq polymerase comes from a bacterium first found in a Yellowstone hot spring, so it survives the high heat that separates DNA strands in each PCR cycle.
Q 27Who invented PCR in 1983?
Kary Mullis
Kary Mullis said the idea came to him on a Friday-night drive from Berkeley to his cabin in Mendocino, and it won him a share of the 1993 Nobel Prize in Chemistry.
Q 28Who developed chain-termination DNA sequencing in 1977?
Frederick Sanger
Frederick Sanger won his second Nobel Prize in Chemistry for it, yet he declined a knighthood because he did not want to be addressed as 'Sir'.
Q 29Which geneticist succeeded James Watson in 1993 as head of the Human Genome Project?
Francis Collins
Francis Collins led it under the Bermuda Principles, which had labs post new human DNA sequence publicly, preferably within 24 hours.
Q 30Which company launched a rival private human genome effort in 1998?
Celera Genomics
Celera Genomics vowed to finish years sooner, so the public Human Genome Project moved its own completion date forward to 2003.