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50 free Genetics trivia questions with answers — trivia quiz, new questions added Aug 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 50 questions with answers and explanations. Play the quiz
Q 01Who traced inheritance patterns in pea plants and is called the founder of modern genetics?
Gregor Mendel
Mendel presented his pea results in Brno in 1865; Darwin never read the paper.
Q 02Mendel belonged to which religious order?
Augustinians
He entered St Thomas's Abbey in Brno on his physics teacher's advice and later became its abbot.
Q 03Roughly how many plants did Mendel cultivate and test between 1856 and 1863?
28,000
Most were pea plants, Pisum sativum, chosen because their traits came in clear either/or forms.
Q 04In which year was Mendel's work rediscovered by de Vries, Correns and von Tschermak?
1900
Three botanists independently reached the same conclusions and then found Mendel had beaten them by 35 years.
Q 05Who coined the word 'genetics' in 1905?
William Bateson
He took it from the Greek genetikos and popularized it at a plant hybridization conference in London the next year.
Q 06Who introduced the term 'gene' in 1909?
Wilhelm Johannsen
Johannsen also drew the distinction between genotype and phenotype that biology still uses.
Q 07What idealized phenotype ratio did Mendel find in monohybrid crosses?
3:1
Three dominant to one recessive among the F2 generation; the two-trait dihybrid cross gives 9:3:3:1.
Q 08Which Mendelian law says alleles for separate traits are passed on independently?
Law of independent assortment
It holds for genes on different chromosomes; linked genes on the same chromosome break the rule.
Q 09The Punnett square is named after a geneticist from which country?
Britain
Reginald Punnett co-founded the Journal of Genetics with Bateson and also played cricket with the mathematician G. H. Hardy.
Q 10The word 'allele' is a short form of which older term?
Allelomorph
Bateson and Edith Rebecca Saunders coined it in the early 1900s to mean 'other form' of a gene.
Q 11What is it called when both alleles are expressed at once, as in AB blood type?
Codominance
Incomplete dominance instead gives an intermediate phenotype, like pink flowers from red and white parents.
Q 12What term describes one gene masking the effect of another?
Epistasis
A classic example is the gene for albinism hiding whatever coat colour genes an animal carries.
Q 13Who argued in 1911 that genes sit on chromosomes, based on white-eyed fruit flies?
Thomas Hunt Morgan
His Columbia 'Fly Room' went on to produce the first chromosome maps and a 1933 Nobel Prize.
Q 21Who actually took the famous X-ray image 'Photo 51' in Rosalind Franklin's lab?
Raymond Gosling
Gosling was Franklin's PhD student; Wilkins later showed the image to Watson without her permission.
Q 22Rosalind Franklin died in 1958 at what age?
37
Ovarian cancer killed her four years before Watson, Crick and Wilkins shared the Nobel Prize.
Q 23A group of three nucleotides that specifies one amino acid is called what?
A codon
Four bases read three at a time give 64 combinations to cover just 20 amino acids plus stop signals.
Which codon is the most common start signal, read as methionine?
Q 14Which of Morgan's students showed in 1913 that genes are arranged linearly on a chromosome?
Alfred Sturtevant
He built the first genetic map overnight as an undergraduate, using linkage frequencies to order the genes.
Q 15Which insect is the model organism known by the name Drosophila melanogaster?
The fruit fly
Cheap, fast-breeding and with giant salivary chromosomes, it has been a genetics workhorse for over a century.
Q 16Who coined the term 'chromosome' in 1888?
Heinrich Wilhelm Waldeyer
It means 'coloured body' — chromosomes are only visible once stained, which is why Flemming's 'chromatin' came first.
Q 17How many chromosomes does a typical human cell contain?
46
That is 22 pairs of autosomes plus one pair of sex chromosomes.
Q 18In which year was the correct human chromosome number finally established?
1956
Textbooks had said 48 for three decades, repeating Theophilus Painter's error, until Joe Hin Tjio counted 46.
Q 19Duplicated copies of a chromosome joined at the centromere are called what?
Sister chromatids
They form the familiar X shape seen in karyotypes, which only exists briefly before cell division.
Q 20Who discovered bacterial 'transformation' in 1928?
Frederick Griffith
Dead pneumococci passed something to live ones; Avery, MacLeod and McCarty showed in 1944 that something was DNA.
AUG
In bacteria and mitochondria it is read as formylmethionine instead.
Q 25Two of the three stop codons were given which colour-themed names?
Ochre and opal
The first, 'amber', was a pun on discoverer Harris Bernstein's surname, so the others kept the colour theme.
Q 26Khorana, Holley and Nirenberg shared a Nobel Prize in which year for deciphering the genetic code?
1968
Nirenberg and Leder had shown the triplet nature of the code; Khorana filled in the remaining codons.
Q 27Which enzyme, from a hot-spring bacterium, made PCR practical?
Taq polymerase
Thermus aquaticus thrives at 50-80 °C, so its polymerase survives the heating cycles that denature DNA.
Q 28Who invented PCR in 1983?
Kary Mullis
He shared the 1993 Nobel Prize in Chemistry with Michael Smith, seven years after Cetus first made PCR work.
Q 29Chain-termination DNA sequencing was developed in 1977 by whom?
Frederick Sanger
It earned Sanger his second Nobel Prize in Chemistry; the first was for sequencing insulin.
Q 30In which year was the Human Genome Project officially launched?
1990
Planned from 1984, it ran 13 years and was declared complete in 2003 — 50 years after the double helix.