Major Scientific Discoveries Practice Questions
20 free Major Scientific Discoveries practice questions for the General Science. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
In 1928, Alexander Fleming accidentally discovered the first true antibiotic while studying Staphylococcus bacteria. What was the name of this substance?
- A Streptomycin
- B Penicillin
- C Tetracycline
- D Neomycin
Correct answer: Penicillin
Fleming observed that a mold called Penicillium notatum created a bacteria-free zone on a culture plate. This discovery revolutionized medicine by providing a way to treat previously fatal bacterial infections.
Which scientist is credited with the discovery of the electron in 1897 through his experiments with cathode ray tubes?
- A Ernest Rutherford
- B J.J. Thomson
- C Niels Bohr
- D James Chadwick
Correct answer: J.J. Thomson
Thomson's experiments showed that cathode rays were composed of previously unknown negatively charged particles. This led to the 'plum pudding' model of the atom and the understanding of subatomic particles.
The structure of DNA was famously modeled as a double helix in 1953. While Watson and Crick are well known, which scientist's X-ray diffraction images were crucial to this discovery?
- A Marie Curie
- B Rosalind Franklin
- C Barbara McClintock
- D Dorothy Hodgkin
Correct answer: Rosalind Franklin
Franklin's 'Photo 51' provided the essential evidence for the helical structure of DNA. Her data on the B-form of DNA was used by Watson and Crick to build their accurate molecular model.
Who published the 'Special Theory of Relativity' in 1905, introducing the world to the mass-energy equivalence formula $E=mc^2$?
- A Isaac Newton
- B Max Planck
- C Albert Einstein
- D Stephen Hawking
Correct answer: Albert Einstein
Einstein's theory transformed our understanding of space, time, and gravity. He proposed that the laws of physics are the same for all non-accelerating observers and that the speed of light in a vacuum is constant.
Which discovery by Wilhelm Röntgen in 1895 allowed physicians to see inside the human body without surgery for the first time?
- A Ultrasound
- B Radar
- C X-rays
- D Gamma rays
Correct answer: X-rays
Röntgen discovered X-rays while experimenting with vacuum tubes, observing they could pass through human flesh but not bone. He received the first Nobel Prize in Physics for this monumental discovery in 1901.
In the 1860s, which scientist developed the process of heating liquids to kill harmful bacteria, now known as pasteurization?
- A Robert Koch
- B Louis Pasteur
- C Joseph Lister
- D Edward Jenner
Correct answer: Louis Pasteur
Pasteur proved that microorganisms cause spoilage and disease, effectively disproving the theory of spontaneous generation. His work laid the foundation for modern microbiology and food safety.
The first successful vaccine, created to combat smallpox in 1796, was developed by:
- A Jonas Salk
- B Albert Sabin
- C Edward Jenner
- D Louis Pasteur
Correct answer: Edward Jenner
Jenner observed that milkmaids who had caught cowpox were immune to smallpox. He used matter from cowpox lesions to inoculate a young boy, marking the birth of immunology.
Which astronomer was the first to use a telescope to observe the moons of Jupiter, providing evidence for the heliocentric model?
- A Nicolaus Copernicus
- B Johannes Kepler
- C Galileo Galilei
- D Tycho Brahe
Correct answer: Galileo Galilei
Galileo's discovery of the four largest moons of Jupiter showed that not everything in the universe revolved around the Earth. This challenged the prevailing geocentric view and supported Copernican theory.
Who is credited with discovering the laws of planetary motion, describing how planets move in elliptical orbits?
- A Isaac Newton
- B Johannes Kepler
- C Galileo Galilei
- D Edwin Hubble
Correct answer: Johannes Kepler
Kepler derived three laws of planetary motion based on the meticulous observations of Tycho Brahe. These laws accurately described the motion of planets and paved the way for Newton's law of universal gravitation.
In 1911, Ernest Rutherford conducted the Gold Foil Experiment, which led to the discovery of the:
- A Proton
- B Neutron
- C Atomic Nucleus
- D Electron Cloud
Correct answer: Atomic Nucleus
Rutherford observed that most alpha particles passed through the foil, but some were deflected at sharp angles. This led him to conclude that the atom's mass and positive charge are concentrated in a tiny, central nucleus.
Who discovered the first radioactive element, Polonium, along with Radium, and remains the only person to win Nobel Prizes in two different sciences?
- A Lise Meitner
- B Marie Curie
- C Irene Joliot-Curie
- D Otto Hahn
Correct answer: Marie Curie
Marie Curie pioneered research on radioactivity, a term she coined. She was awarded the Nobel Prize in Physics (1903) and Chemistry (1911) for her discoveries and isolation of radioactive isotopes.
In 1665, who first used the term 'cell' to describe the microscopic units he observed in a slice of cork?
- A Anton van Leeuwenhoek
- B Matthias Schleiden
- C Robert Brown
- D Robert Hooke
Correct answer: Robert Hooke
Hooke published his observations in 'Micrographia,' noting that the cork looked like 'Microscopical pores' or cells used by monks. While he was actually seeing dead plant cell walls, it initiated the field of cell biology.
The discovery of the 'Expansion of the Universe' by observing the redshift of distant galaxies was made by:
- A Albert Einstein
- B Stephen Hawking
- C Edwin Hubble
- D Carl Sagan
Correct answer: Edwin Hubble
In 1929, Hubble proved that the universe is expanding by showing that the farther away a galaxy is, the faster it appears to be moving away from us. This provided the observational basis for the Big Bang theory.
Which scientist is known as the 'Father of Genetics' for his work with pea plants and the discovery of the fundamental laws of inheritance?
- A Gregor Mendel
- B Charles Darwin
- C Thomas Hunt Morgan
- D Francis Crick
Correct answer: Gregor Mendel
Mendel's experiments established that traits are passed down through discrete 'factors' (now known as genes) that follow specific mathematical ratios. His work remained largely unnoticed until it was rediscovered in 1900.
The discovery of the neutron in 1932, which accounted for the nuclear mass that protons alone could not explain, was made by:
- A James Chadwick
- B Enrico Fermi
- C Werner Heisenberg
- D Niels Bohr
Correct answer: James Chadwick
Chadwick proved the existence of a neutral particle with roughly the same mass as a proton. This discovery allowed for the accurate calculation of atomic mass and the subsequent development of nuclear fission.
Who developed the first periodic table of elements in 1869, famously leaving gaps for elements that had not yet been discovered?
- A John Dalton
- B Antoine Lavoisier
- C Robert Boyle
- D Dmitri Mendeleev
Correct answer: Dmitri Mendeleev
Mendeleev organized elements by increasing atomic weight and periodic properties. His table's predictive power was confirmed when elements like Gallium and Germanium were later found with the properties he had described.
The circulation of blood through the human body was first accurately described in 1628 by:
- A William Harvey
- B Andreas Vesalius
- C Claudius Galen
- D Hippocrates
Correct answer: William Harvey
Harvey demonstrated that the heart acts as a pump and that blood flows in a continuous circuit through arteries and veins. This overturned centuries of belief that blood was consumed by tissues and constantly replenished.
Who discovered the Principle of Displacement (Eureka!) and calculated the value of Pi while working in Syracuse?
- A Pythagoras
- B Euclid
- C Aristotle
- D Archimedes
Correct answer: Archimedes
Archimedes discovered that the upward buoyant force on an object in a fluid is equal to the weight of the fluid it displaces. He was also a pioneer in using the method of exhaustion to calculate areas and volumes.
In 1945, the first electronic general-purpose computer was completed. What was its acronym?
- A ENIAC
- B UNIVAC
- C ALTAIR
- D EDSAC
Correct answer: ENIAC
ENIAC (Electronic Numerical Integrator and Computer) was built at the University of Pennsylvania. It was a massive machine capable of being reprogrammed to solve a wide range of computing problems.
Which scientist discovered Oxygen (independently of Scheele) and is often credited with the invention of carbonated water?
- A Joseph Priestley
- B Henry Cavendish
- C Antoine Lavoisier
- D Michael Faraday
Correct answer: Joseph Priestley
Priestley isolated several gases, including 'dephlogisticated air' (oxygen). His work on gases led him to discover that dissolving 'fixed air' (carbon dioxide) in water produced a refreshing, bubbly drink.