Quiz on Spontaneous Generation

Franceso Redi's

First tested the idea that flies arose spontantaeously He hypothesized that only flies produced flies; observed that maggots only appeared in flasks with flies, and not in closed-off flasks, proving his hypothesis correct; results were not convincing to others. An Italian scientist who set out to prove that living things came only from other living things.

John Neeham - 1745

Heated broth in sealed flasks. The broth became cloudy with microorganisms. He thought they developed spontaneously from the broth. He was wrong.

Pasteur's Experiment - 1859

Louis Pasteur - French microbiologist and chemist, experimented in mid-1800s; thought that biogenesis was true for microorganisms as well; filled swan-necked flasks with sterile nutrient broth; upright flasks only allowed air to contact broth, tilted flasks allowed microorganisms to contact broth as well; microorganisms grew in tilted-flask broth, proved that microorganisms do not appear spontaneously.

Stanley Miller and Harold Urey Experiment - 1953

Stanley Miller and Harold Urey - American scientists, experimented in 1953; built a glass apparatus to simulate early Earth conditions hypothesized by Oparin, filled apparatus with water and gases believed to have made up early atmosphere; boiled water and simulated lightning as energy source by discharging electricity; found that living things can produce chemicals.

Spontaneous Generation

The belief that living things developed from nonliving things.

biogenesis

theory that states that only living organisms can produce other living organisms, commonly accepted today

Francesco Redi - 1668

-first to attempt to disprove the theory of Spontaneous Generation - performed an experiments to see if maggots come from decaying meat left meat in jars, left half covered, other uncovered -maggots only came from the uncovered jars Since the flies could not land on the meat in the covered jars, they could not lay eggs on that meat, and no maggots formed -Redi concluded that the maggots did not come from the meat, but from eggs that flies laid on the meat Disproved spontaneous generation

Alexander Oparin - 1924

-hypothesized that energy from the sun, lighting and earth's heat triggered chemical reactions early in earth's history. There was no oxygen. He thought that early earth had no oxygen, but had gasses (ammonia, hydrogen, methane and water vapor). He thought these combined to form the more complex compounds found in living things.

Lazzaro Spallanzani - 1768

-tried a controlled experiment with broth -sterilized the broth by boiling it in flasks -one flash was sealed, the other was left open -Microrganismes formed in the uncovered flask - microorganisms did not come from the broth - were in the air that entered the flask -not even microorganisms came from nonliving things