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Test: ACT Science
Before modern technologies and experiments allowed scientists to understand different organisms' mechanisms of reproduction, numerous theories existed about how populations came to exist. Two scientists from the 1800s describe their theories. Here are their arguments.
Scientist I
Just like some plants come from seeds and others are capable of vegetative (asexual) reproduction, some animal organisms come from non-sexual reproduction as well. Maggots, for example, appear on rotting carcasses. It is clearly illogical to suggest that the dead animal created or gave birth to the maggots, as it is no longer alive and is therefore incapable of sexual reproduction. The only rational conclusion for the appearance of maggots is a spontaneous generation. This is similar to how, if one were to leave a bowl of broth in the open air for a week, it would turn cloudy from bacteria appearing in the liquid.
Scientist II
Animate objects cannot arise from inanimate objects. Even when plants perform asexual reproduction, daughter plants are still coming from parent plants. There is no other example in nature of a living organism spontaneously coming into being. It is true that we observe maggots on rotting carcasses, but that does not necessarily mean that the maggots came from the rotting carcass. Similarly, bacteria growing in broth do not necessarily come directly from the broth. If a living organism appears, then it must have come from another animate object, even if we did not witness it. It is more likely that these invisible organisms have come in through the air and we simply do not see them until they have had a chance to replicate in these locations.
| 27. | Which of the following experiments might a third scientist perform to see which of these two theories is correct? |
Leave the refrigerator open indefinitely and observe the molds that appear
Leave a piece of meat unattended for several days, then return and observe
Leave broth under a heatlamp to observe if temperature affects bacterial growth
Seal off a liter of broth so that no air can get in, then observe the changes when the seal is broken and air can enter
