Question
Related Reading
Read about Francesco Redi’s famous experiment and how it disproved the theory of spontaneous generation. Record any observations that help you answer the Guiding Question.
1
What evidence did scientists use to reject the idea that animals like mice and eels come from nonliving things?
A
Examination of animal skeletons under a microscope
B
In-person observations of how these animals reproduce
C
Data on the number of eels and mice in a given space
D
Observations of how quickly these animals arrive in a new area
2
Match each term to its synonym.
Match answers from the answer bank with the items in the list. Use the arrow keys to select an answer and press space when you're ready to drag it to a new location. Then use the arrow keys to move the answer to a response area and press space to drop it.
Nonliving
Create
Living
Sudden
Animate
Generate
Inanimate
Spontaneous
3
Fill in the blanks to complete the sentences. Not all answer choices will be used.
Francesco Redi designed his experiment to see if
spontaneously generated from rotting
. He put meat into three jars: one left open, one covered in
, and one sealed. As the meat spoiled,
landed on the gauze
maggots appeared.
guaze
after
meat
flies
maggots
before
eels
4
How did the results of Redi's experiment disprove the theory of spontaneous generation?

Make an observation!
You will need strong observations to answer the Guiding Question later on.

The 1660s were an amazing time to be alive. Sure, the plague was going around and flushable toilets were few and far between, but the science was revolutionary! In fact, scientific work in this decade helped reshape the way we understand what it means to be alive.
By the mid-1600s, many scientists had rejected the idea that animals like mice and eels come from nonliving, or inanimate, objects. However, it was still believed that smaller, simpler organisms were born through spontaneous generation.
For example, maggots were thought to be “born” directly from rotting meat. Before microscopes were invented, the bodies and behavior of small organisms were difficult to observe. Because scientists couldn’t see the reproductive processes of organisms like maggots and flies, spontaneous generation seemed like the only explanation for their origin.
In 1668, Italian scientist Francesco Redi decided to test this hypothesis. To do this, he put fresh meat in three jars. He left one jar open, covered one in gauze (a thin fabric with very small holes), and sealed the final jar.

After a few days, there were flies and maggots on the meat in the open jar. However, there were no flies or maggots on the meat in the gauze-covered and sealed jars. What’s more, flies appeared on the gauze before maggots did. Maggots didn’t come from raw meat, they came from flies!
Redi’s work was more than a gross collection of rotten meat and maggots (though it probably did smell pretty bad). With the results of his experiment, Redi was able to reject the theory of spontaneous generation, famously concluding that “All life comes from life.”
Observation
0
Read about Francesco Redi’s famous experiment and how it disproved the theory of spontaneous generation. Record any observations that help you answer the Guiding Question.
1
What evidence did scientists use to reject the idea that animals like mice and eels come from nonliving things?
A
Examination of animal skeletons under a microscope
B
In-person observations of how these animals reproduce
C
Data on the number of eels and mice in a given space
D
Observations of how quickly these animals arrive in a new area
2
Match each term to its synonym.
Match answers from the answer bank with the items in the list. Use the arrow keys to select an answer and press space when you're ready to drag it to a new location. Then use the arrow keys to move the answer to a response area and press space to drop it.
Nonliving
Create
Living
Sudden
Animate
Generate
Inanimate
Spontaneous
3
Fill in the blanks to complete the sentences. Not all answer choices will be used.
Francesco Redi designed his experiment to see if
spontaneously generated from rotting
. He put meat into three jars: one left open, one covered in
, and one sealed. As the meat spoiled,
landed on the gauze
maggots appeared.
guaze
after
meat
flies
maggots
before
eels
4
How did the results of Redi's experiment disprove the theory of spontaneous generation?

Make an observation!
You will need strong observations to answer the Guiding Question later on.

The 1660s were an amazing time to be alive. Sure, the plague was going around and flushable toilets were few and far between, but the science was revolutionary! In fact, scientific work in this decade helped reshape the way we understand what it means to be alive.
By the mid-1600s, many scientists had rejected the idea that animals like mice and eels come from nonliving, or inanimate, objects. However, it was still believed that smaller, simpler organisms were born through spontaneous generation.
For example, maggots were thought to be “born” directly from rotting meat. Before microscopes were invented, the bodies and behavior of small organisms were difficult to observe. Because scientists couldn’t see the reproductive processes of organisms like maggots and flies, spontaneous generation seemed like the only explanation for their origin.
In 1668, Italian scientist Francesco Redi decided to test this hypothesis. To do this, he put fresh meat in three jars. He left one jar open, covered one in gauze (a thin fabric with very small holes), and sealed the final jar.

After a few days, there were flies and maggots on the meat in the open jar. However, there were no flies or maggots on the meat in the gauze-covered and sealed jars. What’s more, flies appeared on the gauze before maggots did. Maggots didn’t come from raw meat, they came from flies!
Redi’s work was more than a gross collection of rotten meat and maggots (though it probably did smell pretty bad). With the results of his experiment, Redi was able to reject the theory of spontaneous generation, famously concluding that “All life comes from life.”
Observation
0
Answers
GPT-4o mini
**1. What evidence did scientists use to reject the idea that animals like mice and eels come from nonliving things?**
**B. In-person observations of how these animals reproduce.**
---
**2. Match each term to its synonym.**
- Nonliving → Inanimate
- Create → Generate
- Living → Animate
- Sudden → Spontaneous
---
**3. Fill in the blanks to complete the sentences.** Not all answer choices will be used.
Francesco Redi designed his experiment to see if **maggots** spontaneously generated from rotting **meat**. He put meat into three jars: one left open, one covered in **gauze**, and one sealed. As the meat spoiled, **flies** landed on the gauze **before** maggots appeared.
---
**4. How did the results of Redi's experiment disprove the theory of spontaneous generation?**
The results of Redi's experiment disprove the theory of spontaneous generation by demonstrating that maggots do not arise directly from rotting meat. In his experiment, the open jar attracted flies, which laid eggs that turned into maggots, while the gauze-covered and sealed jars did not attract any flies or produce maggots. This indicated that life (in this case, maggots) came from another living organism (flies), thereby rejecting the notion that living organisms could spontaneously arise from nonliving matter. Redi conclusively showed that maggots are the offspring of flies, supporting the idea that "All life comes from life."
**B. In-person observations of how these animals reproduce.**
---
**2. Match each term to its synonym.**
- Nonliving → Inanimate
- Create → Generate
- Living → Animate
- Sudden → Spontaneous
---
**3. Fill in the blanks to complete the sentences.** Not all answer choices will be used.
Francesco Redi designed his experiment to see if **maggots** spontaneously generated from rotting **meat**. He put meat into three jars: one left open, one covered in **gauze**, and one sealed. As the meat spoiled, **flies** landed on the gauze **before** maggots appeared.
---
**4. How did the results of Redi's experiment disprove the theory of spontaneous generation?**
The results of Redi's experiment disprove the theory of spontaneous generation by demonstrating that maggots do not arise directly from rotting meat. In his experiment, the open jar attracted flies, which laid eggs that turned into maggots, while the gauze-covered and sealed jars did not attract any flies or produce maggots. This indicated that life (in this case, maggots) came from another living organism (flies), thereby rejecting the notion that living organisms could spontaneously arise from nonliving matter. Redi conclusively showed that maggots are the offspring of flies, supporting the idea that "All life comes from life."