Gen Bio 1; Francesco Redi and Spontaneous Generation - Group 3 Presentation.pptx

General Biology 1
Senior High School (STEM)

1. Spontaneous generation GROUP 3 FRANCESCO REDI AND

2. FRANCESCO REDI An Italian naturalist, physician, and poet. Besides Galileo, he was one of the most important scientists who challenged Aristotle 's traditional study of science. Redi gained fame for his controlled experiments. One set of experiments refuted the popular notion of Spontaneous Generation. Redi has been called the "Father of Modern Parasitology" and the "Founder of Experimental Biology".

3. REDI’S EXPERIMENT 01

4. REDI'S PROBLEM/ QUESTION A Where do flies come from? Is the rotting meat transformed into the flies? According to the records of early science, for centuries, people blindly believed in their interpretations of what they saw around them. Around 2000 years ago, they all assumed a spontaneous generation. Because Redi observed that flies and then maggots could be seen around pieces of meat that were left out in the open, he questioned it and did his own experiment.

5. The doctrine of spontaneous generation was coherently synthesized by Aristotle, who compiled and expanded the work of earlier natural philosophers and the various ancient explanations for the appearance of organisms. Spontaneous generation is a superseded scientific theory that held that living creatures could arise from nonliving matter and that such processes were commonplace and regular. It was hypothesized that certain forms, such as fleas, could arise from inanimate matter such as dust, or that maggots could arise from dead flesh. SPONTANEOUS GENERATION

6. REDI’S HYPOTHESIS B “only flies can make flies, and that rotting meat cannot be transformed into flies.“. As late as the 17th century, some biologists thought that some simpler forms of life were generated by spontaneous generation from inanimate matter. Many scientists opposed the theory and conducted many experiments to prove how living things arise, and the origin of life on earth. From that hypothesis, Redi conducted his experiment.

7. Having that thought in mind, he experimented using control groups and applied the scientific method to test his hypothesis. REDI’S PREDICTION C “if meat could not be transformed into flies, then the sealed containers should not produce either maggots or flies. Whereas if the meat can be so transformed, then the sealed jar should also develop maggots and flies,“

8. MODEL SYSTEM REDI USED Biogenesis refers to the process wherein life arises from similar life forms. This also gave rise to the cell, cell theory and the theories on the origin of life. Because Redi wanted to disprove the theory of spontaneous generation, he used the model system opposite of it. D BIOGENESIS

9. In science, a model is a representation of an idea, an object or even a process or a system that is used to describe and explain phenomena that cannot be experienced directly. Models are central to what scientists do, both in their research as well as when communicating their explanations. MODEL SYSTEM

10. REDI'S CONCLUSION E “maggots came from living flies, not from rotting meat or from dead flies or maggots.“ In 1668, Redi set up a series of flasks containing different meats, half of the flasks sealed, half open. He then repeated the experiment but, instead of sealing the flasks, covered half of them with gauze so that air could enter. Although the meat in all of the flasks putrefied, he found that only in the open and uncovered flasks, which flies had entered freely, did the meat contain maggots.

11. GROUP 3 EXPERIMENT 02

12. Texture, Odor, Presence of other living organisms, etc. OBSERVATI0NS

13. 15 MINUTES A C B

14. 1 HOUR A C B

15. 6 HOURS A C B

16. 20 HOURS A C B

17. 24 HOURS A C B

18. 4 DAYS A C B

19. CHANGES OBSERVED

20. AGREE OR DISAGREE 03

21. AGREE FRANCISCO REDI’S EXPERIMENT OUR EXPERIMENT Maggots swarmed on fresh meat in open containers, causing flies to hatch into flies. To prevent maggots from entering, Redi covered the jars with porous gauze layers. Flies were attracted to the smell of the rotting meat- which swarmed with maggots, but the meat itself remained free of maggots. When the jars were tightly covered so that flies could not get in, no maggots were produced. This suggests that flies are necessary for flies to produce themselves, not spontaneously from rotting meat. Three fresh meat were put simultaneosly in 3 different containers: one left open, one covered with one layer of gauze, and one tightly sealed. After several days of observation, the 3 decaying meat had different results. The unsealed container collected lots of maggots on the meat, which are the eggs of flies; the container covered with gauze had maggots but only on top and not on the meat; while the tightly covered container had developed no maggots. It explains that the Spontaneous Generation is not true and living things come from living matter.

22. CONCLUSION AND FINDINGS 04

23. The presence of maggots on the meat is not because of the abiotic matter (meat), but it came from the flies going into the specimen. CONCLUSIONS The Theory of Spontaneous Generation is wrong. All living things come from living matter: Biogenesis.

24. THANK YOU! Any questions?