Within the section on Natural Sciences and its Technologies of the National High School Exam (Enem), there is the field of biology. This is the material responsible for unraveling the phenomena related to living organisms.
For this reason, it is possible that Enem is composed of questions that address the origin of life on Earth and its aspects, as well as the scientific processes that led scholars to create the main existing theories, such as abiogenesis, biogenesis, chemical evolution and panspermia.
To stay sharp and ready to tackle questions on these topics, follow this article from the Practical Study . This is because, in addition to explaining what these theories really are about, the text also brings examples of questions about the subjects covered in Enem and other entrance exams in Brazil.
Theories of the origin of life
There are at least four theories about the origin of life. Of these, two are very old and were the first to be elaborated by scholars, they are chemical evolution and panspemia. In the case of the first, the hypothesis was that life arises from the mixture of inorganic components that were transformed into organic ones.
Regarding panspemia, the theories are totally different, since in this situation the defenders believe that life occurs through the joining of several molecules from celestial bodies, such as comets.
The best known, however, are abiogenesis and biogenesis. One is the contradiction of the other, the last being the true theory of how life on the Planet arises. In the case of abiogenesis, it was believed that life originated from a spontaneous generation. According to supporters of this hypothesis, from the garbage a mouse could appear or from a spoiled food flies could be born.
In opposition to these ideas, Francesco Redi, Spallanzani and Louis Pasteur, elaborated the biogenesis. All three scientists worked at different times, but the results of their research contradict abiogenesis, given that life can only exist through another pre-existing one.
To explain the theory, scientists used pieces of meat in glass, where one was covered and one was not. Over the days, the uncovered container contained larvae and the other did not. As a result, it was observed that the larvae only appeared due to the action of the flies. This is the theory accepted to this day as the most correct.
Questions about the origin of life
01) (UFMG / 2005) Observe this figure:
IT IS CORRECT to state that the presence of caterpillars on corn cobs is due
to a) the spontaneous generation process common to invertebrates.
b) the transformation of grains into caterpillars.
c) the development of eggs deposited by butterflies.
d) rotting of the cob and grains.
2) (QUESTION OF ENEM 2012) In certain places, fly larvae, raised on cooked rice, are used as bait for fishing. Some breeders, however, believe that these larvae arise spontaneously from cooked rice, as advocated by the theory of spontaneous generation.
This theory began to be refuted by scientists in the 17th century, based on the studies by Redi and Pasteur, who showed experimentally that
a) living beings can be created in the laboratory.
b) life originated on the planet from microorganisms.
c) the living being comes from the reproduction of another pre-existing living being.
d) wormlike beings and microorganisms are evolutionarily related.
e) worms and microorganisms are generated by the matter existing in the corpses and in the nutrient broths, respectively.
3) (PUC-MG) In one experiment, Francesco Redi placed a piece of meat in eight glass jars. Its opening was covered with four pieces of gauze. After a few days, fly larvae appeared on the glasses that did not contain the gauze covering the opening of the bottle. In the gauze-protected bottles, they did not appear.
This experience illustrates the principle of:
a) Cellular Theory.
c) ecological succession.
d) cell origin.