Eukaryotic cells, cells that contain membrane-bound organelles and generally reside within multicellular organisms, contain DNA, or deoxyribonucleic acid, which is organized into chromosomes. DNA is a double-stranded nucleic acid that forms a double helix. The bases found within a DNA molecule are adenine (A), thymine (T), guanine (G), and cytosine (C). DNA is organized into functional units, called genes, that encode the basic traits and characteristics of living organisms. DNA can be replicated within the nucleus prior to cell division to ensure each daughter cell receives an identical copy of DNA. The central dogma of molecular biology states that DNA is transcribed to RNA which is then translated into protein. RNA, or ribonucleic acid, is a nucleic acid found in all cells that serves a messenger to carry the genetic code from DNA to produce a functional molecule, the protein. RNA is a single-stranded nucleic acid and consists of the bases adenine (A), uracil (U), guanine (G), and cytosine (C). RNA is translated into amino acids on the ribosome to produce a polypeptide chain, or a protein. There are two general hypotheses for the original evolutionary molecule. The “RNA world” hypothesis states that the original genetic molecule is RNA, and RNA was able to be translated into protein and reverse transcribed to produce DNA. Alternatively, the “DNA, RNA, and Protein World” suggests that DNA was the original genetic molecule and was responsible for subsequent production of RNA and protein.

The central dogma of molecular biology supports which hypothesis?

Eukaryotic cells, cells that contain membrane-bound organelles and generally reside within multicellular organisms, contain DNA, or deoxyribonucleic acid, which is organized into chromosomes. DNA is a double-stranded nucleic acid that forms a double helix. The bases found within a DNA molecule are adenine (A), thymine (T), guanine (G), and cytosine (C). DNA is organized into functional units, called genes, that encode the basic traits and characteristics of living organisms. DNA can be replicated within the nucleus prior to cell division to ensure each daughter cell receives an identical copy of DNA. The central dogma of molecular biology states that DNA is transcribed to RNA which is then translated into protein. RNA, or ribonucleic acid, is a nucleic acid found in all cells that serves a messenger to carry the genetic code from DNA to produce a functional molecule, the protein. RNA is a single-stranded nucleic acid and consists of the bases adenine (A), uracil (U), guanine (G), and cytosine (C). RNA is translated into amino acids on the ribosome to produce a polypeptide chain, or a protein. There are two general hypotheses for the original evolutionary molecule. The “RNA world” hypothesis states that the original genetic molecule is RNA, and RNA was able to be translated into protein and reverse transcribed to produce DNA. Alternatively, the “DNA, RNA, and Protein World” suggests that DNA was the original genetic molecule and was responsible for subsequent production of RNA and protein.

A new organism is identified and the only nucleic acid contained within its cells is RNA. Which hypothesis would be supported by such a finding?

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.

Which of the following is a valid summary of Scientist II's argument against Scientist I?

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.

On which point do both scientists agree?

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.

An experiment is performed in which a bowl of broth containing bacteria is boiled and then left in the open air. After a day, the broth is observed to be cloudy. How might Scientist I explain this result?

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.

An experiment is performed in which a rotting carcass is vacuum sealed. After several weeks, no maggots are observed. The rotting carcass is removed from the vacuum seal, and several days later maggots are observed. Which theory does this best support?

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.

Fungal spores are placed on a slice of melon. After a certain amount of time, the only fungi that appear on the melon are the same species as the spores. What conclusion would Scientist II draw from this experiment?

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.

Why does Scientist I mention that some plants come from seeds, while some come from asexual reproduction?

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.

In order to create sourdough bread, the baker leaves the dough exposed. After a certain amount of time, the baker observes that the dough has begun to rise due to the addition of yeast. How would Scientist I explain this?

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.

If true, which of the following statements would disprove Scientist II's theory?