If one defines life as the simplest form capable of displaying the most essential attributes of a living thing, one very quickly realizes that the only real criterion for life is the ability to replicate. Only systems that contain nucleic acids are capable of this phenomenon. This sort of reasoning has led to a new definition of organism:

Question

An organism is the unit element of a continuous lineage with an individual evolutionary history.

Consider the new definition of life. If you were to argue that a virus or a single mitochondria were, in fact, alive based on this definition, you would be ignoring the main tenet of
Responses
A cell theory.cell theory.
B endosymbiosis.endosymbiosis.
C nucleosynthesis.nucleosynthesis.
D natural selection.

Answer 1

To determine which option you would be ignoring when considering a virus or a single mitochondrion as alive based on the given definition of life, we should analyze the provided definition: "An organism is the unit element of a continuous lineage with an individual evolutionary history."

• Viruses do not have a cellular structure and cannot replicate independently; they rely on a host cell to reproduce. This absence of independent replication challenges their status as living organisms, especially considering the emphasis on the ability to replicate within the definition.

• Mitochondria are organelles that once existed as free-living prokaryotes and are often regarded as endosymbionts in the cell theory. While they possess their own DNA and can replicate independently within a cell, they do not exist as independent entities outside of the cell.

Given this understanding, both viruses and mitochondria challenge the idea of being considered organisms in the context of the definition you've provided. However, the definition emphasizes an "individual evolutionary history," which is more aligned with the notions outlined in cell theory.

Therefore, if you were to argue that a virus or a single mitochondrion is alive based on this definition, you would be ignoring the main tenet of:

A. cell theory.

Cell theory stipulates that all living organisms are composed of cells, and since viruses are acellular and mitochondria are not independent of the cells they reside in, both would not satisfy the key criteria laid out by cell theory.