Viruses are not considered living because they . a. are not made of cells b. lack cell nuclei c.

step 1 Here we have an image of a virus, specifically known as a bacteriophage. This bacteriophage is c

Viruses are not considered living because they . a. are not...

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Key Concepts

Criteria for Life

Living organisms are typically defined by a set of characteristics such as organization, metabolism, growth, reproduction, and response to stimuli. Viruses, while they have genetic material and can evolve, lack many of these traits, particularly independent metabolism and the ability to reproduce outside of a host cell, which leads to debates about whether they are truly 'alive.'

Cellular Structure

A fundamental aspect of life, as outlined by the cell theory, is that living beings are composed of cells, which serve as the basic unit of structure and function. Viruses, however, do not have cells; they consist only of a protein coat and genetic material, which means they lack the cellular components necessary for independent life functions.

Dependence on Host Cells for Reproduction

An essential characteristic of living organisms is the ability to reproduce independently, typically through cellular division. Viruses are unique because they must enter a host cell and hijack its machinery in order to replicate. This dependency on a host not only underscores their lack of independent reproductive capability but also fuels the debate on their classification as living entities.

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