2007-02-15 11:44:04 · 5 answers · asked by quadravis m 1 in Science & Mathematics ➔ Biology
Because (a) they do not metabolize (convert energy); and (b) they do not self-replicate (they require the reproduction machinery of living cells to replicate them).
A virus is basically a piece of DNA or RNA wrapped in a protein coat to protect it.
2007-02-15 13:09:03 · answer #1 · answered by secretsauce 7 · 0⤊ 0⤋
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2016-08-21 13:12:10 · answer #2 · answered by ? 3 · 0⤊ 0⤋
Biologists debate whether or not viruses are living organisms. Some consider them non-living as they do not meet all the criteria used in the common definitions of life. For example, unlike most organisms, viruses do not have cells. However, viruses have genes and evolve by natural selection. Virus do not meet two essential criteria to be considered as living - 1. All living thing reproduce while virus replicates 2. All living thing grows with time, virus do not grow they just replicate by using host genetic mechanism
2016-05-24 04:59:51 · answer #3 · answered by Anonymous · 0⤊ 0⤋
They must use other cells to multiply. A virus is dormant until it enters a cell and takes over the cell processes to reproduce. Once it is free of the cell the virus must invade another or remain dormant.
2007-02-15 11:48:58 · answer #4 · answered by physandchemteach 7 · 1⤊ 0⤋
One of the characteristics of living things is that they are made of at least one cell. Viruses are not made of cells.
2007-02-15 11:53:22 · answer #5 · answered by Cathy K 4 · 1⤊ 0⤋