Question

2. Viruses are not considered living and a uses are not considered living and are therefore not found in the Linnaean system of taxonomy. Why are viruses not considered to be living? (page 3 In your answer * Explain the structure of a virus and how they are different from a living cell wn needs to maintain organelles through the use of ATP, water and oxygen (1) • explain how viruses use living cells to reproduce themselves (1)

Answer 1

Viruses are not considered living as it unable to replicate without the help of host machinery. Viruses do not exhibit any sign of life such as replicate, movement, growth, etc; when it is present in an environment without association with a host cell.

Structures of viruses are very simple. It contains protein and nucleic acid. Viruses do not contain any organelles which require sustaining life independently, such as mitochondria, endoplasmic reticulum, Golgi complex, ribosome, etc.

Viruses enter into the host cell (human or any other organisms) either in a receptor-dependent or independent manner. Upon entry into host cells, viruses hijack the host machinery to direct the cellular processes which favor viral replication and protein synthesis. Viruses modulate the function of eIF (eukaryotic elongation factor) which support the viral protein synthesis. Eukaryotic organisms also have the immune system which protects us from infection. Viruses inhibit and evade immune system to establish the useful infection and hence replication. After completing life cycle, viruses modulate the plasma membrane to release its progeny into the extracellular matrix that infect new cells.