CHARACTERISTICS OF VIRUSES

VIRUS

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From the Latin word meaning "poison“Pathogen: infectious agent causing disease

Ebola Virus

VIRUS STRUCTURE

Viruses are tiny!Virus: 20 - 500 nmBacteria: 200 - 2000 nmHuman Cells: 5000 – 100000 nm

VIRUS STRUCTURE Viruses are acellular Not a cell as it has no nucleus, cytoplasm or organelles

Viruses consist of two main parts:1. Nucleic Acid – DNA or RNA found at the

core of the virus2. Capsid – Protein coat surrounding the

genetic materialSome viruses have an outer envelope made of lipids (fats) and proteins covering the capsid

VIRUS SHAPE Viruses come in a variety of shapes: Rod Spherical Irregular or Tadpole

LIVING CHARACTERISTICS OF VIRUSES

Contains genetic materialAble to reproduce (within host cell only)Able to invade host cell and reprogram cellular machineryCauses an infectious diseaseAble to mutate

NON-LIVING CHARACTERISTICS OF VIRUSES No metabolic needs – Doesn’t eat, breathe, sleep, produce wastes

etc.Not made of cellsAble to crystalize and remain dormant

Because viruses contain both living and non-living characteristics they are considered to be transitional between life and non-life