It depends on which virus you are referring to specifically. Viruses come in many shapes and types; their variations are tremendous.
For HIV and Influenza, viruses acquire their envelops after maturation, during the budding off or detachment stage from the host cell.
Hope this helps! :)
<span>The three groups of amphibians: Frogs, Salamanders, Caecilians are different when they reach adulthood. Frogs have four legs with strong hind legs and no tails. Salamanders have tails and four short, weak legs that cause them to walk instead of jump. Lastly, Cacilians have no legs and are burrowing animals.
Amphibians must live in moist environments because they loose water through their thin skin. They need to be near water to replenish the lost water. Also their skin helps them breathe and they can get oxygen from the water.</span>
The study of distribution of living organism is kow as demography, while studying their fosils is known as paleantology.
