Lightning or two wires touching each other
The answer is 'Cambrian' explosion. This took place approximately 541 million years ago. 'Explosion' refers to the evolution of a large range of new major animal phyla. Scientists know this by the large number of diverse fossils from this period. Prior to this period, organisms were single-celled, but over the Cambrian Explosion, lasting about 80 million years, life forms diversified rapidly to resemble the life forms existing today.
I believe the correct answer would be C. Sartorius i believe this is the answer, after doing some research on gO0gLe.
Answer:
Because they can only reproduce in a living cell
Explanation:
Virus is an organism that is incapable of replicating on its own without a living host. A virus infects a living host and makes use of Its replicational ability to produce new virions. A virus consists of a genetic material surrounded by a Protein called CAPSID. It does not possess the characteristics of other living organisms.
This means that it does not carry out any of the features a living cell undergoes e.g reproduction, respiration etc. Due to this reason, it is not classified as a living thing. They don't possess organnelles that carry out this peculiar functions.
A virus is considered a peculiar microorganism because it can only live and reproduce in a living host cell.
Pines, spruces, and firs are conifers