Answer:
When the virus infects a cell, the RNA genome enters the cell and programs it to make new virus particles. These virus particles are released from the cell and go on to infect new cells. In humans, poliovirus is ingested, and replicates in cells of the gastrointestinal tract.Poliovirus, the prototypical picornavirus and causative agent of poliomyelitis, is a nonenveloped virus with a single-stranded RNA genome of positive polarity. The virion consists of an icosahedral protein shell, composed of four capsid proteins (VP1, VP2, VP3, and VP4), which encapsidates the RNA genome (1).RNA viruses generally have very high mutation rates compared to DNA viruses, because viral RNA polymerases lack the proofreading ability of DNA polymerases. The genetic diversity of RNA viruses is one reason why it is difficult to make effective vaccines against them.
Answer:
mitochondria
Explanation:
Mitochondria are organelles found in eukaryotic cells that are capable of generating the main part of the energy required for the cellular biochemical reactions. In addition, mitochondria are also involved in distinct biological functions including, among others, cell signaling, death, differentiation and growth. It is believed that mitochondria evolved from prokaryotic organisms which introduced inside others to form eukaryotic cells, this theory is known as the 'endosymbiotic theory'.
Finches adapt to the new conditions such as drought by changing the size, shape and depth of their beaks. Beak morphology varies according to drought conditions. Since after the drought, vegetation dries out and the hard, big, tough seeds remain, only the finches with deep beaks will survive. Finches adapt via their beaks to different foods sources and different local conditions.