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:
A
Explanation:
Enzymes work best within specific temperature and pH ranges, and sub-optimal conditions can cause an enzyme to lose its ability to bind to a substrate. However, extreme high temperatures can cause an enzyme to lose its shape (denature) and stop working.
C: Photosphere ,corona ,chromosphere.
Answer:
A, G2.
Explanation:
G2, the second gap, occurs directly after S phase, the synthesis of new DNA.
Answer: Food storage
Explanation:
Stomach is a small pouch like structure which has the ability to store food temporarily.The storage of the food temporarily takes place in the stomach. The food that we eat reaches to the stomach by the help of food pipe.
Here, the food is stored until it is completely broken down into simpler form and enzymes act on them.
The food is then absorbed in the small intestine. But before this food is temporarily stored in the stomach where all the digestive juices and enzymes come to act on the food.
