Question: What Is A Flu Virus In Biology?

Is the flu an RNA replicating virus?

Influenza A viruses contain a segmented negative-sense RNA genome, which is transcribed and replicated by the viral-RNA-dependent RNA polymerase (FluPolA) composed of PB1, PB2 and PA subunits3,4,5..

What are the two major types of influenza viruses?

Currently, there are two subtypes of influenza A viruses found circulating among human populations: influenza A (H1N1) and influenza A (H3N2).

What does h1 n1 mean?

In the spring of 2009, scientists recognized a particular strain of flu virus known as H1N1. This virus is a combination of viruses from pigs, birds and humans that causes disease in humans. During the 2009-10 flu season, H1N1 caused the respiratory infection in humans that was commonly referred to as swine flu.

Is influenza the same as H1N1?

H1N1 flu is a subtype of influenza A. Subtypes of influenza A are categorized based on two proteins on the surface of the virus, hemagglutinin (H) and neuraminidase (N). There are many H and N subtypes, and each one is numbered. All H and N flu subtypes are influenza A viruses.

Is Flu A or B worse?

Frequently asked questions about Influenza A and B Influenza type A and type B are similar, but type A is overall more prevalent, sometimes more severe, and can cause flu epidemics and pandemics.

What is a flu virus life cycle?

The influenza virus life cycle can be divided into the following stages: entry into the host cell; entry of vRNPs into the nucleus; transcription and replication of the viral genome; export of the vRNPs from the nucleus; and assembly and budding at the host cell plasma membrane.

Is H1N1 the same as Spanish flu?

The first human cases of Spanish flu appeared in spring of 1918 while the first reports of the swine illness were in the fall of that year. Some strains of swine flu, including the one that has emerged recently from Mexico, are known to belong to the same subtype — H1N1 — as the Spanish flu.

Do viruses have DNA?

Most viruses have either RNA or DNA as their genetic material. The nucleic acid may be single- or double-stranded. The entire infectious virus particle, called a virion, consists of the nucleic acid and an outer shell of protein. The simplest viruses contain only enough RNA or DNA to encode four proteins.

How is influenza caused?

What Causes the Flu? The flu is caused by influenza viruses that infect the nose, throat, and lungs. These viruses spread when people with flu cough, sneeze or talk, sending droplets with the virus into the air and potentially into the mouths or noses of people who are nearby.

How is influenza passed?

Person to Person People with flu can spread it to others up to about 6 feet away. Most experts think that flu viruses spread mainly by droplets made when people with flu cough, sneeze or talk. These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.

What does the influenza A virus look like?

The structure of the influenza virus (see Figure 1) is somewhat variable, but the virion particles are usually spherical or ovoid in shape and 80 to 120 nanometers in diameter. Sometimes filamentous forms of the virus occur as well, and are more common among some influenza strains than others.

Is the flu a retrovirus?

Influenza is an RNA virus that causes mild to severe respiratory symptoms in humans and other hosts.

What is the meaning of flu virus?

Influenza, also called flu or grippe, an acute viral infection of the upper or lower respiratory tract that is marked by fever, chills, and a generalized feeling of weakness and pain in the muscles, together with varying degrees of soreness in the head and abdomen.

Is the flu a protein?

As in all viruses, the genome of an influenza virus particle is encased in a capsid that consists of protein. The influenza A capsid (Figure 2) contains the antigenic glycoproteins hemagglutinin (HA) and neuraminidase (NA); several hundred molecules of each protein are needed to form the capsid.

What is the flu virus made up of?

Influenza virus has a rounded shape (although it can be elongated or irregularly shaped) and has a layer of spikes on the outside. There are two different kinds of spikes, each made of a different protein – one is the hemagglutinin (HA) protein and the other is the neuraminidase (NA) protein.

What is H and N in flu?

Among other things, influenza A viruses are fashionistas. They cover themselves in an array of accessories. But instead of wearing Dolce and Gabbana, influenza prefers “H & N,” aka hemagglutinin and neuraminidase. Hemagglutinin and neuraminidase are little protein spikes on the flu’s surface that help it invade cells.

What is the scientific name of the flu?

Influenza, commonly known as “the flu”, is an infectious disease caused by an influenza virus.

Is the flu virus DNA or RNA?

All influenza viruses consist of single-stranded RNA as opposed to dual-stranded DNA. The RNA genes of influenza viruses are made up of chains of nucleotides that are bonded together and coded by the letters A, C, G and U, which stand for adenine, cytosine, guanine, and uracil, respectively.

Whats the difference between Flu A and Flu B?

Unlike type A flu viruses, type B flu is found only in humans. Type B flu may cause a less severe reaction than type A flu virus, but occasionally, type B flu can still be extremely harmful. Influenza type B viruses are not classified by subtype and do not cause pandemics.

How does the flu infect a human host?

When the influenza virus infects a host cell its goal is to produce many copies of itself that go on to attack even more cells. A viral enzyme, called polymerase, is key to this process. It both copies the genetic material of the virus and steers the host cell machinery towards the synthesis of viral proteins.