What is meant by antigenic drift and antigenic shift?

What is meant by antigenic drift and antigenic shift?

Antigenic drift involves the accumulation of a series of minor genetic mutations. Antigenic shift involves “mixing” of genes from influenza viruses from different species. Pigs, birds, and humans.

What is the meaning of antigenic drift?

One way flu viruses change is called “antigenic drift.” Drift consists of small changes (or mutations) in the genes of influenza viruses that can lead to changes in the surface proteins of the virus, HA (hemagglutinin) and NA (neuraminidase).

What is an example of an antigenic drift?

The emergence of a new strain of influenza A due to antigenic drift can cause an influenza epidemic or pandemic. Antigenic drift is also known to occur in HIV (human immunodeficiency virus), which causes AIDS, and in certain rhinoviruses, which cause common colds in humans.

Is antigenic shift and antigenic drift same?

Antigenic drift vs. shift. Antigenic drift creates influenza viruses with slightly modified antigens, while antigenic shift generates viruses with entirely new antigens (shown in red). Source: Wikipedia Commons and USDA.

What is the difference between antigenic drift and antigenic shift quizlet?

Antigenic drift is the accumulation of small mutations which occurs slowly over time as a result of mistakes during replication – minor changes. Antigenic shift is a major change where whole segments of the genome are exchanged with a different flu virus in a process called genetic reassortment.

What happens during antigenic shift?

antigenic shift, genetic alteration occurring in an infectious agent that causes a dramatic change in a protein called an antigen, which stimulates the production of antibodies by the immune systems of humans and other animals.

What is antigenic drift or genetic drift )? What is antigenic shift or genetic shift )? Quizlet?

Antigenic drift is the accumulation of random mutations in the RNA genome that can cause minor changes in hemagglutinin antigen structures. This occurs annually and is the reason we must have a seasonal flu shot.

What happens during antigenic drift quizlet?

What causes antigenic drift?

20 Antigenic drift is caused by point mutations in the HA and NA genes that are driven by immune pressure and the infidelity inherent in the replication of RNA genomes.

Why does antigenic drift happen?

Antigenic drift: A subtle change in the surface glycoprotein (either hemagglutinin or neuraminidase) caused by a point mutation or deletion in the viral gene. This results in a new strain that requires yearly reformulation of the seasonal influenza vaccine.

What is antigenic drift antigenic shift during which of these events does a major pandemic occur?

Antigenic Shift This shift typically occurs when a human flu virus crosses with a flu virus that usually affects animals (such as birds or pigs). When the viruses mutate, they shift to create a new subtype that is different from any seen in humans before.

What is antigenic drift and antigenic shift quizlet?

antigenic drift. due to mutations. -minor change in amino acid composition in hemagglutinin or neuramindase. -results in decreased ability of the host cells to recognize them. -occurs among influenze A virus resulting in emergence of new variations of prevailing strains every year.

How is antigenic shift different from antigenic drift quizlet?

How is antigenic shift different from antigenic drift? The change in viral proteins is sudden. Genetic information is exchanged between different strains. A new viral strain is formed that represents a mix of two or more strains.

Where does antigenic shift occur?

Antigenic shift or reassortment variations occur only in influenza A viruses, which are sudden and complete changes in one or both surface antigens. This results completely in new viruses having surface antigens different from the antigens of the old viruses circulating in the population.

What is antigenic shift explain its ability to cause pandemics and how likely is this to occur?

Antigenic shift refers to the complete replacement of the HA or NA with a novel HA or NA. These viruses are “new” viruses to which the population has no specific immunity. When such a new virus is introduced into a population, a severe, worldwide epidemic, or pandemic, of influenza can result.

What is antigenic drift or genetic drift quizlet?

What does the antigenic shift cause quizlet?

Antigenic shift leads to the generation of a novel virus strain to which no one on Earth would be immune. It occurs when two strains of flu virus infect the same cell.

What is genetic shifting?

An abrupt transition in a genetically determined characteristic that is presumably due to a mutation. This happens with some pathogenic microorganisms, such as the influenza virus, and explains the origin of some antibiotic-resistant strains of pathogenic bacteria.

What is a real life example of genetic drift in nature?

The bottleneck effect is an extreme example of genetic drift that happens when the size of a population is severely reduced. Events like natural disasters (earthquakes, floods, fires) can decimate a population, killing most individuals and leaving behind a small, random assortment of survivors.