What is a coronavirus? - Elizabeth Cox
For almost a decade scientists based the source of a deadly new virus through Chinastatest moun tains and most isolated caverns. They finally found it here in the bats of Shitou Cave. The virus in Question was a coronavirus that caused an epidemic of severe acute respiratory syndrome or SARS.
in 2003. Coronaviruses are a group of viruses covered the protein spikes that look ike a crown- or corona in Latin. There are hundreds of known coronaviruses. Seven of them infect humans and can cause disease. The coronavirus SARS-CoV causes SARS. MERS-CoV causes MERS and SARS CoV-2 causes the disease COVID 19. O1 The seven human coronaviruses, four cause colds, mild, highly contagious infections of the nose and throat. Two infect the lungs. and cause much more severe inesses. The seventh which causes COVID-19. has features of each it spreads easily, but can severely impact the lungsWhen an Infected person coughs, droplets containing the virus spray out. The virus can infect a new person when the droplets enter their nose or mouth. Coronaviruses transmit best in enclosed spaces, where people are close together, Cold weather keeps their delicate casing from drying out enabling the virus to survive for longer between hosts, while UV exposure from sunlight may damage it. These seasonal variations matter more for established viruses. But because no one is yet immune
to a new virus, it has so many potential hosts that it doesn't need ideal conditions to spread In the body, the protein spikes embed in the host's cells and fuse with them- enabling the virus to hijack the host cells machinery to replicate its own genes. Coronaviruses store their genes on RNA. All viruses are either RNA viruses or DNA viruses, RNA viruses tend to be smaller, with fewer genes, meaning they infect many hosts and replicate quickly in those hosts, In general. RNA viruses don't have a proofreading mechanism. whereas DNA viruses do, So when an RNA virus replicates. It much more likely to have mistakes called mutations. Many of these mutations are useless or even harmful. But some make the virus better suited for certain environments - like a new host species. Epidemics often occur when a virus jumps from animals to humans. This is true of the RNA viruses that caused the Ebola, Zika, and SARS epidemics, and the COVID-19 pandemic Once In humans the virus still mutates- usually not enough to create a new virus. but enough to create variations. or strains of the original one. Coronaviruses have a few key differences from most RNA viruses They re some of the largest, meaning they have the most genes. That creates more opportunity for harmful mutations. To counteract this risk, coronaviruses have a unique feature: an enzyme that checks for replication errors and corrects mistakes This makes coronaviruses much more stable, with a slower mutation rate, than other RNA viruses While this may sound formidable, the slow mutation rate is actually a promising sign when it comes to
disarming them, After an infection, our immune systems can recognize germs and destroy them more
quickly it they infect us again so they don't make us sick But mutations can make a virus less recognizable
our immune systems-and therefore more difficult to fight off. They can also make antiviral drugs and vaccines iess effective, because they're tailored very specifically to a virus. That's why we need a new flu vaccine every year the influenza virus mutates so quickly new strains pop up constarity The slower mutation rate of coronaviruses means our immune systems drugs. and vaccines might be able to recognize them for longer after infection, and therefore protect un better. Still, we dont know how long our bodies remain immune to different coronaviruses. There's never been an approved treatment or vaccine for a coronavirus We have focused on treating the ones that cause colds and though scientists been developing treatments for SARS and MERS, the epidemics ended before those treatments completed clinical trials As we continue to encroach on other animals habitats some scientists say a new coronavirus jumping to humans is inevitable - but if we investigate these unknowns. it doesnt have to be desting
to
3 - A) Retorne ao texto e escrevaWhat is a coronavirus?escreva em quais parágrafos encontram-se os
seguintes pronomes relativos caso haja: who, where, that, which, ou when. *
Respostas
Resposta:
For almost a decade scientists based the source of a deadly new virus through Chinastatest moun tains and most isolated caverns. They finally found it here in the bats of Shitou Cave. The virus in Question was a coronavirus that caused an epidemic of severe acute respiratory syndrome or SARS.
in 2003. Coronaviruses are a group of viruses covered the protein spikes that look ike a crown- or corona in Latin. There are hundreds of known coronaviruses. Seven of them infect humans and can cause disease. The coronavirus SARS-CoV causes SARS. MERS-CoV causes MERS and SARS CoV-2 causes the disease COVID 19. O1 The seven human coronaviruses, four cause colds, mild, highly contagious infections of the nose and throat. Two infect the lungs. and cause much more severe inesses. The seventh which causes COVID-19. has features of each it spreads easily, but can severely impact the lungsWhen an Infected person coughs, droplets containing the virus spray out. The virus can infect a new person when the droplets enter their nose or mouth. Coronaviruses transmit best in enclosed spaces, where people are close together, Cold weather keeps their delicate casing from drying out enabling the virus to survive for longer between hosts, while UV exposure from sunlight may damage it. These seasonal variations matter more for established viruses. But because no one is yet immune
to a new virus, it has so many potential hosts that it doesn't need ideal conditions to spread In the body, the protein spikes embed in the host's cells and fuse with them- enabling the virus to hijack the host cells machinery to replicate its own genes. Coronaviruses store their genes on RNA. All viruses are either RNA viruses or DNA viruses, RNA viruses tend to be smaller, with fewer genes, meaning they infect many hosts and replicate quickly in those hosts, In general. RNA viruses don't have a proofreading mechanism. where as DNA viruses do, So when an RNA virus replicates. It much more likely to have mistakes called mutations. Many of these mutations are useless or even harmful. But some make the virus better suited for certain environments - like a new host species. Epidemics often occur when a virus jumps from animals to humans. This is true of the RNA viruses that caused the Ebola, Zika, and SARS epidemics, and the COVID-19 pandemic Once In humans the virus still mutates- usually not enough to create a new virus. but enough to create variations. or strains of the original one. Coronaviruses have a few key differences from most RNA viruses They re some of the largest, meaning they have the most genes. That creates more opportunity for harmful mutations. To counteract this risk, coronaviruses have a unique feature: an enzyme that checks for replication errors and corrects mistakes This makes coronaviruses much more stable, with a slower mutation rate, than other RNA viruses While this may sound formidable, the slow mutation rate is actually a promising sign when it comes to
disarming them, After an infection, our immune systems can recognize germs and destroy them more
quickly it they infect us again so they don't make us sick But mutations can make a virus less recognizable
our immune systems-and therefore more difficult to fight off. They can also make antiviral drugs and vaccines iess effective, because they're tailored very specifically to a virus. That's why we need a new flu vaccine every year the influenza virus mutates so quickly new strains pop up constarity The slower mutation rate of coronaviruses means our immune systems drugs. and vaccines might be able to recognize them for longer after infection, and therefore protect un better. Still, we dont know how long our bodies remain immune to different coronaviruses. There's never been an approved treatment or vaccine for a coronavirus We have focused on treating the ones that cause colds and though scientists been developing treatments for SARS and MERS, the epidemics ended before those treatments completed clinical trials As we continue to encroach on other animals habitats some scientists say a new coronavirus jumping to humans is inevitable - but if we investigate these unknowns. it doesnt have to be desting