Our immune systems can only distinguish between the different types of H and N spikes they have been exposed to in the past.
There is little or no immunity in the human population to a new flu virus that can cause a global outbreak.
The H7N9 and H5N1 strains of flu virus have the potential to reach epidemic proportions.
The ability of these viruses to spread from birds to humans has led to severe illness and death.
Humans become infections because the H spikes can attach to both a bird flu and a human flu.
The virus has rarely been transmitted from one human to another, and close contact between domestic poultry and humans is necessary for this to happen.
Bird flu can be transmitted by coughing or sneezing, but it's rare at this time.
The new virus would be lethal in both cases.
Half of the people who get the H5N1 or H7N9 virus die, and there is no vaccine for it.
The H5N1 and H7N9 viruses have the same names.
The human upper respiratory tract could be affected by bird flu.
A combination of bird flu and human spikes could allow the virus to enter the human upper respiratory tract.
Between 2015 and 2016 Brazil experienced a dramatic increase in the number of babies born with microcephaly or abnormal smallness of the brain.
Health officials were investigating an outbreak of an illness that caused rash, inflammation, and pain.
Microcephaly, a condition in which babies are born with small heads, was caused by the Zika virus and researchers concluded that it could be passed from a mother to a fetus.
When a person is bitten by a mosquito, the virus can be passed on to new mosquitoes.
It can also be spread through sexual contact with an individual who has the disease.
Researchers were able to trace the genetic code of the virus in Brazil and conclude that it arrived in the country during a soccer tournament.
A mosquito extinction gene is being pursued as a permanent approach to prevention.
The solution may lie in the organisms that spread the disease.
The offspring will not survive if they mate with a female.
The population will decline eventually.
Within several months, small-scale trials have reduced populations by 80%.
Microcephaly is a condition caused by the spread of the mosquito-borne disease, and can be contracted from a pregnant mother to her infant.
The virus can jump to other species, including humans.
It is necessary to have a flu shot every year because the antibodies generated from last year's shot are not expected to be effective this year.
There are many different viruses that cause diseases in plants.
A number of diseases of crops, including potatoes, coconuts, and citrus, have been attributed to the fact that they are not viruses.
The cell can produce more viroids.
Prions are normally found in an animal but have a different structure.
Like viruses, prions can't replicate on their own but can cause infections by interacting with a normalprotein.
As simple as changing a chemical bond, the process of changing the structure of the normalprotein to the prion can be done.
Once a prion enters a body, a chain reaction begins that converts normal proteins to prions.
Small holes in the brain are created by clusters of prion proteins that break down normal brain tissue.
TSEs are fatal and untreatable.
Mad cow disease, or bovine spongiform encephalopathy, is a neurodegenerative disease of cattle that is transmissible to humans by eating cattle brains or meat contaminated with prion-infected brain tissue.
The discovery of prions began when it was observed that members of a primitive tribe in the highlands of the country died from a disease.
The cannibalistic practice of eating a dead person's brain caused the disease.
The lytic and lysogenic cycles of viral reproduction are compared.
Why is it beneficial to a virus if its host is dead?
bacteria and archaea are fully functioning, living, single-celled organisms.
The prokaryotes were not discovered until the 17th-century Dutch microscopist Antonie van Leeuwenhoek described them.
He believed that the "little animals" he observed could arise spontaneously.
When the meat was spoiled, it was thought that the flies came from it.
Scientists have conducted various experiments to determine the origin of organisms in laboratory cultures.
It showed that a previously sterile soup can't become cloudy with microorganism growth if it's exposed to the air.
Pasteur performed these types of experiments to disprove the theory of Spontaneous generation of microbes.
Today, we know that there are lots ofbacteria in the air, water, and soil and that newbacteria arise from the division of existingbacteria.
We know a lot about the structure ofbacteria, how and where they live, where they get their nutrition, and how they coordinate their replication.
First, we will look at the general characteristics of prokaryotes, then we will look at the specific characteristics of domain Bacteria and domain Archaea.