SOME VIRUSES CAUSE CANCER.Certain types of cancers have been linked to cancer viruses. Burkitt's lymphoma, cervical cancer, liver cancer, T-cell leukemia and Kaposi sarcoma are examples of cancers that have been associated with different types of viral infections. The majority of viral infections however, do not cause cancer. SOME VIRUSES ARE NAKED.All viruses have a protein coating or capsid, but some viruses, such as the flu virus, have an additional membrane called an envelope. THERE ARE TWO CLASSES OF VIRUSES: DNA AND RNA VIRUSES. Viruses can contain single-stranded or double-stranded DNA as the basis for their genetic material, and some even contain single-stranded or double-stranded RNA. A VIRUS CAN REMAIN DORMANT IN A HOST FOR YEARS.Viruses undergo a life cycle with several phases. The virus first attaches to the host via specific proteins on the cell surface. Once attached, the virus then enters the cell by being engulfed or fusion. The host's mechanisms are used to replicate the DNA or RNA of the virus as well as essential proteins. After these new viruses mature, the host cell is killed to allow the new viruses to repeat the cycle. An additional phase before replication, known as the dormant phase, occurs in only a few viruses. During this phase, the virus can remain inside the host for long periods of time without causing any apparent changes in the host cell. HIV for example, can remain dormant for 10 years. VIRUSES INFECT PLANT, ANIMAL AND BACTERIAL CELLS.Viruses can infect bacterial and eukaryotic cells. The most commonly known eukaryotic viruses are animal viruses, but viruses can infect plants as well. These plant viruses usually need the help of insects or bacteria to get into a plant's cell wall. Once the plant is infected, the virus can cause several diseases which usually do not kill the plant but cause deformation in the plant's growth and development. A virus that infects bacteria is known as a bacteriophages or phage. Bacteriophages follow the same life cycle as eukaryotic viruses and can cause diseases in bacteria as well as kill them through lysis. In fact, these viruses replicate so well that entire colonies of bacteria can be destroyed quickly. Bacteriophages have been used in diagnosis and treatments of infections from bacteria such as E. coli and Salmonella. SOME VIRUSES USE HUMAN PROTEINS TO INFECT CELLS. HIV and ebola are examples of viruses that use human proteins to infect cells. The viral capsid contains both viral proteins and proteins from the cell membranes of human cells. The human proteins help to 'disguise' the virus from the immune system. RETROVIRUSES ARE USED IN CLONING AND GENE THERAPY.A retrovirus is a type of virus that contains RNA and that replicates its genome using an enzyme known as a reverse transcriptase. Retroviruses have the unique ability to insert genes into human chromosomes. These special viruses have been used as important tools in scientific discovery. Scientists have patterned many techniques after retroviruses including cloning, sequencing, and some gene therapy approaches. have a great weekend! Peace out!
12 Comments
Meirah
5/13/2017 09:36:14 am
AHHHHH!!!!! I'M SOOOOO SCARED!!!!!!
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Zane
5/13/2017 09:50:12 pm
Dats cool
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brady
5/14/2017 12:17:20 pm
EBOLA!? I did not sign up for this
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Meirah
5/14/2017 02:18:05 pm
HAHAHAHAHAHA!!!!!!
Reply
Zane
5/14/2017 11:49:03 pm
Bruh?
Reply
Zane
5/14/2017 11:49:47 pm
DATS SO COOL BUT WEIRD.
Reply
Haley
5/15/2017 07:27:06 am
That is interesting.
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Zaya
5/15/2017 07:29:03 am
That's honestly so scary how some viruses cause cancer
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Tabitha
5/15/2017 07:29:15 am
Hmmm I think retroviruses are cool.well kind of
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Katelyn Ashton
5/15/2017 07:39:18 am
Some some viruses look like snakes. It's like are bodies have traitors.
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Zaya
5/15/2017 07:42:43 am
The retrovirus and virus picture is so funny!
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Stephanie
5/15/2017 07:44:08 am
The Ebola virus is cool... the picture... it's very detailed
Reply
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Mrs. TaylorI love science! Everything about the world is interesting and never boring. I love to study plants, animals, insects, and people. My favorite subjects are my students who are the most unique organisms on the planet! Categories |