What are viruses? Viruses are too small to be seen by the naked - TopicsExpress

What are viruses? Viruses are too small to be seen by the naked eye. They cant multiply on their own, so they have to invade a host cell and take over its machinery in order to be able to make more virus particles. Viruses consist of genetic materials (DNA or RNA) surrounded by a protective coat of protein. They are capable of latching onto cells and getting inside them. The cells of the mucous membranes, such as those lining the respiratory passages that we breathe through, are particularly open to virus attacks because they are not covered by protective skin. Most of us at one time or another have had colds or the flu, and we are especially vulnerable during the cold and flu season. The symptoms -- fever, congestion, coughing, sore throat -- spread through offices, schools and homes, no matter where in the world we live. Colds and flu (influenza) are caused by viruses. Viruses are responsible for many other serious, often deadly, diseases including acquired immunodeficiency syndrome (AIDS), Ebola hemorrhagic fever, infectious hepatitis and herpes. How can viruses cause so much trouble? What makes us so vulnerable to them, and what makes them spread? In this article, we will explore the world of viruses. Well talk about what a virus is, what viruses look like, how they infect us and how we can reduce the risk of infection. And youll learn why you feel so miserable when a cold virus attacks your body!If you have read How Cells Work, you know how both bacteria cells and the cells in your body work. A cell is a stand-alone living entity able to eat, grow and reproduce. Viruses are nothing like that. If you could look at a virus, you would see that a virus is a tiny particle. Virus particles are about one-millionth of an inch (17 to 300 nanometers) long. Viruses are about a thousand times smaller than bacteria, and bacteria are much smaller than most human cells. Viruses are so small that most cannot be seen with a light microscope, but must be observed with an electron microscope.

IF YOU DON`T THINK OBAMA HATES WHITES,THINK AGAIN.HIS CHOSEN

Okay we made it to Tucson AZ, we are staying at a RV park on Davis

Rubbermaid Commercial - Invader Side Gate Wet Mop Handles Wet Mop

The Saguenay Fjord’s wild beauty… Imagine yourself aboard a

Analysing recent developements first a reduction in subsidies

This is not the end, this is not the beginning Just a voice like

Teachers Day In many countries, Teachers Days are intended to

Dont think you need a lot of extra equipment for this. You are the

Lion of d Tribe of Judah, who fit put am 4 Zoo? Nobody! He broke

THE 7 WONDERS OF THE PARANORMAL WORLD: #2 MACHU PICCHU

There was seven brothers who married one woman.The first married

~ GOD Is Raining Blessings On You ~ Deuteronomy 28:12 (KJV)

YOU KNOW, GUYS, ITS SAD WHEN RELATIONSHIPS BREAK UP. YET, SOME ARE

’De quoi je me mêle’’ ? Une dépêche

#501 Ami ak jon er upor wholesale rag ugre debor aj. Uddishto

Buy New Dell Inspiron 15R (N5110) Laptop Lcd Front Bezel 15.6

Dark Tide Comics Hobby House will be showing the nightmare before

Pixie Dust Set of 20 ## Black Friday Cyber Monday Sales

Whatever you believe of yourself,e.g. spiritual, activist, new

Job Title: Organizational Capacity Development Coordinator