8
votes
1answer
1k views

How long does the Ebola virus remain infectious on contaminated items or surfaces?

I'm sure there will be variation depending on what the contaminated item or surface is made of - linens, I could imagine, would remain dangerous for longer than a door-knob. But if the items are not ...
10
votes
2answers
169 views

Why don't we develop immunity against common cold?

We all suffer from common cold, and that, frequently. Why have we not developed immunity against it till now? By immunity I mean immunity as a species.
0
votes
0answers
11 views

What is the role of antigens of HBV in development of disease?

What is the role of different forms (filamentous and spherical) of HBV? Both forms are made exclusively of HBsAg. The filamentous form contains just much more (200 nm length), while 20 nm length for ...
2
votes
1answer
43 views

How does the MMR vaccine affect lymph nodes in preventing measles?

I am trying to understand this statement about the Measles part of the MMR (Mumps, Measles and Rubella) vaccine Measles prevention: MMR (AB protect during primary and secondary viremia) Measles ...
14
votes
1answer
1k views

What do viruses do during incubation period?

For example, there is an incubation period of around 1 to 3 days for common cold, and that of AIDS can range over to decades. What do viruses do actually do during the incubation period? What ...
5
votes
2answers
71 views

Viruses: Adaptation to a new host through repeated host jumps

A friend told me, during a 3 minute discussion, that viruses that are endemic in host $A$ and make repeated jumps to host $B$ but can't be transmitted between individuals of species $B$, may slowly ...
1
vote
1answer
131 views

Is it impossible for a retrovirus to be lysogenic?

Is it impossible for retroviruses to be lysogenic? In the lysogenic cycle, the viral genetic material is incorporated into the host cell's DNA. Because retroviruses have RNA, it would be impossible ...
1
vote
1answer
31 views

In the lysogenic cycle, does the provirus split from the cell's main genetic material for replication?

In a diagram of the lysogenic cycle sent by my instructor in a video, it shows the provirus splitting from the cell's main DNA when the dormancy period ends and the viral DNA is "activated". Is this ...
3
votes
2answers
129 views

What happen's to a virus's capsid after it injects its genetic material into the host cell?

After a virus (one of the varieties which infects the cell via injection and not endocytosis) injects its genetic material into the host cell, what happens to its protein coat? I would guess that it ...
1
vote
1answer
48 views

Do lysogenic viruses only infect bacteria?

In the video sent by my teacher on viruses, the example he used for lysogenic viruses was a bacteriophage infecting a bacteria. When he was describing how the genetic material was incorporated into ...
2
votes
1answer
50 views

Lytic Viruses — Cell lysis?

So in the video my instructor sent on viruses, he said that for lytic viruses, new viruses manufactured by the host cell could get out of the cell in one of two ways. The new viruses would leave by ...
3
votes
2answers
87 views

Are viruses self-propelled?

So obviously, viruses are nonliving. But when my teacher was teaching viruses in the video (we're doing "flip" learning this semester), the way he described it, it seemed like the viruses responded to ...
16
votes
6answers
2k views

Why isn't a virus “alive”?

The recent news about a new supermassive virus being discovered got me thinking. What biological differences between viruses and cellular organisms have made viruses be deemed non-living?