Comparing viruses to cells

Anderson Abbott

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Lytic and lysogenic cycles

In the lytic cycle a virus attaches to a cell and inserts its DNA and takes over the cell. The cell then makes thousands and thousands of copies of the virus before exploding and releasing its contents. In the lysogenic cycle the virus enters its DNA into the cells genome. The cell replicates and the lyctic cycle continues from there. Bacteriophage use the lysogenic cycle and the HIV virus uses the lytic cycle.

Characteristics of life

First viruses are not living organisms because they have no cells. Secondly viruses can not reproduce to n their own. They need cells to reproduce. Thirdly viruses have no metabolism which means that they cannot obtain or use energy. Viruses cannot maintain homeostasis. Science they cannot reproduce they cannot provide hereditary. However viruses can grow and develop. Viruses also adapt and evolve an respond to the environment.


1. Describe the typical structure of a virus. What are viruses made of? What biomolecules make up proteins? The typical structure of a virus is DNA in the center surrounded by a capsid and a protein coat. There are proteins ,lipids and nuclaic acids.

2.How do viruses enter cells? viruses enter the cell through insertion. Insertion can happen in too cycles, the lyctic and the lysogenic cycle. In the lysogenic cycle DNA connects to the actual genome while in the lyric cycle the DNA takes over the nucleus.

3.Explain why the Ebola virus cannot infect a tobacco plant. The Ebola virus cannot infect a tobacco plant becuse viruses are cell specify which means they only infect a certain kind of cell.

4. Name five viruses and the type of cell they infect.

1. HIV- T-cells

2. Ebola- dendritic cells

3. Influenza- epithelial cells ( airway cells)

4. Bacteriophage- bacterial cells

5. Canine parvovirus- lymphocytes in canines.

5. You have been diagnosed with the flu. Explain why the doctor will not prescribe you antibiotics. Antibiotics strengthen viruses by increasing their immunity to the drug and making them more resistant.

6. How is it that a person can be infected by a virus such as HIV but not show symptoms. Since viruses have to replicate in vast amounts to be noticed you can be infected for weeks and not show symptoms since it takes time to produce so many viruses.