Jenny Li


Animal Cell

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Plant Cell

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Viral Reproduction

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Lytic Cycle

The lytic cycle is the faster cycle and goes through five steps. First is attachment in which the virus latches onto the host cell. Second is entry, this is where the virus injects its genetic material into the host cell. Thirds is replication, the virus has now taken over the replication process and is using the host to reproduce its genetic material. Fourth is assembly where a new phage is put together. And finally, the phages are released and the cycle is repeated. One type of virus that goes through the lytic cycle is the influenza virus.

Lysogenic Cycle

The lysogenic cycle is the slower cycle and takes a few different steps, however, some steps are the same as the lytic cycle. First, the virus attaches itself to a cell. Second, the genetic material is injected into the cell. Third, the virus's genetic material is incorporated into the host cell's original DNA. Fourth, the host cell replicates the DNA inside, including the viral DNA. Next, the cell goes through mitosis and creates an identical cell which also contains viral DNA. Lastly, the lytic cycle will occur after the virus is ready to become active. A type of virus that goes through the lysogenic cycle is the HIV virus.

Characteristics of Life

  1. Cells: Viruses are not made up of cells, but are made up of nucleic acids and protein.
  2. Maintain homeostasis: Viruses do not have a way to maintain homeostasis.
  3. Contain DNA: Viruses do contain DNA or RNA which they inject into their host cells.
  4. Ability to reproduce: Viruses do not have the ability to reproduce on their own.
  5. Use energy: Since a virus cannot eat, it has no need or way to obtain energy.
  6. Respond to environment: They respond to their environment, which is how they attack cells in the first place.
  7. Evolve: Viruses evolve to have the abilities to attack host cells and transmit themselves from one organism to another.
  8. Growth and development: Viruses do not have the ability to grow and develop, only to reproduce through host cells.


  1. Describe the typical structure of a virus. What is a virus made of? What biomolecules would you find in a virus? The typical structure of a virus includes DNA or RNA that is surrounded by a capsid (protein coat), enzymes, and an envelope (lipid membrane). It is made of DNA or RNA and the two biomolecules that can be found in every virus are nucleic acids and proteins.
  2. Discuss the different ways viruses gain entry into a cell. Some viruses gain entry by attaching themselves to the cell membrane and injecting their DNA or RNA into the cell. Others will enter through endocytosis.
  3. Explain why the Ebola virus would not infect a tobacco plant. Because their surface markers are not designed to look like a tobacco plant.
  4. Name five viruses and the type of cell that they attack. Ebola: attacks liver cells, cells in the immune system, and cells that line the inside of blood vessels; Chicken Pox: attacks sensory nerve cells; Flu: attacks cells in the respiratory system; HIV Virus: attacks helper T cells; Rabies: attacks cells in the nervous system.
  5. You have been diagnosed with the flu, Explain why your doctor will not provide you with a prescription for antibiotics in order to cure your infection. Because antibiotics are only useful against bacteria.
  6. How is it that a person an be infected with a virus such as HIV and not exhibit symptoms? The virus could be going through the lysogenic cycle in which there is a phase where the the virus is not active.