Viruses and Bacteria - Teacher - Free Printable

The image you've uploaded is a diagram illustrating the Lytic Cycle of a bacteriophage (a virus that infects bacteria). The task appears to be understanding and explaining this biological process.

Let's break down the solution step-by-step by analyzing the diagram.

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Step 1: Identify the components and stages in the diagram

The diagram shows a circular flow with five numbered steps, starting with a bacteriophage attaching to a bacterial cell and ending with the release of new phages. The key components labeled are:
- Bacteriophage: The virus.
- Bacterial chromosome: The genetic material of the host bacterium.
- Bacterial host cell: The cell being infected.
- Nucleic acid: The genetic material (DNA or RNA) of the bacteriophage.

The five stages are:
1. Attachment
2. Entry
3. Replication
4. Assembly
5. Lysis and Release

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Step 2: Explain each stage of the Lytic Cycle

I will now explain each step based on the visual information and general biological knowledge.

#### Stage 1: Attachment
The bacteriophage attaches to the surface of the bacterial host cell using its tail fibers. This is a specific interaction between viral proteins and receptors on the bacterial cell wall.

#### Stage 2: Entry
The bacteriophage injects its nucleic acid (genetic material) into the bacterial cell. The protein coat (capsid) of the phage remains outside the cell.

#### Stage 3: Replication
Once inside, the phage’s nucleic acid takes over the bacterial cell’s machinery. The bacterial DNA is often degraded, and the cell begins to produce new phage DNA and proteins instead of its own.

#### Stage 4: Assembly
Newly synthesized phage components (DNA and capsid proteins) are assembled into complete, mature bacteriophages within the bacterial cell.

#### Stage 5: Lysis and Release
The bacterial cell bursts open (lyses), releasing the newly formed bacteriophages. These can then go on to infect other bacterial cells, repeating the cycle.

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Step 3: Summarize the purpose and outcome

The lytic cycle is a method by which bacteriophages replicate and spread. It results in the destruction (lysis) of the host bacterial cell, hence the name “lytic.” This cycle is rapid and leads to the death of the host cell.

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✔ Final Answer:

The image illustrates the Lytic Cycle of a bacteriophage, which consists of five main stages:

1. Attachment: The bacteriophage binds to the surface of a bacterial cell.
2. Entry: The phage injects its nucleic acid into the bacterial cell.
3. Replication: The phage’s genetic material hijacks the bacterial machinery to replicate itself and produce new viral proteins.
4. Assembly: New bacteriophages are assembled from the replicated components.
5. Lysis and Release: The bacterial cell bursts, releasing the new phages to infect other cells.

This cycle ends with the destruction of the host cell and the propagation of the virus. It is a key mechanism in viral replication and is often used in research and medicine (e.g., phage therapy).

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Let me know if you’d like to dive deeper into any specific stage or component!