Question

Which of the followings cannot be used to culture viruses? a. tissue culture b. liquid medium only c. embryo d. animal host

Short answer

b. liquid medium only

Step-by-step solution

Understand what is required

The question asks which option cannot be used to culture viruses. The goal is to identify the option that does not provide a suitable environment for viral growth.

Evaluate each option individually

Consider each option and its suitability for culturing viruses.

Step 2.1: Evaluate tissue culture

Tissue culture involves growing cells in a controlled artificial environment. Viruses can infect these cells, making tissue culture a suitable method for virus cultivation.

Step 2.2: Evaluate liquid medium only

Viruses require host cells to replicate. A liquid medium alone does not provide the necessary cellular machinery for viral replication, making it unsuitable for culturing viruses.

Step 2.3: Evaluate embryo

An embryo has living cells that viruses can infect and replicate within. Hence, it is a suitable method for virus cultivation.

Step 2.4: Evaluate animal host

An animal host provides a complete living system in which viruses can infect and replicate in the cells, making it a suitable method for virus growth.

Determine the unsuitable option

After evaluating all the options, it is clear that a liquid medium only cannot be used to culture viruses because it does not provide host cells necessary for viral replication.

Key concepts

Tissue Culture

Tissue culture is a method used to grow cells in a controlled, artificial environment. This technique is versatile and allows for the cultivation of a wide range of cell types. When it comes to viruses, tissue culture provides the necessary living cells that viruses need to infect and multiply. In this method, cells are usually grown in special containers filled with nutrient-rich media. Viruses are then introduced to these cells, infecting them and using the cells' machinery to replicate. This makes tissue culture a powerful tool for studying viral behavior, vaccine production, and drug testing. Advantages of tissue culture include its scalability, control over the growth environment, and the ability to use human or animal cells, making it highly relevant for medical research.

Viral Replication

Viral replication is the process by which viruses produce more copies of themselves within a host cell. Unlike bacteria, viruses cannot replicate on their own and require the cellular machinery of a living organism. The process typically involves several stages: attachment, entry, replication of viral genome, assembly of new viral particles, and release. Initially, the virus attaches to a specific receptor on the surface of a host cell. Once inside, it hijacks the host's cellular machinery to produce viral components. These components are then assembled into new virus particles, which are released either by bursting the host cell (lysis) or budding off from the cell membrane, to infect new cells. Understanding viral replication is crucial for developing antiviral drugs and vaccines.

Host Cells

Host cells are the living cells that viruses infect in order to replicate. Different viruses target different types of cells, depending on the presence of specific receptors. For instance, the human immunodeficiency virus (HIV) targets CD4+ T cells, which are a type of immune cell. Once a virus finds a suitable host cell, it attaches to the cell surface and enters the cell. Inside the host cell, the virus manipulates the cell’s machinery to produce more virus particles. Without host cells, viruses cannot replicate or survive, which is why methods of virus cultivation often involve living cells, such as in tissue culture or animal hosts.

Virus Culture Techniques

Virus culture techniques involve methods used to grow and study viruses in a laboratory setting. The major techniques include tissue culture, embryonated eggs, and the use of live animal hosts.

• Tissue Culture: Growing cells in flasks or plates to provide a medium for viral infection.
• Embryonated Eggs: Often used for flu viruses, where the virus is injected into the egg, allowing it to replicate in the developing tissues of the embryo.
• Live Animal Hosts: Using live animals to study virus behavior in a complex living system.

Each method has its advantages and drawbacks, and the choice of technique depends on the specific requirements of the study or application. Tissue culture is commonly used due to its control and scalability, while embryonated eggs are valuable for vaccine production. Animal hosts can provide comprehensive insights into viral behavior in a whole organism.