Key Differences Between Plant and Animal Viruses Based on Structure Replication and Transmission
We are all aware of the pandemic caused by the coronavirus. It is not easy to kill viruses. Have you ever thought about why it is very difficult to destroy viruses? Viruses keep on changing their genetic material. That's why it is very difficult to make vaccines to kill viruses. To know more about plant and animal viruses and the difference between them, continue reading.
What is a Plant Virus?
Plant viruses are the viruses that infect plants and these are obligatory viruses that mean they can't replicate or reproduce without the host. As viruses do not have cellular machinery they use the machinery of plant cells to replicate and reproduce.
Structure of Plant Viruses
Viruses are made up of two components: proteins and genetic material. Protein subunits are placed around the circumference of the circle to form a disc. Then these discs are stacked around the genetic material of the virus and form a complete virus.
There are various shapes of plant viruses but most of the viruses are rod-shaped. And the length of these viruses is between 300-500nm. Isometric is the second most common shape of the plant virus. These types of viruses may have a double protein coat that is associated to form an icosahedral-shaped part. Very few plant viruses may have a lipid coat. The genetic material of plant viruses may be double or single-stranded DNA. But in most cases, single-stranded RNA is the genetic material of plant viruses.
Examples of Plant Viruses
An example of plant viruses that have double-stranded DNA as genetic material is the cauliflower mosaic virus. Bean golden mosaic virus is a plant virus that has single-strand DNA as genetic material. The tobacco mosaic virus is a plant virus that has single-stranded RNA as the material.
What is an Animal Virus?
The animal virus is a virus that infects animals and other viruses. This virus is also unable to replicate outside the animal body or animal cell. Animal viruses are also made of two components: protein and genetic material. The protein coat is known as capsid and genetic material is present inside it. Animal viruses also have an envelope made of lipids.
There are various shapes of animal viruses, such as helical and icosahedral. The shape of the Ebola virus is long like a thread. The genetic material of animal viruses is made of double-stranded DNA or RNA, single-stranded DNA or RNA. They used to cause various types of diseases in animals and humans. Herpesvirus and poxvirus are viruses made of double-stranded DNA.
Examples of Animal Virus
The genetic material of hepatitis B, herpes, and pox virus is double-stranded DNA. The genetic material of parvovirus is single-stranded DNA. Picornavirus is a single-stranded RNA virus. R reovirus is a double-stranded RNA virus.
Difference between Plant Viruses and Animal Viruses
Important Questions
Q1. What are animal virus infections called?
Ans: Infections that occur through animal viruses are called zoonotic or viral zoonoses. Examples are rabies and yellow fever.
Q2. What are the main characteristics of plant viruses?
Ans: The most common shape of a plant virus is a rod shape with a protein disc forming a tube around the viral genome.
Q3. Are viruses living or nonliving?
Ans: Viruses are not made of cells so they can't be considered living but they are not also dead because they replicate inside the host cell.
Conclusion
In conclusion, we learnt that viruses are infectious microbes that are made of protein and genetic material. Plant and animal viruses cause infection in plants and animals, respectively. We have also studied a table listing the differences between plants and animal viruses. We hope to have helped you with your queries. You can go through the important and practise questions to test your knowledge as well the following links for further readings.
FAQs on Difference Between Plant Virus and Animal Virus in Detail
1. What is the main difference between plant virus and animal virus?
The main difference between plant viruses and animal viruses lies in their mode of transmission and host cell entry.
- Plant viruses usually enter through wounds and are transmitted by vectors like insects (e.g., aphids).
- Animal viruses enter through receptor-mediated endocytosis or membrane fusion.
- Plant viruses commonly spread via plasmodesmata, while animal viruses spread through body fluids or direct contact.
- Most plant viruses have RNA genomes, whereas animal viruses may have either DNA or RNA genomes.
2. How do plant viruses infect plant cells?
Plant viruses infect plant cells by entering through mechanical injuries and moving between cells via plasmodesmata.
- They cannot penetrate the rigid cell wall on their own.
- Entry usually occurs through wounds caused by insects, tools, or environmental damage.
- After entry, viral RNA or DNA replicates inside the host cell.
- The virus spreads cell-to-cell through plasmodesmata and systemically through the phloem.
3. How do animal viruses enter host cells?
Animal viruses enter host cells by binding to specific cell surface receptors and penetrating through membrane fusion or endocytosis.
- The viral surface proteins recognize and attach to host receptors.
- Entry occurs by endocytosis or direct fusion with the plasma membrane.
- The viral genome is released into the cytoplasm.
- Replication and assembly occur inside the host cell.
4. Do plant viruses and animal viruses have different structures?
Plant and animal viruses differ structurally mainly in the presence of an envelope and capsid shape.
- Most plant viruses are non-enveloped and have a helical capsid (e.g., Tobacco mosaic virus).
- Animal viruses may be enveloped or non-enveloped.
- Animal viruses show diverse shapes such as icosahedral, helical, or complex forms.
5. What type of genetic material is found in plant viruses and animal viruses?
Plant viruses mostly contain single-stranded RNA (ssRNA), while animal viruses can contain either DNA or RNA.
- Most plant viruses have positive-sense ssRNA genomes.
- Animal viruses may have single-stranded or double-stranded DNA or RNA.
- Examples include Influenza virus (RNA) and Herpes simplex virus (DNA).
6. How are plant viruses transmitted compared to animal viruses?
Plant viruses are mainly transmitted by insect vectors, whereas animal viruses spread through direct contact, air, or body fluids.
- Plant viruses are commonly spread by aphids, whiteflies, nematodes, or contaminated tools.
- They may also spread through seeds or vegetative propagation.
- Animal viruses spread via respiratory droplets, blood, sexual contact, or vectors like mosquitoes.
7. Why can’t plant viruses enter cells the same way as animal viruses?
Plant viruses cannot enter like animal viruses because plant cells have a rigid cell wall that blocks direct viral entry.
- Animal cells lack a cell wall and allow receptor-mediated entry.
- The plant cell wall prevents membrane fusion or endocytosis by viruses.
- Therefore, plant viruses require mechanical damage or vectors to infect cells.
8. What are examples of plant viruses and animal viruses?
Examples of plant viruses include Tobacco mosaic virus (TMV), while examples of animal viruses include HIV and Influenza virus.
- TMV infects tobacco and other plants, causing mosaic patterns on leaves.
- HIV infects human immune cells.
- Influenza virus causes respiratory infections in animals and humans.
9. Do plant viruses cause diseases similar to animal viruses?
Plant viruses and animal viruses both cause diseases, but their symptoms differ based on the host organism.
- Plant viral diseases cause leaf mosaic, yellowing, stunted growth, and reduced yield.
- Animal viral diseases may cause fever, inflammation, immune suppression, or organ damage.
- Both interfere with normal cellular metabolism and reproduction.
10. What are the key structural and functional differences between plant virus and animal virus?
The key structural and functional differences between plant virus and animal virus involve entry method, genome type, and transmission.
- Entry: Plant viruses enter through wounds; animal viruses use receptor-mediated mechanisms.
- Cell barrier: Plant cells have a rigid cell wall; animal cells do not.
- Genome: Plant viruses mostly contain ssRNA; animal viruses contain DNA or RNA.
- Transmission: Plant viruses rely on vectors like insects; animal viruses spread through air, fluids, or contact.
