the infectious agent that causes potato spindle tuber disease was discovered by

Viroid discovery Bagnall. By 1967–1968, it became clear to us, that the agent causing potato spindle tuber disease was not a conventional “virus” but a unencapsidated free ribonucleic acid (RNA) [13, 59].

Which causes potato spindle tuber disease?

Potato Spindle Tuber Viroid (PSTVd) is an EU listed quarantine pathogen of potatoes which causes stunting of the plant and malformation and cracking of tubers. The main host is potatoes but the disease also affects tomatoes and solanaceous ornamentals.

Who discovered viroids?

The pathogen is called a viroid by its discoverer, Dr. Theodor 0. Diener, to distinguish it from a virus.

What was discovered by TO Diener?

Viroids displaced viruses as the smallest known infectious agents.
...
Theodor Otto Diener.

Theodor O. Diener
Known for	Discovery of viroids
Awards	National Medal of Science (1987)
Scientific career
Fields	Plant pathology

Which of the following are present in infectious agent discovered by to diner?

Thus, the correct answer is 'Viroids.

Is Viroids smaller than virus?

Viroids are plant pathogens: small, single-stranded, circular RNA particles that are much simpler than a virus. They do not have a capsid or outer envelope, but, as with viruses, can reproduce only within a host cell. Viroids do not, however, manufacture any proteins.

What are absent in Viroids?

Absence of protein coat in viroid but present in virus. Presence of low molecular weight RNA in virus but absent in viroid. ... c.

Which disease is caused by Viroids?

The only human disease known to be caused by a viroid is hepatitis D. This disease was previously ascribed to a defective virus called the delta agent. However, it now is known that the delta agent is a viroid enclosed in a hepatitis B virus capsid.

Which plant virus is Gemini virus?

Geminiviruses (family Geminiviridae) are small single-stranded (ss) DNA viruses infecting plants. Their virion morphology is unique in the known viral world – two incomplete T = 1 icosahedra are joined together to form twinned particles. Geminiviruses utilize a rolling-circle mode to replicate their genomes.

Who gave the term virus?

In 1892, Dmitri Ivanovsky used one of these filters to show that sap from a diseased tobacco plant remained infectious to healthy tobacco plants despite having been filtered. Martinus Beijerinck called the filtered, infectious substance a "virus" and this discovery is considered to be the beginning of virology.

Who discovered free infectious DNA?

Complete Step by Step Answer: Theodor Otto Diener was a Swiss- American Plant pathologist who discovered small self- replicating particles which lacked protein coats and had infectious free RNA particles. He named these microorganisms as Viroid which meant L. virus- poison, eidos- diminutive.

What is the meaning of Viroids?

Viroid, an infectious particle smaller than any of the known viruses, an agent of certain plant diseases. The particle consists only of an extremely small circular RNA (ribonucleic acid) molecule, lacking the protein coat of a virus. ... Whether viroids occur in animal cells is still uncertain.

Who discovered viroids Class 11?

Viroids were first discovered by T.O. Diener in the year 1971. It was first examined in the potato spindle tuber viroid that caused a huge loss to the potato industry.

Which statement is wrong for viruses?

They have ability to synthesize nucleic acids by replication. Antibiotics do not acts against virus as they are made up of polymorphic protein coat. Viruses have different type of symmetry like icosahedral and helical. So, the correct answer is option B.

What is the difference between viroids and viruses?

Viroids are free RNA molecules of low molecular weight without any protein coat while viruses can have either RNA or DNA molecules encapsulated in a protein coat. Viroids are smaller in size than the viruses. Viroids infect only plants whereas virus infects all types of organisms.

Which of the following is not a viral disease?

Answer: (3)

Tuberculosis is an infectious disease produced by the tuberculosis bacterium Mycobacterium.

How can prions be destroyed?

To destroy a prion it must be denatured to the point that it can no longer cause normal proteins to misfold. Sustained heat for several hours at extremely high temperatures (900°F and above) will reliably destroy a prion.

Do prions have protein?

Prions are misfolded proteins with the ability to transmit their misfolded shape onto normal variants of the same protein. They characterize several fatal and transmissible neurodegenerative diseases in humans and many other animals.

What do viruses viroids and prions all have in common?

Viruses, viroids, prions, and some bacteria can all be considered pathogens. What do all pathogens have in common? They are all living and can cause an infectious disease. Prions were not widely known to be infectious agents until the 1980s.

What is the difference between viruses viroids and prions?

A viroid (an infectious RNA molecule) is similar to a virus but not quite the same thing. It's smaller than a virus and has no capsid. ... Prions (infectious protein particles) have neither DNA nor RNA to transmit infection.

Are viruses living or nonliving?

So were they ever alive? Most biologists say no. Viruses are not made out of cells, they can't keep themselves in a stable state, they don't grow, and they can't make their own energy. Even though they definitely replicate and adapt to their environment, viruses are more like androids than real living organisms.

What is the major difference between a virus and a viroid quizlet?

Viruses have capsids composed of protein, whereas viroids have no capsids.