Viriods and prions, Biology

Assignment Help:

Viriods and Prions

Viroids 

      In 1971, T.O.Diener reported that the  spinde tuber disease of potato causing gnarling and cracking of the tuber, is caused by multiplication of a pathogen much smaller than viruses and present in tuber cells themselves, This pathogen found to be a free short and circular RNA strand of about 300nucleotides. Diener  named it viroid. It was found that viroids are infectious because, after multiplying  in a plant cell, these disperse in the tissue and invade new cells. About a dozen plant diseases have since been shown to be caused by viroids.it is also possible that the causative agents of some more plant and animals diseases turn out to be viroides.

Prions

While searching for the cause of a mental disease kuru widespread in a tribe of New Guinea, D,C Gajdusek(1968) discovered that the disease is caused  by a slow virus infection. He shared the 1976 Nobel Prize this work. Later he suspected that other neurological disorders. Like mad cow disease in cows and human dementia and Parkinson disease might also be of this  category, Prisoner (1985) speculated that Creulzfeldt Jacob disease extremely   minute (4-6 nm in diameter ) protein particles which are coded by the genome of certain brain cells, and act as infectious pathogens, These particles have been named prions.


Related Discussions:- Viriods and prions

Explain the work of john ray in animal taxonomy, Explain the Work of John R...

Explain the Work of John Ray in Animal Taxonomy? The first important work on both animal and plants was initiated by John Ray (1627-1705). He followed Aristotle and divided ani

Original cell progresses to the g2, A cell in G1 of interphase has 12 chrom...

A cell in G1 of interphase has 12 chromosomes. How many chromosomes and DNA molecules will be found per cell when this original cell progresses to the G2?

What is a biome, What is a biome? A biome is a prevailing ecosystem con...

What is a biome? A biome is a prevailing ecosystem constituted by same biotic and abiotic factors present in one or more regions of the planet.

Asexual reproduction in animals, Asexual Reproduction in Animals Repro...

Asexual Reproduction in Animals Reproduction may be referred as production of true copies. Most of the animals that are quite familiar to us generate male and female gametes (

Hypothermia-open heart surgery, Hypothermia :  Hypothermia reduces the met...

Hypothermia :  Hypothermia reduces the metabolic requirements of the body thereby reducing oxygen consumption. It also preserves high-energy phosphate stores of the body. At norma

Why in the f1 generation is one of the colors missing?, Considering the hyb...

Considering the hybridization in a trait like the color of the flowers of a given plant species (red/yellow) conditioned by a pair of different alleles in relation to complete domi

Differences between mitosis and meiosis, DIFFERENCES BETWEEN MITOSIS AND...

DIFFERENCES BETWEEN MITOSIS AND MEIOSIS    EVENTS  MITOSIS  MEIOSIS  Occurrence  In all the body cells including

Define the qualitative technique in nutritional biochemistry, Define the Qu...

Define the Qualitative Technique in Nutritional Biochemistry? In this manual you will be familiarized with simple qualitative techniques and tests to identify compounds such as

Patters of cleavage, Patters of Cleavage In most of the animal groups...

Patters of Cleavage In most of the animal groups with spherical or almost spherical egg and little or moderate amount of yolk (micro-or mesolecithal eggs), the first and seco

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd