ANSWER THE FOLLOWING Each IN 250 words. Need ASAP. Do not plagerize. Answer questions as if you were teaching the answer. If you use sources, please cite them in APA Format XXXXXXXXXXcurrent...

Viruses are acellular pathogens. They do not belong to any kingdom. Whenever we talk about
viruses we also include viriods and prions. These are obligate intracellular parasite. They can’t
grow on their own, they require host organism for their survival. They have dimension of
nanometer. They are small enough to be filtered.The have nucleic acid as their genetic
material. They contain either DNA or RNA, not both. They lack metabolic abilities.
Viruses basically consist of nucleic acid( DNA or RNA) and protein coat. Viruses cause infection
either by lysing the cell or changing its overall mechanism. Virus attaches itself to host cell and
releases its nucleic acid in the host cell. Virus nucleic aci uses host machinery for its replication.
Infected cells can’t carry out normal cell function because its machinery is being over used for
production of virus protein coat. Usually extracellular viruses are called virion particles.A virion
contains a protein coating called a capsid. The capsid surrounds the nucleic acid (either DNA
or RNA). Together with the capsid and the DNA or RNA core is called a nucleocapsid. Some
virions also contain an envelope which is made up of a phospholipid membrane. Capsid and
envelop plays important role for protection of virus.
Viriods consist of nucleic acid part of virus. They often contain only RNA. They often carried
along with viruses.. For example, Hepatitis D is a viroid that is carried along with the capsid of
the Hepatitis B virus.
Prions are the only protein part of the viruses. They generally alter the individuals DNA thus
inducing production of altered protein . This altered form cannot be broken down host cell.
Thus this will accumulates and eventually causing cell death.
Ans: As we have discussed in previous question. The viruses are very small sized particles of
the size of nanometers. They are considered a cellular pathogen. They can infect cell enter cell
ytic phase and lead to eventually burst down of the cell or in the lysogenic phase where they
manipulate the host genome.
Virus consists of genetic material and protein coat. The genetic material could be ds DNA,
ssDNA, dsRNA, ssRNA. . Viruses can be found either inside a cell (intracellular) or outside of a
cell (extracellular). If it is found extracellular, the virus is called a virion. A virion contains a
protein coating called a capsid, which surrounds the core of the virus containing the nucleic
acid (either DNA or RNA). Together with the capsid and the DNA or RNA core is called a
nucleocapsid. Some virions also contain an envelope which is made up of a phospholipid
membrane. Both the capsid and the envelope are important in protection and providing shape
to the virus.
Viroids have no protein coat, but are only the nucleic acid (RNA). Because of this, they are
often carried around inside viruses. For example, Hepatitis D is a viroid that is carried in the
capsid of the Hepatitis B virus
As we have discussed earlier prions consist of protein part of viruses. They are infectious
protein particle called Prp. All mammals generally has the gene responsible for PrP.
Development of prion PrP only occurs in excess production of PrP or due to the formation of
prion PrP. This altered form cannot be broken down by your cells and it therefore
accumulates, eventually causing cell death as it needs more and more space



Ans: Physical characteristic:
Morphology: very small (10nm to 200nm)
Physiology: none( obligate parasite)
Nucleocapsid:
nucleic acid - viral genes can be either dsDNA, ssDNA , dsRNA or ssRNA.
capsid - protein coat made up of capsomeres subunits. The major function of protein is to
transfer nucleic acid from virus to host cell. The protein determines the infectious property of
virusesThe host immune response treat these proteins as antigensand identifies these proteins
or glycoproteins exposed on the surface of the virus particle. Some surface proteins may also
exhibit specific activities. Influenza virus hemagglutinin agglutinates red blood cells
Envelope:This membrane is formed during the budding process when virus leaves the host cell.
Only few animals viruses have these membrane. This membrane helps in virion integrity
Viral Glycoproteins:
Viral envelopes contain glycoproteins. The sugars added to viral glycoproteins often reflects
the host cell in...