VIRUSES, VIROIDS, AND PRIONS

Question 1

are very tiny organisms that
can cause diseases in living things.

Answer 1

viruses

Question 2

key components of virus

Answer 2

capsid, envelope, genome

Question 3

general characteristics of virus

Answer 3

genetic material
host dependency
diverse shapes

Question 4

or protein shell, of a virus
is made up of many protein molecules.

Answer 4

capsid

Question 5

These capsids are
named after their
linear, thin, thread-like
appearance. They
called rod-shaped or
helical.

Answer 5

helical

Question 6

have twenty faces, and
are named after the
twenty-sided shape
called an icosahedron.

Answer 6

icosahedral

Question 7

These capsids are kind of a
hybrid between the helical and
icosahedral shapes. They
basically consist of an
icosahedral head attached to a
helical tail.

Answer 7

complex

Question 8

A lipid bilayer that surrounds
some viruses, derived from the
host cell’s membrane.

Answer 8

viral envelope

Question 9

s are infectious pathogens that
affect only plants, therefore are also
called plant pathogens.

Answer 9

viroids

Question 10

general charcteristics of viroids

Answer 10

infectious rna molecules, no protein encoded, transmission via seeds

Question 11

It refers to abnormal, pathogenic
agents that are transmissible and are
able to induce abnormal folding of
specific normal cellular proteins

Answer 11

prions

Question 12

general characteristics of prions

Answer 12

proteinaceous, infectious

Question 13

These prion proteins are found on the cell membrane and play
an important role in cell signalling and cell adhesion. More
research is being carried out to discover its functions.

Answer 13

PrPc

Question 14

This is the disease-causing prion and is resistant to proteases. It
affects the confirmation of PrPc and changes it. They are
believed to have more beta sheets than the alpha helices.

Answer 14

PrPsc

Question 15

the bacteriophage takes
over the cell, reproduces new
phages, and destroys the cell

Answer 15

lytic cyle

Question 16

the phage genome
integrates into the bacterial
chromosome and becomes part of
the host.

Answer 16

lysogenic cycle

Question 17

the first
stage in the infection process in which
the phage interacts with specific
bacterial surface receptors.

Answer 17

attachments

Question 18

This occurs through contraction of the tail sheath, which acts like a hypodermic
needle to inject the viral genome
through the cell wall and membrane.
The phage head and remaining
components remain outside the
bacteria

Answer 18

penetration

Question 19

After entering the host cell, the virus
synthesizes virus-encoded endonucleases to degrade the
bacterial chromosome.

Answer 19

biosynthesis

Question 20

new virions are created. To liberate free phages, the bacterial cell wall is disrupted by phage
proteins such as holin or lysozyme.

Answer 20

maturation

Question 21

Mature viruses burst out of the host cell
in a process called lysis and the progeny viruses are liberated into the environment to infect new
cells

Answer 21

release

Question 22

lytic cycle

Answer 22

attachment, penetration, biosynthesis, maturation, release

Question 23

life cycle of viruses with animal hosts

Answer 23

attachment, penetration, uncoating, biosynthesis, assembly, release

Question 24

It occurs when a virus is not completely cleared from the system of the host but stays in certain tissues or organs of the infected person.

Answer 24

persistent infections

Question 25

infects many cells throughout the
body and causes chickenpox, characterized by a
rash of blisters covering the skin

Answer 25

varicellazoster virus

Question 26

These types of viruses are known
as latent viruses and may cause latent
infections. Viruses capable of latency may initially cause an acute infection before becoming dormant.

Answer 26

latent infections

Question 27

remaining hidden or dormant inside the cell

Answer 27

latency

Question 28

a disease with symptoms that are recurrent or persistent over a long time.

Answer 28

chronic infections

Question 29

lead to the death of the cell through cell
lysis.

Answer 29

virulent phages

Question 30

can become part of a host
chromosome and are replicated with the cell genome until such time
as they are induced to make newly assembled viruses

Answer 30

temperate phages

Question 31

results, in part, from the
uncontrolled reproduction
(mitosis) of a single cell

Answer 31

cancer

Question 32

clone of abnormal cell

Answer 32

tumor