Micro 5,11

Since 2000, the number of orders of viruses recognized by the International Committee on the Taxonomy of Viruses has risen from _______ to ________.

1:8

What percentage of human DNA is thought to consist of viral DNA sequences?

8

what is the primary reason why it is more difficult to design antiviral drugs than antibacterial drugs

Antiviral drugs often must target host cell functions which results in side effects in the host.

The principal government agency responsible for tracking infectious diseases in the United States is the _____.

Centers for Disease Control and Prevention

Reverse transcriptase synthesizes

DNA from RNA

Viruses attach to their hosts via

Host glycoproteins

One of the principal capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a(n) _____ capsid.

Icosahedral

Who created the rabies vaccine using a filter?

Pasteur

infectious agents that are noncellular

Prions, Satellite Viruses, Viroids

what is the role of viral surface proteins or spikes

Provide means of attachment to host cell surface

What is not a typical capsid shape?

Tetrahedral

what is true regarding reportable diseases?

There are over 75 reportable diseases caused by a large variety of microorganisms.

Why do antiviral medications often have side effects?

Viruses are intracellular pathogens, and therefore, there is often host cell damage with antiviral treatments

A _______ is the presence of small numbers of bacteria in the blood.

bacteremia

Of all infectious agents, which group has the most variety of drugs designed to treat infections?

bacteria

Animals that participate in the life cycles of pathogens and transmit pathogens from host to host are ____

biological vectors

The suffix -emia means _______.

blood

Helical and icosahedral are terms used to describe the shapes of a virus _____.

capsid

Opportunistic pathogens

cause disease in compromised individuals

what characteristics are exhibited by endtoxins

composed of lipopolysaccharide heat stable fever inducing

What is not a characteristic of a transformed cell?

decreased growth rate

The movement of molecules from an area of high concentration to an area of lower concentration is called _____.

diffusion

An infectious agent already existing on or in the body is called _____.

endogenous

what is not associated with every virus

envelope

what describes a virus that has a membranous outer covering over its capsid, partially derived from a host cell.

enveloped virus

Microbial hyaluronidase, coagulase, and streptokinase are examples of

exoenzymes

A teacher walking through her first-grade classroom pauses to pick up a used tissue that had ended up on the floor instead of in the waste basket. Unfortunately, after discarding the tissue, she doesn't immediately wash her hands, and acquires a strain of rhinovirus. Several days later she begins to experience symptoms of a cold. Based upon this scenario, please select the mode of disease transmission demonstrated here.

formite

An inanimate object that harbors and transmits a pathogen is a _____.

formite

Viruses attach to their hosts via ________.

host glycoproteins

The number of new cases of a disease in a population over a specific period of time compared with the healthy population is the _____.

incidence rate

An endotoxin is

indicative of gram-negative organisms

The activation of a prophage is called _____.

induction

patterns of direct transmission of infectious disease are

kissing and touching droplet

Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms are called _____.

latent

example of an endotoxin

lipopolysaccharide

New, nonenveloped virus release occurs by _____.

lysis

When phage nucleic acid is incorporated into the nucleic acid of its host cell and is replicated when the host DNA is replicated, this is considered part of which cycle?

lysogenic cycle

This occurs when a bacteriophage infects bacteria and the bacteria are ruptured or lysed

lytic infection

Microorganisms require large quantities of _____ for use in cell structure and metabolism.

macronutrients

Viruses lack the ability to

metabolize

The number of persons afflicted with an infectious disease is the _______ rate.

morbidity

Resident biota are found in/on the ________.

mouth skin large intestine nasal passages

A negative-sense RNA virus ________.

must synthesize a positive RNA copy of its genome

Viruses are usually _________ in size, and their structure is best viewed through the use of ________ microscopy.

nanometers; electron

A naked virus only has a(n)

nucleocapsid

In general, most DNA viruses multiply in the host cell's _______, while most RNA viruses multiply in the host cell's _______.

nucleus, cytoplasm

an organism that lacks superoxide dismutase and catalase enzyme

obligate anaerobe

Uncoating of viral nucleic acid ________.

occurs before replication involves enzymatic destruction of the capsid releases viral nucleic acid into the cell does not occur in bacteriophage multiplication

Mammalian viruses capable of starting tumors are

oncoviruses

Most of the dry weight of a microbial cell is from

organic compounds

diffusion of water through a selectively permeable membrane

osmosis

Clear patches in cell cultures that indicate sites of virus infection are called ________.

plaques

The percentage of the population with a particular disease at any point in time is the _______ of disease, whereas the number of new cases over a given time period is the _______ of disease.

prevalence; incidence

Infectious protein particles are called

prions

Exotoxins are

proteins

viral spikes

protrude from the envelope.

what cannot find a location in or on body tissues suitable for growth

psychrophiles

The host cells that viruses can infect are determined by the ____________.

receptors of the host cells

All protein synthesis takes places in the hosts

ribosomes

organisms that feed on dead organisms for nutrients

saprobes

what is not a factor that weakens host defenses against infections?

strong healthy body

The toxic superoxide ion is converted to harmless oxygen by two enzymes

superoxide dismutase and catalase

What structures are used by bacteriophages to attach to host cell receptors?

tail fibers

What type of phage enters an inactive prophage stage?

temperate

A virus that undergoes lysogeny is a/an _________.

temperate phage

Pathogenic microbes that cause disease in healthy people are called _____

true pathogens

Host range is limited by

type of host cell receptors on cell membrane

The term autotroph refers to an organism that

uses CO2 for its carbon source

Rather than developing more antiviral medications, what is a more common focus for researchers when it comes to viral disease?

vaccine development

An animal, such as an arthropod, that transmits a pathogen from one host to another is a _____.

vector

Animals that participate in the life cycles of pathogens and transmit pathogens from host to host are ____

vector

Tooth decay develops when human saliva and proteins aggregate on the tooth and provide a hospitable surface for a range of microbial species to develop into a biofilm. These organisms ferment carbohydrates and the acid byproducts erode the enamel, forming caries. Tooth decay is therefore considered to be _____.

a polymicrobial infection

Creutzfeldt-Jacob disease is ________.

a spongiform encephalopathy of humans