BIL 150 Chapter 43: The Immune System || WELL-
ENLIGHTENED
Pathogens correct answers Are agents that cause disease, such as bacteria, viruses, fungi, or
other
Immune system correct answers *Enables animals to avoid or limit many infections*; A
system (including the thymus and bone marrow and lymphoid tissues) that protects the body
from foreign substances and pathogenic organisms by producing the immune response
Innate immunity correct answers Immunity that is present before exposure and effective from
birth. Responds to a broad range of pathogens; a defense active immediately upon
infection.*; Each of a small set of receptors recognizes a molecule absent from animals, but
common to a type of pathogen, as shown by these examples.
Does innate system include barrier defenses? correct answers Yes, it does include barriers
such as skin, mucous membranes and secretions
What is a type of immunity that is special to vertebrates? correct answers Adaptive immunity
Adaptive immunity correct answers The ability to recognize and remember specific antigens
and mount an attack on them; *it is activated after the innate response and develops more
slowly.*
What are the different ways immune cells recognize pathogens in *innate recognition*?
correct answers Each of a small set of receptors recognizes a molecule absent from animals,
but common to a type of pathogen, as shown by these examples.
For a virus, *dsRNA*, which is nucleic acid unique to viral genomes are recognized.
For a bacterium, *flagellin,* a protein in a bacteria's flagella is recognized
For a fungus, *mannan,* an oligosaccharide in the cell wall of fungi
How do immune cells recognize pathogens in *adaptive recognition*? correct answers Each
of a vast number of receptors (of an immune cell) is *specific for a particular part of a
protein* in one pathogen, such as a surface protein of the influenza (flu) virus.
What are the mechanisms of innate immunity in invertebrates? correct answers -In insect,
they have exoskeleton made of *chitin* that acts as a barrier
-Their digestive system also has *chitin-based barrier* and *lysozyme,* which is an enzyme
that breaks down bacterial cell walls
-They also produce recognition proteins, each of which binds a molecule common to a large
class of pathogens (like a protein that binds to bacteria)
-They have immune cells called *hemocytes*
, Lysozyme correct answers An enzyme that destroys bacterial cell walls; in mammals, found
in sweat, tears, and saliva and are found in the digestive system of invertebrates
Hemocytes correct answers *Immune cells* that circulate within the hemolymph *of insects*
and ingest foreign substances by *phagocytosis*; secrete antimicrobial peptides
Phagocytosis correct answers A type of endocytosis in which a cell engulfs large particles or
whole cells
How do hemocytes get rid of pathogens? correct answers 1. Hemocytes can become
phagocytotic and then ingest and break down microorganisms
2. The binding of recognition proteins to a fungal cell wall molecules activates a
transmembrane receptor called *Toll.* The *Toll* then activates and production and
secretion of *antimicrobial peptides* that kill fungal cells.
How is viral RNA dealt with in insects? correct answers Viruses that infect insects have a
genome consisting of a single strand of RNA. This is converted into double-stranded RNA
inside the host cell, and the insect's cells recognize it as foreign and eliminate since animal
cells do not make double stranded RNA.
What are some innate defenses that both mammals and invertebrates share? correct answers
1. Barrier Defenses
2. Phagocytosis
3. Antimicrobial peptides
What is an innate defense that is unique to vertebrates? correct answers 1. *Natural Killer
cells*- cells that circulate the body and detect abnormal cells and release chemical which lead
to their death, inhibiting the spread of virally infected or cancerous cells
2. *Interferons*- proteins that provide innate defense by inhibiting the replication of viruses
3. *Inflammatory response*- a result of mast cells secreting *histamines* that led to a
increase in blood supply
Natural killer cells correct answers A type of white blood cell that can kill tumor cells and
virus-infected cells by circulating the body and detecting abnormal cells. If an abnormal cell
is found, the release chemicals that lead to the cell's death.
Interferons correct answers Proteins that provide innate defense by inhibiting the replication
of viruses, they can also help activate macrophages.
Inflammatory response correct answers Includes heat and swelling, is brought about by
molecules released upon injury or infection. *Mast cells,* immune cells found in connective
tissue, discharge cytokines, which signal *neutrophils* to come to the site of injury.
*Histamines are also released by mast cells, which triggers blood vessels to dilate and
become more permeable. This results in an increase in blood supply which produces the
inflammatory response. The enhanced blood supply facilitates the delivery of antimicrobial
peptides.*
ENLIGHTENED
Pathogens correct answers Are agents that cause disease, such as bacteria, viruses, fungi, or
other
Immune system correct answers *Enables animals to avoid or limit many infections*; A
system (including the thymus and bone marrow and lymphoid tissues) that protects the body
from foreign substances and pathogenic organisms by producing the immune response
Innate immunity correct answers Immunity that is present before exposure and effective from
birth. Responds to a broad range of pathogens; a defense active immediately upon
infection.*; Each of a small set of receptors recognizes a molecule absent from animals, but
common to a type of pathogen, as shown by these examples.
Does innate system include barrier defenses? correct answers Yes, it does include barriers
such as skin, mucous membranes and secretions
What is a type of immunity that is special to vertebrates? correct answers Adaptive immunity
Adaptive immunity correct answers The ability to recognize and remember specific antigens
and mount an attack on them; *it is activated after the innate response and develops more
slowly.*
What are the different ways immune cells recognize pathogens in *innate recognition*?
correct answers Each of a small set of receptors recognizes a molecule absent from animals,
but common to a type of pathogen, as shown by these examples.
For a virus, *dsRNA*, which is nucleic acid unique to viral genomes are recognized.
For a bacterium, *flagellin,* a protein in a bacteria's flagella is recognized
For a fungus, *mannan,* an oligosaccharide in the cell wall of fungi
How do immune cells recognize pathogens in *adaptive recognition*? correct answers Each
of a vast number of receptors (of an immune cell) is *specific for a particular part of a
protein* in one pathogen, such as a surface protein of the influenza (flu) virus.
What are the mechanisms of innate immunity in invertebrates? correct answers -In insect,
they have exoskeleton made of *chitin* that acts as a barrier
-Their digestive system also has *chitin-based barrier* and *lysozyme,* which is an enzyme
that breaks down bacterial cell walls
-They also produce recognition proteins, each of which binds a molecule common to a large
class of pathogens (like a protein that binds to bacteria)
-They have immune cells called *hemocytes*
, Lysozyme correct answers An enzyme that destroys bacterial cell walls; in mammals, found
in sweat, tears, and saliva and are found in the digestive system of invertebrates
Hemocytes correct answers *Immune cells* that circulate within the hemolymph *of insects*
and ingest foreign substances by *phagocytosis*; secrete antimicrobial peptides
Phagocytosis correct answers A type of endocytosis in which a cell engulfs large particles or
whole cells
How do hemocytes get rid of pathogens? correct answers 1. Hemocytes can become
phagocytotic and then ingest and break down microorganisms
2. The binding of recognition proteins to a fungal cell wall molecules activates a
transmembrane receptor called *Toll.* The *Toll* then activates and production and
secretion of *antimicrobial peptides* that kill fungal cells.
How is viral RNA dealt with in insects? correct answers Viruses that infect insects have a
genome consisting of a single strand of RNA. This is converted into double-stranded RNA
inside the host cell, and the insect's cells recognize it as foreign and eliminate since animal
cells do not make double stranded RNA.
What are some innate defenses that both mammals and invertebrates share? correct answers
1. Barrier Defenses
2. Phagocytosis
3. Antimicrobial peptides
What is an innate defense that is unique to vertebrates? correct answers 1. *Natural Killer
cells*- cells that circulate the body and detect abnormal cells and release chemical which lead
to their death, inhibiting the spread of virally infected or cancerous cells
2. *Interferons*- proteins that provide innate defense by inhibiting the replication of viruses
3. *Inflammatory response*- a result of mast cells secreting *histamines* that led to a
increase in blood supply
Natural killer cells correct answers A type of white blood cell that can kill tumor cells and
virus-infected cells by circulating the body and detecting abnormal cells. If an abnormal cell
is found, the release chemicals that lead to the cell's death.
Interferons correct answers Proteins that provide innate defense by inhibiting the replication
of viruses, they can also help activate macrophages.
Inflammatory response correct answers Includes heat and swelling, is brought about by
molecules released upon injury or infection. *Mast cells,* immune cells found in connective
tissue, discharge cytokines, which signal *neutrophils* to come to the site of injury.
*Histamines are also released by mast cells, which triggers blood vessels to dilate and
become more permeable. This results in an increase in blood supply which produces the
inflammatory response. The enhanced blood supply facilitates the delivery of antimicrobial
peptides.*
