TEST 3 Flashcards
1
Q
What is immunology?
A
Study of how the body responds to and resists foreign pathogens and substances
2
Q
What is the origin of the term ‘immunity’?
A
Comes from Latin Immunis, meaning ‘exempt’
3
Q
Name the types of pathogens.
A
- Viruses
- Bacteria
- Parasites
- Fungi
4
Q
What is the fatality rate of smallpox?
A
30% fatality rate
5
Q
How many people died from smallpox in the 20th century?
A
300-500 million
6
Q
Who introduced smallpox to the New World?
A
Cortes in 1520
7
Q
What was the effect of smallpox on the Aztecs?
A
Killed 60-90% of Aztecs
8
Q
What is variolation?
A
Deliberate infection with smallpox
9
Q
What is the effectiveness of variolation?
A
1% fatality vs 30% fatality in unvariolated
10
Q
Who is known for the first rabies vaccine?
A
Joseph Meister
11
Q
What is the incubation period for Ebola?
A
2-21 days
12
Q
List symptoms of Ebola.
A
- Fever
- Fatigue
- Muscle Pain
- Headache
- Sore Throat
- Vomiting
- Diarrhea
- Rash
13
Q
What is the average fatality rate for Ebola?
A
Approx 50%
14
Q
What is one method of transmission for Ebola?
A
Human to human via direct contact with body fluids
15
Q
What is the primary method for diagnosing Ebola?
A
Lab testing under maximum biological containment conditions
16
Q
What is the difference between smallpox and chickenpox regarding prodrome symptoms?
A
Smallpox has febrile symptoms 1-4 days prior to lesions; chickenpox has no prodrome symptoms
17
Q
What are the three lines of defense in the immune system?
A
- Innate
- Adaptive
- Inflammatory
18
Q
What is the function of C3b in opsonization?
A
Binds to targets & triggers phagocytosis
19
Q
What types of lymphocytes are involved in humoral immunity?
A
B Cells
20
Q
What role do T Cells play in the immune system?
A
Cell mediated immunity
21
Q
Describe the structure of an antibody.
A
- 2 Light Chains
- 2 Heavy Chains
22
Q
What is the function of IgG antibodies?
A
Long term immunity and memory antibodies
23
Q
How is clonal selection related to the immune response?
A
Generates B & T Cells appropriate to the invader
24
Q
What is the significance of the C regions in antibody structure?
A
Constant Heavy Regions determine class
25
What is the common treatment for inflammatory diseases?
Anti-inflammatories like aspirin and NSAIDs
26
What is the role of macrophages in the inflammatory response?
Engulf bacteria and cell debris
27
What are the characteristics of inflammation?
* Pain
* Swelling
* Redness
* Heat
* Loss of Function
28
What is the role of interleukin 6 in inflammation?
A marker for inflammation produced by macrophages and T cells
29
What is the incubation time for rabies?
Weeks to years
30
What is the main cause of polio?
Spread from feces to oral route to the CNS
31
What are the two main types of polio vaccines?
* Salk (Inactivated Injection)
* Sabin (Oral Attenuated)
32
What is the average number of cases of polio in the US in 2019?
3 or less cases
33
What is Pasteurization?
Heating almost to boiling for 30 minutes & cooling to kill most microbes
34
What is the significance of Benjamin Jetsy's work?
Inoculated with cowpox to prevent smallpox
35
What are the symptoms of rabies?
* Foam at mouth
* Aggression
* Paralysis
36
What is the average case fatality rate for Ebola outbreaks?
25% - 90%
37
What is the role of the lymphatic system?
Excretes toxins, waste & pathogens
38
How many lymph nodes do humans typically have?
500-600 nodes
39
What is the role of lysozymes?
Found in tears, they have pesticide properties
40
Fill in the blank: The __________ response is activated by exposure to antigens.
adaptive
41
True or False: All lesions in smallpox appear at different stages.
False
42
What is the function of Treg cells?
Regulate immune responses
43
What is the role of phagocytic cells?
Consume foreign bodies and kill infected cells
44
Who discovered acquired immunological tolerance?
Sir Macfarlane Burnet and Medawar
45
What type of immunity develops when a person's immune system responds to a foreign substance?
Acquired immunity
46
What cells recognize and bind with antigens?
B Cells
47
What happens 1-2 weeks after exposure to an antigen?
Clone of effector cells are produced
48
What is true about secondary immune responses compared to primary responses?
They are always stronger and faster
49
What process involves phagocytic cells breaking microbes into antigen fragments?
Humoral infections
50
What binds to antigens and displays them on the surface for T Cells?
Self-made proteins
51
What activates T Cells?
Self-Nonself complex
52
What are the two main types of immune responses mediated by B Cells and T Cells?
* Humoral Immune Response
* Cell-mediated Immune Response
53
What are cytotoxic T Cells responsible for?
Killing virally infected cells
54
What complex do cytotoxic T Cells use to find infected cells?
HLA (I)-AG-TCR-CD8 Complex
55
What do cytotoxic T Cells synthesize to lyse infected cells?
Perforin proteins
56
What is a risk group for vaccines?
* Close Quarters Residents
* University Students
* Military
* Elderly
57
What diseases are associated with international travelers that require vaccination?
* Cholera
* Yellow Fever
* Plague
* Typhoid
* Hepatitis
58
What is herd immunity?
A method of protecting a community by immunizing a critical mass of the populace
59
What is the R Naught (R0)?
Basic reproduction number of a disease
60
What is the R Naught for COVID-19?
1.4-2.4
61
What are the benefits of vaccination?
* Prevent diseases
* Creates Herd Immunity
* Can eradicate diseases
* Relatively Cheap
62
What are the two types of immunities based on origin?
* Passive
* Active
63
What type of hypersensitivity is IgE mediated?
Type 1
64
What are allergens?
Substances that induce a Type 1 hypersensitive reaction
65
What is the PK Reaction used for?
To demonstrate that allergies are mediated by antibodies
66
What is systemic anaphylaxis?
Severe allergic reaction that can lead to death via asphyxia or vascular collapse
67
What is a common treatment for anaphylaxis?
Epinephrine injection
68
What do dust mites prefer in their environment?
High humidity (75%+) in bedding and carpets
69
What is the goal of hypo-sensitization treatments?
Shift TH2 to TH1 response
70
What is the main cause of erythroblastosis fetalis?
RH reaction when an RH- mother is exposed to RH+ fetal blood
71
What are examples of autoimmune diseases?
* Lupus
* Insulin-Dependent Diabetes (Type 1)
* Multiple Sclerosis
* Rheumatoid Arthritis
72
What characterizes immunodeficiency diseases?
Lack of one or more components of the immune system
73
What virus is associated with AIDS?
HIV
74
What is the significance of Griffith's transformation experiment?
Bacteria can transfer genetic material
75
What did the Hershey-Chase experiment demonstrate?
DNA is the genetic material
76
What are Chargaff's Rules?
A & T have equal numbers and C & G have equal numbers in any species
77
What technique did Wilkins and Franklin use to study DNA?
X-ray Crystallography
78
What is the semiconservative model of DNA replication?
Each daughter cell has one old conserved strand and one new strand
79
What enzyme relieves the strain of twisting of the helix during DNA replication?
Topoisomerase
80
What is the main function of primase in DNA replication?
Places a primer for DNA polymerases to add nucleotides
81
What is the difference between eukaryotic and prokaryotic DNA replication?
* Eukaryotic: Linear DNA, multiple origins of replication
* Prokaryotic: Circular DNA, one origin of replication
82
What is the Trombone Model in DNA replication?
The lagging strand forms a loop for coordination of synthesis
83
What is the function of Topoisomerase?
Topoisomerase helps in relieving the strain of unwinding DNA during replication.
84
What role does Primase play in DNA replication?
Primase synthesizes short RNA primers to initiate DNA synthesis.
85
What is the primary function of DNA Polymerase III?
DNA Pol 3 is responsible for synthesizing new DNA strands during replication.
86
What is the function of DNA Polymerase I?
DNA Pol 1 replaces RNA primers with DNA nucleotides and repairs damaged DNA.
87
What is the role of Ligase in DNA replication?
Ligase connects Okazaki fragments on the lagging strand by forming phosphodiester bonds.
88
What constitutes the Replication Complex?
The Replication Complex is formed by many proteins that work together during DNA replication.
89
What does the Trombone Model describe in DNA replication?
The Trombone Model describes how the lagging strand forms a loop to allow leading and lagging strand enzymes to coordinate.
90
What role do DNA Polymerases play in proofreading?
DNA Polymerases proofread newly synthesized DNA and replace incorrect nucleotides.
91
What is Mismatch Repair?
Mismatch Repair involves repair enzymes correcting errors in base pairing.
92
What is Nucleotide Excision Repair?
Nucleotide Excision Repair is a mechanism where endonucleases cut out and replace damaged stretches of DNA.
93
What is the significance of mutations in evolution?
Mutations introduce genetic variation, which is essential for natural selection and speciation.
94
What are Telomeres?
Telomeres are repetitive noncoding DNA sequences at the ends of chromosomes that protect genes from erosion.
95
How are Telomeres connected to aging?
Shortening of telomeres is proposed to be linked to aging and cellular senescence.
96
What is the Hayflick Limit?
The Hayflick Limit refers to the number of times a normal somatic human cell can divide before cell division stops.
97
What is Telomerase?
Telomerase is an enzyme that lengthens telomeres in germ cells and is categorized as a Ribonucleoprotein.
98
What are the two stages of Gene Expression?
Gene Expression occurs in two stages: Transcription and Translation.
99
What is the Central Dogma of Molecular Biology?
The Central Dogma describes the flow of genetic information: DNA -> RNA -> Protein.
100
What is the function of tRNA in translation?
tRNA transfers specific amino acids to the growing polypeptide chain during translation.
101
What is the structure of a tRNA molecule?
tRNA consists of a single RNA strand that is about 80 nucleotides long and has a cloverleaf shape.
102
What are codons?
Codons are triplet sequences of nucleotides in mRNA that specify amino acids.
103
How many codons are there, and what is their significance?
There are 64 codons; 60 code for amino acids, 3 are stop codons, and 1 is a start codon.
104
What is the role of RNA Polymerase in transcription?
RNA Polymerase catalyzes the synthesis of RNA from the DNA template.
105
What is the TATA Box?
The TATA Box is a promoter sequence that helps initiate transcription in eukaryotes.
106
What are Introns and Exons?
Introns are noncoding regions of RNA, while Exons are coding sequences that are expressed.
107
What is alternative splicing?
Alternative splicing allows a single gene to produce multiple polypeptides by including different combinations of exons.
108
What is the function of Ribozymes?
Ribozymes are catalytic RNA molecules that can splice RNA and function as enzymes.
109
What are the three stages of translation?
The three stages of translation are Initiation, Elongation, and Termination.
110
What happens during the termination stage of translation?
Termination occurs when a stop codon is reached, leading to the release of the polypeptide.
111
What are signal peptides?
Signal peptides are short amino acid sequences that direct the transport of proteins to their destination.
112
What are the two populations of ribosomes?
The two populations of ribosomes are Free ribosomes and Bound ribosomes.
113
What are Point Mutations?
Point mutations are changes in a single base pair in the DNA sequence.
114
What are the types of Point Mutations?
Types of Point Mutations include Substitutions, Missense, Silent, and Nonsense mutations.
115
What is a Frameshift Mutation?
Frameshift mutations occur due to insertions or deletions, altering the reading frame of the genetic code.
116
What are the types of RNA?
* tRNA
* mRNA
* rRNA
* pre-mRNA
117
Define a Gene.
A gene is a discrete unit of inheritance that codes for a specific polypeptide chain.
118
What is a Structural Gene?
A structural gene is a region of DNA that can be expressed to produce a final functional product.
119
What is the function of a Regulatory Gene?
A regulatory gene controls the expression of one or more structural genes by regulating transcription.
