Evolution and Human Health Flashcards
(30 cards)
The primary protein recognized, attacked, and remembered by the host’s immune system.
one of the two major surface proteins
Hemagglutinin
The specific parts of a foreign protein that the immune system recognizes and remembers
Antigenic sites
The estimated the rate of nucleotide substitution in the hemagglutinin gene to be approximately:
Fitch and colleagues
~6.7 × 10⁻³ per nucleotide per year
The amino acid replacements were analyzed to determine whether they occurred in:
Compared mutations in antigenic vs. non-antigenic regions
A viral protein is most responsible for determining host specificity
Nucleoprotein
The 1968 strains Victoria (H2N2) and Northern Territory (H3N2) shared closely related:
Nucleoproteins and neuraminidases
Where did the H3 gene in the 1968 human pandemic flu originate
The bird flu virus.
What gene besides hemagglutinin was also acquired by the 1968 strain from a bird virus
Polymerase gene PB1
The pigs involved in the origin of pandemic flu strains, according to the “mixing vessel” hypothesis
Pigs can be co-infected by bird and human strains—allowing gene mixing
A key explanation for how flu strains can have distantly related hemagglutinins but closely related nucleoproteins is:
Influenza viruses swap individual genes via reassortment
KatG gene is critical for the effectiveness of isoniazid
Encodes an enzyme that activates isoniazid inside the bacterium
Mutations in the KatG gene can cause resistance to isoniazid by
Disrupting drug activation by eliminating enzyme activity
The plasmid Tn3 in E. coli confers resistance to ampicillin by:
Encoding β-lactamase, which degrades the antibiotic
The bla gene carried on plasmids encodes an enzyme that
Breaks down β-lactam antibiotics like ampicillin
Rifampin resistance in Mycobacterium tuberculosis is associated with mutations in which gene
rpoB
Streptomycin interferes with bacterial growth by:
Binding a ribosomal protein, preventing protein synthesis
Mutations in which gene confer resistance to streptomycin in E. coli
rpsL
The sensitive E. coli outcompeted resistant strains in mixed cultures:
Resistance imposed a fitness cost
Best describes a compensatory mutation in antibiotic-resistant bacteria
A mutation that restores fitness without removing drug resistance
A recommendation would best reduce the selective pressure for resistance in non-target bacteria (bystanders)
Using narrow-spectrum antibiotics when possible
Levy advise against patients requesting antibiotics for colds and flu
Viral infections do not respond to antibiotics, encouraging resistance in bystander bacteria
A proposed mechanism linking continuous menstrual cycling to increased breast cancer risk
Repeated hormonal stimulation causing increased cell division in milk ducts
An environmental factor is suggested to interact with genetic predisposition to cause myopia in modern societies
Close-in visual work under artificial lighting
What virus is associated with breast cancer in mice and possibly in humans
Mouse mammary tumor virus (MMTV)
