Viruses
What are all viruses composed of?
All Viruses have genetic material and a capsid
List some ways your body responds to the influenza virus
Digestive - loss of appetite, nausea, vomiting
Muscular - joint and muscle aches
Nervous - headache, fever
Integumentary (skin) - chills
What are the three kinds of evidence we have for evolution
Fossils, anatomical structures, DNA evidence
What do antivrial medicines target?
Viruses, the medicine is new-ish and they do what antibiotics do but to viruses instead of bacteria - must stop the virus before maturation stage
Where did Darwin sail during his voyages as a naturalist?
South America and the Galapagos islands
What types of cells do flu viruses target?
epithelial cells lining the respiratory system
What is the difference between MHC 1 and MHC 2
MCH 1 are present on every nucleated cell of the body, the general self identification tag (general ID)
MHC 2 are only present on immune system cells that provide the link between the nonspecific and specific immune responses (general ID AND a specialized badge)
Difference between homologous and analogous structures?
Analogous - serve the same function, evolved independently as adaptations to a specific environment, ESSENTIALLY same physical appearance and job, different “bones”/structure, ex. bird wings, and butterfly wings both fly (but different structure)
Homologous - similar features, inherited from a common ancestor, ESSENTIALLY same bones/makeup, different physical appearance, ex. Humans, cats, whales, and bats all have the same hand/arm bones (humerus, radius, ulna, carpals, metacarpals, phalanges)
What branch of the immune system do vaccines assist?
The adaptive immune system
Where did Wallace travel as he made his observations of organisms?
South Pacific islands
Are Viruses alive? Why or why not?
Viruses are not alive because they cannot independently process energy or materials (they require a host cell to do so)
What are H and N spikes?
H spikes assist the virus in identifying receptors
N spikes help the virus enter the cell
What types of environmental pressures can lead to Natural Selection?
Stabilizing (more normal curve), balancing (when the mixed/middle trait is the benefit), directional (one extreme trait variant is most beneficial), disruptive (either the top or bottom extreme trait is most beneficial, in-between is a disadvantage).
What is different about how mRNA vaccines help produce antibodies
Modified form of MRNA that tells cells to make proteins that resemble diseases/viruses so antibodies can recognize the antigen on the virus once it is encountered in real life. No part of the virus gets injected, just the mRNA that instructs it to make the necessary antibodies
What was the status of Darwin and Wallace’s relationship and thoughts on Natural selection?
Darwin and Wallace both had very similar ideas on natural selection and Darwin used Wallaces findings to corroborate his theory. They weren’t besties but they were partners in their field of study (Darwin just wanted to make sure he got credit for finding natural selection first).
The virus immediately uses the host cells resources to manufacture new viruses
Key differences between the innate and adaptive immune system
You are born with an innate immune system and response does not improve with additional exposure. Adaptive immunity improves with time, requires activation, targets specific antigens, and has memory.
What is the difference between microevolution and macroevolution?
Micro - changes in alleles/genes within a population, can occur between generations, more favorable traits become more prevalent (rock pocket mice went from brown to black over just a couple generations)
Macro - accumulated changes/adaptations in a population, occurs over a LONGGG time, can result in a new species (wolf like mammals to whales over millions of years
Difference - Microevolution is a small trait change over a short time span, macroevolution is a huge change that can result in a whole new species over millions of years.
How are flu vaccines made?
Most common method - inject virus into fertilized chicken eggs where they incubate and replicate the virus. The egg white/liquid portion is extracted and the viruses in there are killed, virus parts are isolated, purified and used to make the vaccines. (This takes a long time, 6 months)
Newest process - uses a small (recombinant) weakened part of the influenza virus, the part used is protein associated with h spikes (antigens that are identified by the immune system), the h spike protein is used to make the vaccine and this is the most rapid form of vaccine production (no eggs)
What conditions did Darwin determine must be present for natural selection to occur?
The struggle for existence, genetic variation, and inheritance
How do viruses infect cells
Viruses infect cells by using their surface proteins (H and N spikes) to identify their specific target and enter into the target molecule. In there they modify DNA or RNA for virus reproduction.
What is histamine and how does that work in the immune response?
Histamine is an inflammatory chemical which slows movement of pathogens, increases blood flow to deliver additional WBCs (like macrophages) in an immune response
What are adaptations?
Not perfect, adaptation is a trade off (longer legs may mean you run faster but your bones are thinner and more breakable, gloves vs. mittens - more dexterity or warmer fingers) - Nature can only select naturally occurring variants natural selection builds on what is already there
In your own words, how does the flu vaccine work?
The vaccine provides a primary exposure to the antigen for a virus and allows the immune system to build memory to that virus so we have a stronger, faster response when we naturally encounter the virus.
Who came up with the idea of natural selection first?
Darwin had the idea first but kept it to himself, but him and Wallace published their theories at about the same time