COVID-19
What are the five key components that make up the genetic material of a virus?
Spike glycoprotein - proteins involved in the invasion and infection of a host cell.
RNA and N protein - RNA is a nucleic acid that delivers instructions from DNA for the synthesis of proteins, and an N protein is a protein that encloses the RNA.
Who simultaneously came to the ideas of evolution by natural selection?
Charles Darwin and Thomas Malthus
How did polymers potentially form in an abiotic world?
Small organic molecules polymerize when they are concentrated on hot sand, clay or rock. This is important, as life arose from the first organic compounds on earth.
During what era did dinosaurs originate, and during what era did they go extinct?
Dinosaurs originated, lived through, and went extinct in the Mesozoic era.
What can happen if a spike protein undergoes a mutation?
If a spike protein undergoes a mutation, the T-lymphocytes in our immune system may fail to recognize the virus, and the protein will be able to invade and infect a host cell.
Define: Evolution, fitness, adaptation
Fitness: reproductive success of an individual
Adaptation: heritable change that becomes common or pervasive in a population or species because it increases fitness
What idea about the origin of life did the skepticism around the Miller-Urey experiment lead to instead?
Although they were able to produce organic molecules from inorganic matter, their theory that the atmosphere was responsible for the formation of earth's first organic material is under skepticism because earth's early atmosphere is not thought to have been that strong of a reducing agent. It is thought that instead, earth's first organic compounds, from which life first arose, were synthesized near volcanoes and deep-sea vents, where carbon compounds are found in higher quantities. It is also thought that some of the organic compounds from which life first arose came from space, as meteorites found on earth contain high levels of carbon.
During what era did mammals originate?
Mammals originated during the Mesozoic era; small mammals coexisted with dinosaurs for over 100 million years, but it is thought that mammals originated during the Cenozoic era.
How do spike proteins interact with host cells, and how does our immune system interact with/respond to spike proteins?
Spike proteins of the virus bind to receptors on the host cell that they are invading and initiate the infection of the host cell. The T-lymphocytes in our immune system recognize spike proteins they have encountered before and the B-lymphocytes produce antibodies to attack the spike proteins before the virus can spread.
What is the difference between homology and convergence?
Homology is the similarity in traits between organisms due to a common ancestor. Convergence is the similarity of that have adapted to similar environments but have evolved independently from common ancestors.
What is a ribozyme and what is it an example of?
A ribozyme is an RNA enzyme that acts as a catalyst to catalyze chemical reactions, and it is an example of a protobiont.
What major features of life evolved during the Precambrian era?
prokaryotic cells, bacteria, the process of photosynthesis (for example; blue-green cyanobacteria), sexual reproduction between organisms such as bacteria, eukaryotic cells (such as protists), and multicellular organisms (such as volvox, a multicellular protist)
What do s and Ro (Rnot) stand for in sRo, and what does the variable sRo itself represent?
Ro = expected number of infections with an entirely susceptible population (no one is vaccinated or previously infected)
s = proportion of population that is susceptible (unvaccinated/ not previously infected individuals)
sRo = reproduction rate of virus
What is necessary for evolution by natural selection to operate?
More individuals of a species are reproduced than the environment can support, so individuals with traits that increase their fitness (ability to survive in the environment) will produce more offspring, and this leads to a gradual change in population with more favorable traits accumulating.
What are protobionts and what are their significance?
Protobionts are collections of organic molecules surrounded by membranes, and they are significant because early forms of protobionts had catalytic, self-replicating RNA that were capable of variation and mutation, increasing the likelihood of evolution through natural selection.
What is the most likely reason for the extinction of many large mammals about 12,000 years ago.
It is thought that human arrival and hunting is the most likely reason for the pleistocene extinction. Extinction on other continents also correlate with human arrival, so this hypothesis is highly likely.
How can we interpret Ro and sRo to determine how we can lead to the decline of COVID-19?
sRo must be less than 1, which happens when s is less than 1/Ro.
In the HIV evolution example, were mutations caused by antiviral drug use? Did the antiviral drug select for resistant forms of the virus?
Mutations were not caused by antiviral drug use; the mutations occurred by chance but the drug selected for pathogens that are resistant to the drug's effects because of chance mutations. The antiviral drugs select for resistant forms of the virus.
Why is it more likely than RNA was the first genetic material to evolve rather than DNA?
RNA molecules contain ribozymes, which act as catalysts and form new copies of parts of RNA. DNA replication requires many complex enzymes, so it is likely that RNA molecules had the ability to self-replicate and were the first genetic material to evolve.
What was the Cambrian explosion and what was its significance?
The Cambrian explosion occurred at the end of the Precambrian era and at the beginning of the Paleozoic era. It is significant because many different animal forms evolved quite suddenly, likely due to key innovations amongst species like jaws and jointed appendages that could have led to rapid interactions among species and co-evolution.