Test 7 Review Work PDF

It looks like you have a set of study topics across a variety of subjects related to climate change, viruses, the immune system, and vaccines. Below are the answers to the questions you posed, broken down by topic. Climate Change (Andean Hummingbirds) 1. Response of Andean hummingbirds to clima...

It looks like you have a set of study topics across a variety of subjects related to climate change, viruses, the immune system, and vaccines. Below are the answers to the questions you posed, broken down by topic. Climate Change (Andean Hummingbirds) 1. Response of Andean hummingbirds to climate change: a. Temperature: Andean hummingbirds are likely to respond to climate change through shifts in their altitudinal range. As temperatures increase, they may need to move to higher elevations in search of cooler climates and more suitable habitats. This could lead to changes in migration patterns and breeding behaviors. b. Food availability: Climate change could affect the availability of nectar- producing plants. If flowers bloom earlier or later due to temperature shifts, hummingbirds may struggle to find food, leading to potential declines in populations if their food sources are disrupted. c. Habitat loss: Changes in vegetation at higher altitudes could threaten their habitats, reducing the areas suitable for nesting and feeding. Increased frequency of extreme weather events (e.g., droughts, heavy rain) could also have negative impacts. 2. Which species have higher/lower survival probabilities: a. Higher probability: Species of Andean hummingbirds that are more adaptable to changes in altitude and can take advantage of a wider range of flowers or habitats may have higher chances of survival. Hummingbirds that already occupy higher altitudes may also be better equipped to survive as they move even higher. b. Lower probability: Species with very narrow ecological niches or those dependent on specific types of flowers may be at higher risk. Smaller, less mobile species could be more vulnerable to habitat loss or changes in food availability. Why Are We Still Talking About Geese? 1. Dr. Schul's study of katydids:  a. Dr. Schul studies katydids because their behavior, physiology, or evolutionary traits provide important insights into broader ecological or evolutionary concepts, even if he doesn't have a specific interest in katydids themselves. For example, studying katydids may help understand topics like speciation, communication, or the effects of environmental change on biodiversity. 2. Why are we still talking about geese? a. Geese may be used as a model system in ecological studies due to their migratory behavior, impact on ecosystems, or role in understanding avian physiology. Geese have been used in numerous studies related to environmental change, migration patterns, and the effects of climate on species behavior and distribution. Additionally, geese could be part of a larger discussion about how climate change affects wildlife, particularly those with long migration routes. 3. High altitude breathing unit: a. Molecular level: Changes in the blood's oxygen carrying capacity (e.g., hemoglobin’s role). b. Cellular level: How red blood cells adapt to high-altitude conditions by increasing the number of hemoglobin molecules. c. Organ level: The respiratory system’s adaptation to increased breathing rates in low oxygen environments. d. Organismal level: How humans or animals respond to hypoxia at high altitudes, including increased red blood cell production. e. Population level: How species in high-altitude environments adapt over time (evolutionary changes). f. Community level: How different species (e.g., Andean hummingbirds) share or compete for the same oxygen-rich resources in high-altitude ecosystems. Viral Reproduction 1. Structure of viruses: a. Viruses consist of a core of genetic material (either DNA or RNA), surrounded by a protein coat called a capsid. Some viruses also have a lipid envelope derived from the host cell membrane. 2. Features by which viruses are categorized:  a. Viruses are categorized by their genetic material (DNA or RNA), whether they have a lipid envelope, their shape (helical, icosahedral, complex), and their replication strategy. 3. General steps of viral reproduction: a. Attachment: Virus attaches to a host cell. b. Entry: Virus or its genome enters the host cell. c. Replication and Transcription: Host cell machinery replicates viral genome and transcribes viral RNA. d. Translation: Host cell ribosomes synthesize viral proteins. e. Assembly: New viral particles are assembled. f. Budding or Lysis: New viral particles exit the host cell, either by budding (enveloped viruses) or cell lysis. 4. Features of coronaviruses: a. Coronaviruses are RNA viruses with a positive-sense single-stranded RNA genome, a lipid envelope, and spike proteins that aid in attachment to host cells. SARS-CoV-2 1. Pathways of SARS-CoV-2 entry into cells: a. ACE2 receptor pathway: The spike protein of SARS-CoV-2 binds to the ACE2 receptor on human cells, particularly in the lungs. b. Endocytosis: The virus enters cells via receptor-mediated endocytosis after binding to ACE2. 2. Role of the spike protein in infection: a. The spike protein facilitates viral entry into host cells by binding to the ACE2 receptor on the surface of host cells, especially in the respiratory system. 3. ACE and ACE2 proteins and homeostasis: a. ACE2 normally helps regulate blood pressure and fluid balance by converting angiotensin II into angiotensin 1-7, which has vasodilation effects. SARS-CoV-2 disrupts this balance by binding to ACE2, preventing it from performing its regulatory role. 4. Viral genome: a. SARS-CoV-2’s genome is a single-stranded positive RNA with approximately 30,000 nucleotides. 5. Open Reading Frame (ORF):  a. An Open Reading Frame is a sequence in the viral genome that can be translated into a protein. 6. Structural vs non-structural proteins: a. Structural proteins make up the virus particle (e.g., spike protein, nucleocapsid). b. Non-structural proteins assist in viral replication and evasion of the immune system (e.g., proteases, polymerases). 7. Examples of non-structural protein roles: a. NSP1: Inhibits host mRNA translation. b. NSP3: Helps in replication of the viral genome. 8. Mechanisms of immune evasion by the virus: a. SARS-CoV-2 evades the immune system by suppressing interferon signaling, blocking the host cell’s innate immune responses, and altering the function of immune cells like macrophages and T-cells. 9. Structure of the spike protein: a. The spike protein is a trimeric glycoprotein that binds to the ACE2 receptor on host cells and undergoes conformational changes to facilitate fusion with the host cell membrane. 10. Genetic mutations in variants: a. Mutations in the spike protein can affect its affinity for ACE2, potentially making the virus more transmissible or capable of evading immune recognition. Variants like Delta and Omicron show enhanced infectivity or immune resistance due to mutations in the spike protein. 11. Commonalities between spike protein and hemoglobin: a. Both spike proteins and hemoglobin are involved in binding oxygen-related molecules (in the case of hemoglobin) or receptors (in the case of spike protein and ACE2). Both undergo conformational changes upon binding. Immune System 1. Two parts of the vertebrate immune system: a. Innate immunity: Includes physical barriers, immune cells (e.g., macrophages), and molecules like cytokines that respond quickly to infection. b. Adaptive immunity: Involves T-cells and B-cells, which provide specific immune responses and memory. 2. Acquired immune response steps:  a. Recognition: Antigen presentation to T-cells. b. Activation: T-cells activate B-cells to produce antibodies. c. Effector response: Antibodies neutralize pathogens, and cytotoxic T-cells kill infected cells. d. Memory: Formation of memory cells for quicker responses to future infections. 3. Acquired immune response and long-term immunity: a. Long-term immunity results from memory B-cells and T-cells that recognize pathogens upon subsequent exposure, leading to a faster and stronger response. Vaccines 1. Types of vaccines: a. Live attenuated: Weakened live virus. b. Inactivated: Killed virus. c. Subunit: Part of the virus (e.g., protein). d. mRNA vaccines: Messenger RNA that encodes viral proteins. 2. Clinical testing for vaccines: a. Phase 1: Small group, safety testing. b. Phase 2: Larger group, immune response testing. c. Phase 3: Efficacy in a large population. d. Phase 4: Post-market surveillance. 3. SARS-CoV-2 vaccines: a. mRNA vaccines (e.g., Pfizer, Moderna) use lipid nanoparticles to deliver messenger RNA that encodes the spike protein. This stimulates an immune response without using live virus. b. Differences from past vaccines: mRNA vaccines do not require live virus or adjuvants, unlike traditional vaccines. 4. Mechanism of Covid-19 vaccines and protein synthesis: a. The mRNA vaccines instruct cells to produce the spike protein, which then triggers an immune response. This process involves translation of the mRNA into protein by ribosomes in the host cell. **