BIOL 100 Exam 2 Flashcards

Evolution and Natural Selection

1. Summarize the cultural and scientific contexts that led to Darwin’s development and publishing of his hypotheses
   
   

   • Darwin’s work was influenced by scientific and cultural changes of the 19th century. His journey on the HMS Beagle exposed him to diverse species and fossils that suggested gradual changes over time. Inspired by geologists like Lyell (who proposed Earth was older than previously thought) and economist Thomas Malthus (who discussed population pressures), Darwin developed "descent with modification", which he later called natural selection (7.1)​.

2. Describe examples of and evidence for evolution by natural selection that can be seen in your daily life
   
   

   • Antibiotic resistance in bacteria (e.g., MRSA) (7.9).

   • Annual flu vaccines due to rapid viral evolution.

   • Artificial selection in domestic animals and crops (selective breeding of plants and livestock) (7.1, 7.9)​.

3. Identify the different kinds of evidence that support the theory of evolution
   
   

   • Fossil record shows species changing over time (7.4).

   • Comparative anatomy (homologous structures).

   • Molecular biology (DNA similarities among species).

   • Direct observation of evolution (e.g., bacterial resistance)​.

4. Explain how the geologic age of fossils can be determined in both relative terms (using layers of rock) and absolute terms (using radiometric dating)
   
   

   • Relative dating: Older fossils are found deeper in sedimentary layers (stratigraphy).

   • Absolute dating: Uses radiometric techniques (e.g., Carbon-14, Uranium dating) (7.4)​.

5. Define macroevolution
   
   

   • Large-scale evolutionary changes over long time spans, including the origin of new species and mass extinctions (7.9)​.

6. Decipher the evolutionary relationships among biological organisms using a phylogenetic tree
   
   

   • Phylogenetic trees show evolutionary connections based on shared characteristics and genetic evidence (7.13)​.

Viruses and Disease

7. Describe the structure of viruses
   
   

   • Genetic material (DNA or RNA) inside a protein coat (capsid). Some viruses have a lipid envelope (8.9)​.

8. Identify the reasons why most biologists do not consider viruses to be alive
   
   

   • Viruses do not grow, reproduce independently, or carry out metabolism. They rely entirely on host cells (8.9)​.

Invasive Species and Community Effects

9. Define invasive species
   
   

   • Non-native species that rapidly spread in a new habitat, often outcompeting native species (12.10)​.

10. Explain the effects that the introduction of an invasive species can have on a community of native organisms
    
    

• Invasive species reduce biodiversity, disrupt ecosystems, and compete for resources.

• Examples: Burmese pythons in Florida, lionfish, zebra mussels (12.10)​.

Immunity and Infectious Diseases

11. Explain why humans continue to get sick despite natural immune systems and modern medicine

• Pathogens evolve via mutation and natural selection, producing new strains that evade immune defenses and treatments​.

12. Define evolution, specifically evolution by means of natural selection

• Evolution: Genetic change over generations.

• Natural selection: Beneficial traits become more common as organisms with those traits survive and reproduce​.

13. Illustrate why antibiotic resistance is more common today than it was in the past

• Overuse of antibiotics selects for resistant bacteria (e.g., MRSA)​.

14. Identify the smallest biological unit that can evolve

• Populations evolve, not individuals (7.6)​.

15. Describe Descent with Modification and explain what it means in modern scientific language

• Over generations, small genetic changes accumulate, leading to new species (7.2)​.

16. Define microevolution

• Small-scale genetic changes within a population over short time spans (7.9)​.

17. Define mutation and identify it as the source of variation within a population

• Mutations are spontaneous changes in DNA, creating genetic diversity​.

18. Identify and discuss different mechanisms of evolution (mutation, migration, genetic drift, natural selection)

• Mutation: Creates variation.

• Migration (Gene Flow): Introduces new genes.

• Genetic Drift: Random changes in small populations.

• Natural Selection: Favors advantageous traits (7.7)​.

Speciation and Evolutionary Biology

19. Describe how the process of natural selection works, and how it results in adaptations

• Individuals with beneficial traits survive longer and reproduce more​.

20. Distinguish between founder effect and genetic bottleneck

• Founder effect: Small population starts a new colony.

• Genetic bottleneck: Large population is drastically reduced (7.7)​.

21. Define a species

• A group that can interbreed and produce fertile offspring (7.10)​.

22. Identify six reproductive barriers that can lead to new species

• Temporal, behavioral, mechanical, gametic, habitat isolation, hybrid weakness​.

23. Recognize the divergence of species through allopatric and sympatric speciation

• Allopatric: Geographic isolation.

• Sympatric: Genetic divergence without isolation (7.11)​.

Prokaryotic vs. Eukaryotic Cells

24. Distinguish between prokaryotic and eukaryotic cells

• Prokaryotes: No nucleus, simple structure.

• Eukaryotes: Have nucleus and organelles (8.2)​.

25. Describe prokaryotic cellular structure and diversity

• Shapes: Cocci (spherical), Bacilli (rod-shaped), Spiral.

• Endospores: Protective shell for harsh conditions​.

Combating Infectious Diseases

26. Describe how we combat infectious diseases (antibiotics and vaccines)

• Antibiotics kill bacteria, but not viruses.

• Vaccines train the immune system to recognize pathogens (8.10)​.

27. Discuss the immune response to infectious diseases

• Innate immunity: External barriers (skin, mucus).

• Adaptive immunity: White blood cells recognize and attack pathogens​.

28. Discuss how various pathogens can lead to sexually transmitted diseases and affect reproductive health

• Bacteria: Chlamydia, gonorrhea.

• Viruses: HIV, HPV, herpes.

• Parasitic STDs: Trichomoniasis.