Core Concepts in Biology: Evolution, Classification, and Life Forms

Posted on Aug 19, 2025 in Biology

Evolutionary Biology Fundamentals

1. The original source of all genetic variation is: Mutation
2. Microevolution occurs when: Changes in allele frequencies in a population occur over generations.
3. What is the only evolutionary mechanism that consistently leads to adaptive evolution? Natural selection.
4. The evolutionary effects of genetic drift are greatest when: The population size is small.
5. Which of the following descriptions illustrates phenotypic variation caused by the environment? Diet of caterpillars changes their morphology.
6. Blue poppies native to China were grown at a plant-breeding center in California. The plants with..… This adaptation of the poppies to their new environment is due to: Directional selection.
7. Who created the binomial classification system that we still use today? Carolus Linnaeus.
8. Inheritance of acquired characteristics was proposed by: Jean-Baptiste Lamarck.
9. In humans, the tailbone, wisdom teeth, and goosebumps are all examples of: Vestigial traits.
10. Darwin and Wallace’s theory of evolution by natural selection was revolutionary because it: Dismissed the idea that species are constant and emphasized the importance of variation and change in populations.
11. An adaptation is: A trait that gives an organism a reproductive advantage in the current environment.
12. Which of the following statements describes the effect of evolution on a population? Increasingly better match between a population and its environment.
13. Varieties of Staphylococcus aureus that are resistant to the drug methicillin: Already existed in the population before methicillin was developed.

Speciation and Macroevolution

14. Hardy-Weinberg Genotype Frequency Calculation:
    If p = C^R = 0.8 and q = C^W = 0.2, the frequency of genotypes can be calculated as follows:
    • C^RC^R = p² = 0.8 × 0.8 = 0.64
    • C^RC^W = 2pq = 2 × 0.8 × 0.2 = 0.32
    • C^WC^W = q² = 0.2 × 0.2 = 0.04
15. Which of these is an example of temporal isolation? One species is nocturnal, and the other species is not.
16. If biological species are defined in terms of reproductive compatibility, the formation of a new species hinges on: Reproductive isolation.
17. Two species of frogs belonging to the same genus occasionally mate, but the embryos stop developing after a day and then die. These two frog species are separated by: Reduced hybrid viability.
18. The production of sterile mules by interbreeding between female horses (mares) and male donkeys (jacks) is an example of: Reduced hybrid fertility.
19. Which of the following is the first step in allopatric speciation? Geographic isolation.
20. Sympatric speciation is: The appearance of a new species in the same area as the parent population.
21. Which of these animals could overcome the geographic barrier of water that causes allopatric speciation? Small rodents.
22. According to the _____ model, evolution occurs in spurts; species evolve relatively rapidly then remain unchanged for long periods: Punctuated equilibrium.
23. Which postzygotic barriers prevent the formation of hybrids beyond the first generations? Hybrid breakdown.
24. Miller and Urey’s experiments that attempted to recreate conditions on early Earth were significant because: They showed that organic molecules such as amino acids could be produced from inorganic molecules.
25. The first genetic material on Earth was probably: Self-replicating RNA molecules.
26. What is the most accurate method used to measure the age of a fossil? Radiometric dating.
27. Which of the following showed their greatest diversity during the Mesozoic Era, but were a small, less diverse group during the Paleozoic Era? Gymnosperms.
28. Upon being formed, oceanic islands, such as the Hawaiian Islands, should feature what characteristic, leading to which phenomenon? A variety of empty ecological niches, leading to adaptive radiation.

Taxonomy and Phylogenetics

29. Which branch of biology is concerned with the naming and classifying of organisms? Taxonomy.
30. Animals that possess homologous structures probably: Evolved from the same ancestor.
31. Some beetles and flies have antler-like structures on their heads, much like male deer. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of: Convergent evolution.
32. Which of the following taxonomic categories contains all the others listed here? Class.
33. By definition, a clade is: Monophyletic.
34. In a comparison of birds and mammals, having four limbs is: A shared ancestral character.
35. Which of the following are the three domains currently used for classification? Bacteria, Archaea, Eukarya.
36. The scientific name of the giant swallowtail is Heraclides cresphontes. Therefore, it belongs to the genus: Heraclides.
37. In cladistics, ________ is (are) the primary criterion used to classify organisms: Shared, derived characters.
38. A(n) ________ is one that is present in the common ancestor and the outgroup: Shared ancestral character.

Prokaryotic Life Forms

39. What is the function of fimbriae? They are used to attach the cell to its substrate or to other prokaryotes.
40. Genes for the resistance of antibiotics are usually located: On plasmids.
41. Which of the following is LEAST associated with the others? Binary fission.
42. Which statement is true about obligate anaerobes? They are poisoned by O₂.
43. The prokaryotic organisms most likely to be found living in salt ponds are the: Halophiles.
44. An ecological relationship between organisms of different species that are in direct contact can best be described as: Symbiotic.
45. Bioremediation is: The use of organisms to remove pollutants from the environment.
46. Which of the following structures does a prokaryote not have? Nucleus.
47. Prokaryotes reproduce asexually by: Binary fission.
48. Which of the following domains consists of all the organisms whose cells have true nuclei? Eukarya.

Diversity of Protists

49. Trypanosome infections evade attacks by host immune systems through which of the following mechanisms? Production of new cell-surface proteins with a different molecular structure by each new generation.
50. Which of the following approaches would be most likely to cause the evolution of a drug-resistant strain of Plasmodium? Widespread, frequent use of a single drug in patients suffering from malaria.
51. Archaeplastids, which include red and green algae and land plants, are thought to have descended from a heterotrophic protist that engulfed a(n): Cyanobacterium.
52. All protists are: Eukaryotic.

Plant Kingdom Diversity

53. When a mosquito infected with Plasmodium first bites a human, the Plasmodium _____ cells infect the human liver cells: Sporozoite.
54. A porous test (shell) of calcium carbonate, through which pseudopodia protrude, is characteristic of: Foraminiferans.
55. Which of the following groups is matched with a correct anatomical feature? Brown algae → blade.
56. _____ are eukaryotic autotrophs that float near the surface of water and are the basis of the food chain: Phytoplankton.
57. The closest algal relatives of land plants are: Charophytes.
58. Which of these events, based on plant fossils, came last (most recently)? Rise and diversification of angiosperms.
59. Which taxon is essentially equivalent to the “embryophytes”? Plantae.
60. Apical meristems: Occur in both roots and shoots of plants.
61. Which of these are spore-producing structures? Sporophyte (capsule) of a moss.
62. The evolution of a vascular system in plants allowed which of the following to occur? Increased height, improved competition for light, and increased spore dispersal distances.
63. When you look at a pine or maple tree, the plant you see is a: Diploid sporophyte.
64. The advantages of seeds, compared to spores, include: Containing a nutrient store for a developing sporophyte.
65. Gymnosperms were most abundant during the: Mesozoic Era.
66. Angiosperms are different from all other plants because only they have: Flowers.