Introduction: Evolution and the Foundations of Biology 1 Introduction: Evolution and the Foundations of Biology Questions prepared by Brad Stith, University of Colorado Denver Janet Lanza, University of Arkansas at Little Rock Louise Paquin, McDaniel College

1. Which of the following is not a theme that unifies biology? systems biology emergent properties inductive reasoning reductionism genomics Answer: D

2. What is the correct order (from small to large)? cells, organelles, organ system, community, ecosystems molecules, organism, population, communities, biosphere molecules, cells, tissues, ecosystems, communities organelles, cells, population, biosphere, ecosystems cells, organs, population, ecosystems, communities Answer: B 3

3. Which of the following scientific studies would represent an example of a “systems biology” approach? measuring the effect of an invading insect that eats oak leaves on the numbers of oak trees and on any subsequent changes in the number and types of decomposer fungi in the soil discovering the structure of an enzyme that is important in digestion of protein comparing the microscopic structure of leaves of two different species of magnolias measuring the reproductive rate of emperor penguins during exceptionally warm and exceptionally cold years comparing the DNA sequence of two closely related plants and inferring their evolutionary histories Answer: A In the past, most research has been conducted on one or two levels of complexity (e.g., cells or population levels). Recently, however, scientists or teams of scientists have been studying how processes at one level affect processes on other scales. This question is designed to help students see connections among levels. Answers C–E address scientific questions at only one level: C is a study at the tissue level, D is a study at the population level, and E is a study at the molecular level. Answer B is likely a study simply at the molecular level, but a student might argue that it addresses two levels—molecular and cellular. It could certainly be expanded to a systems study if the scientists also studied molecular forces and folding of the protein chain. Answer A is likely the best answer because the two-species interaction between the invading insect and the oak (community level) affects the abundance of oak trees (population level) and the process of decomposition (ecosystem level). A possible extension of this question would be to ask students to broaden all the answers into systems biology studies. 4

The original source of the energy was the sun. 4. Like jackrabbits, elephants have many blood vessels in their ears that help them cool their bodies by radiating heat. Which of the following statements about this radiated energy would be accurate? The original source of the energy was the sun. The energy will be recycled through the ecosystem. The radiated energy will be trapped by predators of the elephants. More energy is radiated in cold conditions than in hot conditions. More energy is radiated at night than during the day. Answer: A Energy is a concept that is essential for all students to understand. This question will help students understand a number of ideas about energy. Answer A is the correct answer; students should understand that the energy from the sun powers all living systems (except deep-ocean vent communities). Energy is lost to the system as heat, whereas atoms can be used over and over again; thus, answer B is incorrect. Answer C is related to answer B and is incorrect because the heat that is radiated from the ears is not available to other organisms—only the energy stored in the tissues of the jackrabbit is available to the predator. Answers D and E are incorrect for the same reason—that more heat is radiated when the jackrabbit is warmer (either in hot conditions or during the day). 5

Plants that live in dry areas have large roots for absorbing water. 5. The idea that form and function are related would not be exemplified by which of the following examples? Cells in the intestinal lining of vertebrates have many small projections that increase the surface area for absorption of nutrients. Plants that live in dry areas have large roots for absorbing water. Seeds that are dispersed by wind are very light. Fish that swim rapidly have bodies that are streamlined. none of the above Answer: E The relationship between form and function is very important and results from the action of natural selection. In this question, all answers show a relationship between form and function, and therefore none of them connects correctly to the stem. 6

It is probably closely related to pond algae. 6. Imagine that you have just discovered a new multicellular but microscopic organism that swims in ponds. You see that it is propelled by cilia on the outside of the organism. What can you say about the evolutionary relationships of this organism? The presence of cilia shows that it is more closely related to Paramecium than to humans. The presence of cilia shows that it shares a common ancestor with Paramecium and humans. It is probably closely related to pond algae. It is probably most closely related to prokaryotes. The presence of cilia demonstrates the diversity, but not the unity, of life. Answer: B It can seem contradictory to students that “evolution can account for both the unity and diversity of life,” but this is an important concept for them to understand. Organisms share traits that they have inherited from a common ancestor (the unity of life) but differ in traits if natural selection, or perhaps genetic drift, leads to change (the diversity of life). Cilia occur in both Paramecium and humans and, most notably, have the same internal structure. This pattern shows that they have a common ancestor (i.e., answer B is correct), but the differences between Paramecium and humans show that they have diverged over evolutionary time. The mere presence of cilia cannot help us decide what the new organism is closely related to (either Paramecium as in answer A, pond algae as in answer C, or prokaryotes as in answer D). Answer E is incorrect because the presence of cilia shows the unity, not the diversity, of life. 7

No such predictions are possible. 7. Examine the figure on the next slide and predict which species pair has the most similar DNA sequence. vegetarian tree finch (Platyspiza crassirostris) and mangrove finch (Cactospiza heliobates) medium tree finch (Camarhynchus pauper) and large tree finch (Camarhynchus psittacula) large tree finch (Camarhynchus psittacula) and small tree finch (Camarhynchus parvulus) sharp-beaked ground finch (Geospiza difficilis) and large ground finch (Geospiza magnirostris) No such predictions are possible. Answer: C The goal of this question is to make students actually look at the “family tree”—it’s very easy to just glance at it and think you understand it. Of the choices given, only answer C gives two species that are each other’s closest relative, e.g., “sister species.” 8

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Science is typically performed alone in the lab. 8. Which of the following is an activity that would not reflect the practice of science? Science is typically performed alone in the lab. Data are typically collected by teams of students and experienced researchers. Scientists typically reexamine conclusions or repeat experiments from other large, famous labs. Scientists who work in forests studying ecology often collaborate closely with geneticists who work only in the lab. The practice of science results in a discovery that lends new insight, and technology involves how this new insight will be applied to develop a new drug. Answer: A 10

9. State the difference between systematics and taxonomy; describe the importance of each. List the levels of taxonomic classification from most inclusive to least inclusive.