Exam 2 BIO101, Fall 2010 Name: Multiple Choice Questions. Circle the one best answer for each question. (3 points each) 1. All craniates are also classified as A. chordates. B. amniotes. C. vertebrates. D. notocords. E. invertebrates. 2. Which type of organism has a dikaryonic phase of its life cycle? A. Fungi B. Cnidarians C. Protists D. Bryophytes E. Archea 3. The gametophyte stage is dominant in which organisms? A. Bryophytes B. Gymnosperms C. Angiosperms D. s E. Ferns 4. In angiosperms, the male haploid games are produced by the A. carpels. B. pistils. C. anthers. D. sepals. E. stimga. 5. The earliest living organisms were most likely based on which molecule? A. DNA B. Carbohydrates C. RNA D. Lipids E. Protein 6. Two mycelia of different mating types find each other by secreting a substance called a A. pheromone. B. ascus. C. hormone. D. basidium. E. hyphae. 7. Which technique is commonly used to determine the date of a fossil? A. Iridium analysis B. Microscopic assessment C. Oxygenation assay D. Miller-Urey experiment E. Radiometric dating Version A p. 1 of 7 Oct. 27, 2010
8. Endoderm and ectoderm are formed by the process of A. dermination. B. gastrulation. C. plasmogamy. D. vertation. E. blastulation. 9. A spore is different from a seed because spores A. aren t found in plants. B. lack a food supply for the embryo. C. don t have an advanced mechanism for dispersal. D. lack a hardened outside coating. E. have a diploid embryo. 10. The evolution of an animal to a smaller body size when isolated on a small island is called A. island hobbitry. B. remote reversion. C. isolation recession. D. insular dwarfism. E. seclusion-associated deterioration. 11. Bacteria that have a spherical shape are classified as A. cocci. B. Gram-positive. C. bacilli. D. Gram-negative. E. flagellates. 12. Which one group of organisms does not have amniotic eggs? A. Mammals B. Snakes C. Humans D. Frogs E. Birds 13. Tetrapods evolved most recently from what group? A. Echinoderms B. Amniotes C. Jawless fishes D. Molluscs E. Jawed vertebrates 14. A blastula is a developmental stage found in A. seed plants. B. fungi. C. invertebrate animals. D. vertebrate animals. E. all animals. 15. The LB1 specimen is the most-complete and best-preserved example of H. floriensis so it is considered to be the A. archetype. B. primomorph. C. holotype. D. synapomorph. E. quantimorph. Version A p. 2 of 7 Oct. 27, 2010
16. All chordates possess a long flexible rod between their digestive tube and nerve cord at some point in their development. This rod is called the A. neurochord. B. vertebral column. C. cranial string. D. notocord. E. nerve cable. 17. Most eukaryotic organisms don t self-fertilize because A. the resulting heterokaryon is unstable. B. they only produce one type of gamete, either male or female. C. they don t reproduce sexually. D. they are heterosporous. E. self-fertilization doesn t increase the variability that is needed for evolution to occur. 18. Homo floriensis most likely descended from which species? A. Neandertals B. H. erectus C. Modern humans D. A. tigrinum E. Paleolithic humans 19. Which groups of organisms are not vertebrates? A. Sharks B. Hagfishes C. Salamanders D. Lampreys E. Whales 20. Amphibians need to absorb air through their skin because A. they are ectotherms. B. their lungs are inefficient. C. the zygotes develop in water. D. they lack gills. E. they show external fertilization. 21. In class, we discussed that mycorrhizae are in a relationship where two organisms each benefit. (2 points each) 21A. What kind of organisms are mycorrhizae? Fungi 21B. What structure on what type of organisms are closely associated with mycorrhizae? structure: Roots organism: Plants 21C. In this relationship, what benefit does the mycorrhizae receive? They receive food (carbohydrates) from the plant. 21D. In this relationship, what benefit does the other organism receive? The plant receives improved uptake of water and minerals from the soil. Version A p. 3 of 7 Oct. 27, 2010
22. For each statement listed below, circle all the groups for which it is true. (2 points each) These organisms undergo karyogamy. Hemolymph is found in these organisms. This group (or groups) of organisms are each its own domain. These organisms were most similar to the first ancient plants that succeeded at living on land. Chordates are in this group (or groups). This diverse clade (or clades) includes organisms that are photoautotrophic and chemoheterotrophic. These organisms show double fertilization. Cells of these organisms lack nuclei and mitochondria. The Paramecium species that you used in lab last week belong to this group (or groups). These organisms show heterospory. 23. Early plants evolved from having tube-like structures to broad, flat leaves. 23A. What advantage did these plants get by having broad leaves? (3 points) The greater surface area allowed them to be exposed to more sunlight. 23B. What problem does having broad leaves cause? (3 points) The increased surface area-to-volume ratio means that they will lose water more rapidly. 23C. What two important adaptations allowed these early plants to overcome this problem? (4 points) 1. Stomata that could open and close 2. Thicker cuticle Version A p. 4 of 7 Oct. 27, 2010
24. After a mass extinction event, we commonly find a relatively rapid increase in the number of species. Why? (6 points) When many species have died out, there are lots of niches that have opened up and many resources are now available. Therefore, the existing species are able to evolve into new species by the process of adaptive radiation. 25. Higher plants have two types of vascular tissue. What are those two types of vascular tissue and what is moved by each? Why is it advantageous to have two types of vascular tissue and not just one? (8 points) In higher plants, phloem moves sugars and other food and xylem moves water. By having two vascular tissues, the two different substances can move in opposite directions at the same time. 26. Prokaryotic organisms show very high diversity. What features of these organisms allows their rapid evolution, leading to so much diversity? (7 points) Prokaryotes tend to divide very quickly and thus can rapidly achieve very large populations in a short period of time. Since this division is all asexual, this normally wouldn t lead to sufficient variation for the population to evolve. The variability can come from mutations (the populations are large enough that even rare mutations can be found), transformation (the ability to acquire DNA from the external environment) and conjugation (transferring DNA between prokaryotic cells). Version A p. 5 of 7 Oct. 27, 2010
27. Laminaria is a brown algae and one of the more common types of kelp and it s life cycle is diagrammed below. The mature kelp is shown in steps 14 and 15. 27A. Label the sporophyte and gametophyte generations. (4 points) 27B. In the two boxes provided, identify the two processes that happen as the organism transitions between the sporophyte and gametophyte generation. (4 points) Meiosis Sporophyte Gametophyte Fertilization 28. Lynn Margulis proposed that key organelles like mitochondria and chloroplasts are derived from an ancestral prokaryote that was engulfed by a larger cell. 28A. This idea is known as the Endosymbiont Theory. (3 points) 28B. Briefly list three pieces of evidence that support this theory. (6 points) 1. Mitochondria divide by binary fission, like prokaryotes 2. Mitochondria contain their own DNA that is similar to prokaryotes 3. Mitochondria have two membranes Version A p. 6 of 7 Oct. 27, 2010
29. The arthropods are a large and highly successful group of organisms that was among the first animals to successfully colonize land. 29A. Name three different types of organisms that are arthropods. (3 points) Insects Lobsters Spiders 29B. What are the two major challenges that organisms face when moving from water to land? (4 points) Avoiding dessication Structural support 29C. The arthropods evolved a structure composed of chitin which allowed them to overcome both of these challenges. Name this structure and briefly describe how it allows the organisms to overcome the two challenges that you identified. (5 points) An exoskeleton of chitin helps these organisms meet these two challenges. The exoskeleton is relatively thick and fairly impermeable to water, helping the organisms avoid dessication. It is also rigid, giving the organism an overall structure and firm points to attach muscles to. Version A p. 7 of 7 Oct. 27, 2010