UNIVERSITY OF KWAZULU-NATAL SCHOOL OF BIOLOGICAL & CONSERVATION SCIENCES (PMB/WVL) EXAMINATIONS: NOVEMBER 2010

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1 UNIVERSITY OF KWAZULU-NATAL SCHOOL OF BIOLOGICAL & CONSERVATION SCIENCES (PMB/WVL) EXAMINATIONS: NOVEMBER 2010 SUBJECT, COURSE & CODE BIOL199 and BIOL099 FOUNDATION BIOLOGY THEORY DURATION 3 HOURS TOTAL MARKS 135 INTERNAL EXAMINERS EXTERNAL EXAMINER K. Brown, B. Keke, N.Kirby, P. Seaman, S. Shaik, J. White Dr. P. Joslin CANDIDATES ARE REQUESTED, IN THEIR OWN INTERESTS, TO WRITE LEGIBLY This paper comprises 13 pages and 1 Appendix (Figure 1). Please ensure you have all the pages. ANSWER ALL QUESTIONS IN YOUR ANSWER BOOKS Section A: Multiple Choice Questions [30 marks] Answer the following questions in your answer book by writing the letter of your choice. 1. Which of the following statements about living organisms is false? A. All can reproduce and maintain a constant internal environment. B. All can grow in cell number. C. The continued survival of their kind depends on their adaptation to the environment. D. All come from a pre-existing individual of their own kind. E. All are descended from a common ancestor. 2. Research has been conducted on the fluctuations in population size of black rhino in Mkhuze game reserve over the past five decades. Which of the following statements is true? A. The independent variable is the size of the rhino population. B. The dependent variable is year. C. The data would be best represented using a pie graph. D. The dependent variable is the number of black rhino individuals. E. Sampling has not been repeated because data collected was only for the black rhino at one game reserve. 3. ALL eukaryote cells: A. have a cell membrane and a cell wall. B. can only be seen using a microscope. C. have plastids of one kind or another. D. have a nucleus at maturity. E. none of the above

2 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page 2 4. Cell membranes: A. compartmentalize metabolic activities. B. freely allow substances to move across the cytoplasm. C. are sometimes folded to decrease the surface area. D. enclose ribosomes. E. all of the above 5. The tissues illustrated below are similar because both are made up of column shaped cells. Which of the following statements is true about these tissues? space in mesophyll lumen/space B A A. The cells in A and B all sit on a basement membrane. B. A and B are both epidermal tissues. C. A and B are both responsible for transport of substances in the air space/ lumen. D. A is chlorenchyma, B is epithelial tissue E. A is pseudostratified epithelium, B is palisade tissue 6. The following are terms used to describe various animal tissues: i. cuboidal ii. brush border iii. fibroblasts iv. pseudostratified v. macrophages vi. collagenous Which combination of terms applies to connective tissue? A. i, ii and iv B. ii, iii and v C. i, iii and iv D. iii, v and vi E. i, iv and vi

3 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page 3 7. This diagram shows a nucleus of a cell. Choose the correct statement about this cell. A. This cell is diploid because the chromosomes are found in homologous pairs. B. The chromosomes are not identical, so this organism reproduces asexually. C. This cell has just completed meiosis I. D. This cell is haploid because the chromosomes are single-stranded. E. This cell has just completed the S - phase of the cell cycle because the chromosomes are found in pairs. 8. Choose the correct statement about this diagram. A. UAC is the start codon. B. The next trna will have the anticodon ATA. C. The anticodon for the third amino acid is UUA. D. The amino acid is being carried by the messenger RNA. E. The trna with the first amino acid is now in the P site of the ribosome. 9. A hermit crab that feeds only on rotting seaweed may be considered: A. a cryptic decomposer. B. a sedentary herbivore. C. an actively mobile detritivore. D. a benthic tertiary consumer. E. a scavenging omnivore. 10. Meristematic tissue: A. is only found in plants. B. is differentiated tissue. C. allows growth. D. allows replacement of dead skin cells in humans. E. C and D 11. Atmospheric carbon is fixed into living biomass by: A. mitochondria. B. ribosomes. C. stomata. D. parenchyma tissue. E. chloroplasts.

4 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page Ferns: A. have true roots, stems and leaves, but no cuticle covering these organs. B. have seeds, but no flowers. C. have a dominant sporophyte generation. D. A and B E. A, B and C 13. Sponges: A. are more ancient than Cnidarians. B. have at least one motile stage in the life cycle. C. have true tissue differentiation. D. A and B E. A, B and C 14. In which order did the following kinds of animals evolve? A. flatworms, molluscs, annelids, arthropods, echinoderms, chordates B. molluscs, flatworms, annelids, arthropods, echinoderms, chordates C. roundworms, flatworms, molluscs, arthropods, chordates, echinoderms D. molluscs, roundworms, flatworms, arthropods, annelids, chordates, echinoderms E. flatworms, molluscs, echinoderms, arthropods, annelids, chordates 15. Which of the following statements is not true of insects? A. They are bilaterally symmetrical, segmented animals. B. They have a true coelom and a complete gut. C. The evolution of complex relationships with flowering plants is always an advantage to the insects. D. Their evolution of a hardened exoskeleton has resulted in dominance on land. E. The mode of life of insect juveniles and adults is often very different. TOTAL FOR SECTION A: 30 MARKS

5 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page 5 Section B: Short Answer Questions Answer all of these questions [90 marks] Question 1 [60 marks] Study Figure 1 (See Appendix), which shows some of the organisms found in a South African marine ecosystem. Then read the text below carefully, and answer the questions that follow: The infratidal region of the east coast of South Africa are sites of great species diversity (Branch, 2002). Common here is a variety of Caulerpa species. For example, Caulerpa filiformis (Organism L) can survive being partially covered by sand because the chloroplasts migrate to the exposed parts of the thallus (undifferentiated, photosynthetic body) (Aitken and Vilakazi, 2000, pg 42). This is because this genus is coenocytic. One kind of sea lettuce, Ulva lactuca (Organism H), can be very abundant in some of these low-shore pools and also across the rest of the inter-tidal region. This species can tolerate wide temperature and salinity changes, and is fed upon by a number of fish species such as Pomacanthus semicirculatus (Day, 2004). Zooplankton such as crab larvae (Organism C) feed on the decaying sea lettuce. The breakdown of this organic matter by other planktonic organisms (e.g. heterotrophic Organism B) benefits the whole ecosystem. Fish species richness is often very high in these pools too (Branch, 2002). Butterfly fish have a variety of striking morphologies. Some are very brightly coloured (e.g. Organism I), some have black and white stripes (Organisms D and F), and others have specialized features that make them well adapted to their environment. For example, Organism K has a distinctive elongated mouth that enables it to probe small holes and crevices for small invertebrate prey. 1.1 a. Organisms C and E are both planktonic. Do they belong to the same Kingdom? Explain in full, by referring to observable diagnostic features, AND to the text above. (4) b. What Phylum does Organism C belong to? Give one reason for your answer. c. Using the dichotomous key below, identify organism D by giving its binomial name. d. By referring to the key, give the name and the letter of the organism that is most closely related to D. Fully explain your answer. (3)

6 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page 6 Dichotomous key: 1. Organism is an animal...2 Organism is not an animal Organism is microscopic...carcinus maenas Organism is not microscopic Organism has bright yellow body Organism does not have bright yellow body Organism has distinctive elongated mouth..forcipiger flavissimus Organism does not have distinctive elongated mouth....chaetodon unimaculatus 5. Organism has black and white striped body markings 6 Organism does not have black and white striped body markings.pomacanthus semicirculatus 6. Organism has very long dorsal fin..heniochus acuminatus Organism does not have very long dorsal fin Chaetodon meyeri 7. Organism multicellular Ulva lactuca Organism not multicellular.8 8. Organism photosynthetic.9 Organism not photosynthetic..amoeba proteus 9. Organism coenocytic Organism not coencytic.. Chlamydomonas meyeri 10. Thallus edges serrated (not smooth)...11 Thallus edges not serrated (smooth)...caulerpa filiformis 11. Thallus edges very finely serrated....caulerpa holmesiana Thallus edges coarsely serrated...caulerpa scalpelliformis 1.2 By referring to the text on the previous page, answer the questions that follow: a. Do you think the rock pools mentioned in the text dry up at low tide? Explain your answer? (1) b. Name the scientist/s who conducted the research into the adaptations of Caulerpa filiformis. (1) c. Explain as fully as possible why Caulerpa filiformis can survive being partially covered by sand. d. By quoting from the text, explain why Ulva lactuca is so abundant along the rocky shores. (3)

7 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page 7 e. Use one term, other than heterotrophic to describe the mode of life of the crab larvae (Organism C). (1) f. The text says that the ecological role of Organism B benefits the whole ecosystem. Explain this statement by referring, in particular, to Organism E. (5) g. What is the fish-species richness of this ecosystem as indicated in Figure 1? (1) h. Find the word in the text that refers to the differences in external appearance of all the fish in Figure 1. (1) 1.3. Which group of organisms is likely to have the larger biomass in this ecosystem: the multicellular autotrophs or the multicellular heterotrophs? Explain your answer. (5) 1.4. a. What theory that can be used to describe how ancestral organisms similar to E may have given rise to multicellularity. (1) b. In terms of evolutionary trends, describe the relationship between Organisms B, C and D. (3) c. The development of jaws was a significant step in the evolution of the diversity of fish and other marine organisms we see today. Explain this statement. (5) 1.5 During the evolution of the symmetry shown by fish there was selection of sensory structures and nerve cells in the head region. a. Give the term that refers to the concentration of sensory structures in the head region. (1) b. Of what importance was the concentration of sensory structures in a head end during the evolution of this symmetry? (3) 1.6 Fish reproduce sexually. Populations that reproduce sexually have a lot of genetic variability and so there is a good chance that some individuals will survive when environmental conditions change. a. Describe and explain the role of meiosis in sexual reproduction. Do NOT describe the process of meiosis. (6) b. Name two events in meiosis that result in genetic variation. c. Explain the term adaptation. d. By referring to the role of genetic variation in natural selection and adaptation, explain how Organism K has evolved to be so well adapted to life in its environment. (6) 60 marks

8 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page 8 Question 2 Study Figure 2 below and answer the questions that follow. 1 [15 marks] X 2 C 8..found free in the 9.. A 3 Y template or complementary strand? or 5 end? 7..strand Figure What process is occurring in Figure 2? (1) 2.2 In your answer book, provide labels for numbers 1 to 10 to complete Figure 2. (5) 2.3 Name the enzyme working at point 4. Describe the role of this enzyme. 2.4 Name the enzyme working at point 5. (1)

9 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page Consider sequence labeled X-Y and the genetic code in Table 1 below. If this sequence of units was to be copied into messenger RNA, what amino acid sequence would be produced in the following stage? Show how you came to this conclusion. (4) 2.6 Explain the importance of the process occurring in Figure 2 to growth in cell number. 15 marks Table 1: The genetic code

10 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page 10 Question 3 [15 marks] Study Figure 3 and answer the questions that follow. E Ancestral Charophyceae cones D C B A Archeosperma arnoldii Rhynia major No protection for the Figure 3 developing embryo 3.1 a. Compare Organism D with the other organisms in Figure 3. b. Provide a label for E. (1) c. Mosses are the most well known extant representative of ancestral organisms like E. What does extant mean? (1) d. Mosses are restricted to living in moist habitats. Explain why a. What is the most recent common ancestor of C and A? (1) b. What two main features did this organism have that allowed colonization of land? Explain your answer. (3) a. What is the phylum name of A? (1) b. Describe and explain, by referring to their features, why this group of plants has become the most dominant and diverse of this Kingdom. You should include a comparison with B in your answer. (4) 15 marks TOTAL FOR SECTION B: 90 MARKS

11 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page 11 Section C: Mini essay questions [15 marks] Answer only ONE (1) question in this section. You should write about 1-1½ pages for your Mini-essay. OPTION 1 Prokaryotic organisms dominated the planet for the first 1.5 billion years of life on Earth. These early prokaryotes were heterotrophic. The subsequent evolution of autotrophic prokaryotes had dramatic consequences for the conditions on ancient Earth, and influenced the course of evolution of every organism on the planet from that point forward. Discuss this statement. Be sure to include the following: A description of how autotrophic prokaryotes changed the conditions on Earth An explanation of how eukaryotes are different to prokaryotes and how eukaryotes are said to have evolved from prokaryotes A description of the consequences of the evolution of eukaryotes. Marks Introduction Have you used this section to provide a relevant background and 3 introduce the topic i.e. have you described what prokaryotes are, have you compared heterotrophic and autotrophic organisms? Content (Body) 1. Have you described how the autotrophic prokaryotes changed the 3 conditions on ancient Earth? 2. Have you explained the consequences of these changed conditions by: a. describing what eukaryotes are, and how they are said to have evolved 4 from prokaryotes. b. describing the consequence of the evolution of eukaryote organisms. 3 Conclusion 1 Have you used this section to summarize your main points? General Have you written coherently, and is the content relevant to the topic? 1 15

12 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page 12 OPTION 2 The fossilized remains of an ancient tree species were discovered on the north west coast of Africa and on the south east coast of North America. The paleontologist who made this discovery could find no evidence that these plants produced flowers when they were alive, but he did find fossilized seeds. Using this information and carbon dating, he concluded that the fossils were of the same species that existed in the Permian, about 250 million years ago. Write a mini-essay in which you: Discuss what fossilization is, Explain how these organisms became fossils, Explain why it is possible for the same fossilized species to be found in different continents and Suggest, giving reasons, what kind of plant, the fossils were of. Marks Introduction Have you used this section to provide a relevant background and 3 introduce the topic i.e. have you described what fossilization is? Content (Body) 1. Have you explained how the organisms became fossils? 4 2. Have you explained reasons for the same fossilized organism to be 3 found in different continents? 3. Have you suggested what kind of plant the fossils were of, and 3 explained the reasons for your choice. Conclusion 1 Have you used this section to summarize your main points? General Have you written coherently, and is the content relevant to the topic? 1 15

13 COURSE & CODE: BIOL099 and 199 Foundation Biology Theory Page 13 OPTION 3 The function of a tissue is determined by its structure. Discuss this statement by referring to 1 (one) example of plant and animal tissue that you have studied. Marks Introduction Have you used this section to provide a relevant background and 3 introduce the topic i.e. have you described what a tissue is and referred to the structure- function relationship? Content (Body) 1. Have you described one animal tissue and explained how its 5 structure relates to how it functions? 2. Have you described one plant tissue and explained how its 5 structure relates to how it functions? Conclusion 1 Have you used this section to summarize your main points? General Have you written coherently, and is the content relevant to the topic? 1 15 TOTAL OF SECTION C: 15 MARKS

14 A. Mag: x 0.2 dorsal fin D. Mag: x 0.38 flagellum nucleus B. Mag: x 123 Bright yellow body P C mm chitinous body covering Q cellulose cell wall E. Mag: x 1250 chloroplast dorsal fin F. Mag: x 0.35 nucleus I. Mag: x 0.4 K. Mag: x 0.5 L Mag: x 0.6 Coenocytic thallus Coenocytic Multicellular thallus thallus J Figure 1. Example of part of a South African marine ecosystem (not drawn to scale) 4 cm H. Mag: x 0.35 G 5 mm

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