Final Exam 1996
Biology 332 - Protistology Final Examination 1996
You will have two and a half hours for this examination. Write all answers in the examination booklet. PUT YOUR NAME ON THE FRONT OF THE EXAM BOOKLET.
120 marks total. Use time wisely (25 mark question = 25 min. writing time).
Here are some words that may help as memory-joggers. They may or may not apply to any of the questions below. amoeboflagellates, bilateria, calcium, channels, chloroplast envelope, choanoflagellates, ciliates, colpodids, conjugation, cysts, diatoms, dinoflagellates, DNA repair, feeding-web, foraminifera, fungi, gamogony, gamontocyst, hymenostomes, hyphae, hypotrichs, immaturity, karyotelicta, macrogametocyte, macronuclear anlage, macronucleus, mastigonemes, meiosis, membrane-potential. meregony, microgametocyte, micronucleus, nucleomorph, oligohymenophora, pawn, pennate, phycobillisomes, placozoa, potassium, pseudopodia, raphé, receptor-potential, radiata, receptors, scales, secondary-symbiosis, senescence, sorocarp, spores, sporogony, starch compartment, suctoria, symbionts.
1. 25 marks. Briefly describe the avoiding reaction in Paramecium, then discuss its physiological basis and control. This behavior pattern has been called "trial and error" behavior. Discuss the extent to which this term is or is not misleading.
2. 20 marks. Answer either a) or b), NOT BOTH.
a) Describe the life history of a ciliate including all stages of the life cycle. What do you know of the role of the nuclei in regulation of the life history. Keep in mind that a life history is more than just the description of the life cycle.
b) Protists show all sorts of adaptations to various environments. This question is about adaptations to benthic (sediment or sediment surface) or terrestrial (soil) environments. Start by making a list of protist groups that have representatives living in 1) benthic and 2) terrestrial environments. Discuss adaptations of the organisms to these environments. What are the major trends (note at least three).
3. 20 marks. Compare and contrast the life cycles of gregarines and coccidia and discuss the life cycles as adapatations to an endozoic habitat. Start by describing the basic reproductive pattern in apicomplexans and discuss how is this pattern has been adapted the two major groups of apicomplexans in response to problems associated with life as an endozoic commensal or parasite.
4. 35 marks. On the next page is a phyletic tree of eukaryotes from an article entitled "The Eukaryotic Kingdoms" by Diane Lipscombe, published in 1985. This tree was based on a cladistic analysis of a large number of morphological traits including many features of flagella and mastigonts (kinetids), cytoskeleton, plastid features, mitochondria etc. This tree was developed prior to the availability of good DNA sequence data.
Write a critique of this tree based on what you know about the phyletic relationships of eukaryotes. Be balanced in your assessments. Consider both placement of groups that you agree with as well as those with which you disagree (Discuss the good, the bad and the ugly). Support your argument with specific detail. Much of your mark will be based on your reasons for agreeing or disagreeing with her positions for groups. You may write your essay in point form where appropriate.
Hints: in assessing this tree it is a good plan to consider the consistency of traits. Consider her title. Is this misrepresentation?
5. 20 marks. Discuss the significant features of cryptomonad organization and evolution. This group has some very peculiar properties and illustrate some very important issues in eukaryote evolution and phylogeny. Among other interesting features they contain 4 different types of rDNA in 4 different cytoplasmic compartments. I am enclosing a chloroplast ss rDNA tree and the 18s rDNA tree from Cavalier-Smith’s 1993 paper. In this tree he refers to cryptomonads as CRYPTISTA and cryptomonadea, (see large asterisks in tree). From the knowledge of this group and from the information contained in these trees what can you tell me about the evolution of these organisms.
