Biology 227, Fall 2020.
Final Exam Description and Short Answer Questions
Exam Overview
The Biology 227 Theory Exam will be on Moodle, in time period scheduled by
Examinations, that is, Tuesday December 15th, 9am – 12pm. This exam will be in 2 parts.
First, there will be approximately 50 multiple choice questions (1 mark each),
divided evenly between the 10 tutorials (~ 5 per tutorial). To prepare for this, try the multiplechoice questions in the assigned chapters of Campbell Canadian 2. Review the weekly
Moodle sections for the readings and look at the clicker questions and consider likely
question scenarios.
Second, there are 13 short answer questions below. You will be assigned 1 of these
13 questions randomly in the exam and it will be worth up to 10 marks.
Each question has a similar structure, first a headlining question that focuses your
attention on the subject and then two or three parts that ask you to develop specific answers.
The marks for each part total 10 marks.
Answer each part of your question in a in a full paragraph (i.e. 2 or 3 paragraphs per
question). Do not write in point form. Pay attention to the marks in each part as a guide to
structuring your answer. Marks will be assigned for correct answers, incorrect will reduce the
sum of points. There is a word limit that once exceeded will also reduce the sum of points
(400 words). Finally, your logic, organization and clarity also figure into your mark.
If you prepare answers to these questions in advance, you should be able to download
them into the allocated space during your exam - a time saving measure if you are prepared. You
have a little less than 2 weeks to prepare answers to these questions, and they are intended to
review the course of study in Biol 227.
Short- Answer Questions
1) Both Classification and Cladistics begin with measuring species character similarities,
most simply, classifying them as similar or different. Assuming they use the same similarity
measurements, then how do they differ?
a) Briefly describe how Linnean taxonomy organizes more and less similar species into
taxonomic categories and determines relationships between taxa (3 points).
b) Briefly describe how key Cladistic relationships species relationships differ from a
Linnean-type taxonomy. (3 points).
c) In what ways could Cladistics be a more ‘natural ‘taxonomy. (4 points)
2) Why did it take 2 billion years for multicellular eukaryotes to become frequent enough to
be detected in a fossil record and diverse enough to be interesting?
a) Describe what we know of organism diversity in the Archaean Eon and the
significance of this period change in Earths’ history. (3 points)
b) List the key environmental and organism changes in the Proterozoic Eon, using ‘Early,
‘Middle’ and ‘Late‘ Proterozoic for reference. (4 points)
c) Having reviewed environmental and organism diversification for 2 billion years in the
Proterozoic in a & b, what do you think promoted multicellular animal and plant
diversification during the Cambrian Period? (3 points)
Biology 227, Fall 2020.
Final Exam Description and Short Answer Questions
3) The technology we have worked with in the lab exercises is a highly refined mechanical
and optical tool, the microscope.
a) Discuss why we insist you label the magnification in a figure caption (4 marks).
b) Why is the microscope such a valuable tool when studying organism diversity, even
though you cannot visualize large multicellular organisms like most Land Plants and
Vertebrates. (6marks)?
4) There are 2 approaches to characterizing bacteria: 1) growth in an enrichment culture and
eventually a Petrie dish and; 2) an environmental sample that is processed for the diversity of
a genetic sequence in a sample. Why might you choose use one method or the other?
a) Briefly review the shortcomings and advantages of the enrichment culture and Petrie
plate method. (3 points)
b) Briefly review the shortcomings and advantages of the environmental sample methods. (3
points)
c) Compare both methods to answer under what circumstances and for which reasons you
would use each method. (4 points)
5) Sexual reproduction in haploid fungi display key characters that allow us to uniquely
classify most fungal phyla.
a) In your first paragraph briefly describe the key differences abetween sexually
reproducing Fungi phyla. (4 marks).
b) In your second paragraph, focus on those life history stages which are not haploid
(dikaryons and diploids). Describe the differences in the diploid or dikaryotic stage
among fungi that have sex. (3 marks).
c) Finally, hypothesize what might be the causes or constraints that could be driving this
evolutionary trend (if any), remembering that a hypothesis is an informed idea. In
other words, speculate on an evolutionary trend (or not), using dikaryotic and diploid facts
you reviewed above and fossil evidence or molecular phylogenies. (3 marks).
6) J. H Ma (2017) and others have written that it is not possible to tell whether sponges are
degenerate Eumetazoans or as consensus phylogenies indicate, sponges share common
ancestors with basal Metazoans.
a) What characters do sponges and radiates like Hydra have in common, that is
putatively ancestral characters. (3 marks)
b) Why are radiates like Hydra thought to be derived from Metazoans like Calcareous
sponges? (4 marks)
c) Describe a scenario where a Radiate evolves into a Metazoan sponge. (3 marks).
7) An unqualified or idealized coelom could be ancestral, alternatively a derived and/or
diversified character among Bilaterians. Explore this through the following questions.
a) Briefly describe the origin of coelom space. (3 marks)
b) What is the evidence and the reasoning that the coelom is an ancestral character
among Bilaterians? (3 marks)
c) In what way do Ecdysozoans and Chordates exemplify how this early developing
character may diversify? (4 marks)?
Biology 227, Fall 2020.
Final Exam Description and Short Answer Questions
8) Review the influence of mass extinctions on animal diversification.
a) First, in one paragraph define the key geological periods in animal diversification
associated with large-scale changes in diversity (3 marks).
b) In the next paragraph, briefly describe any associations between mass extinctions and
key geological periods, using several examples from Biol 227 (4 marks).
c) In your final paragraph discuss the role of mass extinctions have had in animal or
plant diversification, focusing on key environmental changes and their consequences.
(3 marks)
9) Why is homology a unifying concept in studies on organism diversity? Explore this
question by considering the evolution of the Mollusc foot and the Chordate notochord
a) First, define homology .(2 marks)
b) Using your definition show how it applies to the diversification of the Mollusc foot
across Mollusc Classes .(4 marks)
c) Using your definition, show how it applies to diversification of the chordate notochord
among Chordate classes. (4 marks)
10) Where can you find meristematic tissue in mature eudicot plants with secondary growth?
a) Where is meristematic tissue in roots with primary and lateral roots? (4 marks)
b) Where is meristematic tissue in stems with primary and secondary growth? (4 marks)
c) Where is meristematic tissue in branches and leaves? (2 marks)
11) Alternation of generations is a land plant innovation, although i) some algae have this
kind of life cycle and the gametophyte stage is extremely reduced in Angiosperms. Review
the evolution of land plant alternation of generations by answering the following.
a) The immediate algal ancestors of land plants probably had what kind of life history?
Briefly explain how this changed in the transition to land. (3 marks)
b) Explain in detail the key events in a haplo-diplontic life cycle with sporic meiosis or
alternation of generations. (4 marks)
c) Generally, how is the gametophyte stage reduced in clades with more recent common
ancestors than Bryophytes? (3 marks)
12) Monocots, Rosids and Asterids are all recently- evolving, extremely diverse and
successful taxa comprising the vast majority of Angiosperm species. Use the lecture and lab
material to make plausible suggestions about the causes of evolutionary success among these
3 taxa.
a) Monocots (4 marks)
b) Rosids (3 marks)
c) Asterids (3 marks)
13) Explain the form and function of photosystem II and its relation to the surrounding
thylakoid membranes, inter-membrane and stroma space.
a) Briefly describe the location, form and function of photosystem II (4 marks) in a
chloroplast.
b) What is the relationship between photosystem II and the attached thykaloid
membranes? (3 marks)
c) What is the relation between Photosystem II and the space on both sides of the
membrane it is embedded within? (3 marks).
Biology 227, Fall 2020.
Final Exam Description and Short Answer Questions