Study Questions for BSC 2011L
Prof. W. Tschinkel
Write a concise essay to answer each question in one page or less.
: Think about your answer before you begin to
1. What is the evidence that arthropods and annelids evolved from a common ancestor?
What evolutionary changes separated the annelids from the arthropods?
Considering the sponges, cnidarians, nematodes, polychaetes and arthropods, how does each solve the problem of skeletal support?
As an object increases in size without changing shape, what happens to the surface/volume ratio? Of what importance is this to animals?
How have animals responded to this problem during evolution?
Using examples from 5 different taxa, describe 5 bodies or body parts
whose structure evolved (at least partly) in response to the surface/volume problem.
Give two examples
from different phyla
of life cycles that display an alternation between sexually and asexually reproducing generations.
Describe the main features of these life cycles.
Are these life cycles homologous to one another?
Defend your answer.
What major changes in body form occurred as the hypothetical ancestral mollusk evolved into the modern mollusk classes?
-like ancestor, briefly describe the changes in the major structural features of the head, axial skeleton and
appendages that have taken place in the evolution of the vertebrate line.
In the phyla Chordata, Arthropoda and Mollusca, there are species that have adapted to terrestrial life.
What major problems did they
overcome in making the transition from aquatic to terrestrial life?
What solutions did they evolve?
Give examples of organisms and
structures throughout your essay.
Draw a hypothetical phylogenetic tree of the animal kingdom, starting with the simplest animals at the bottom. Your branching patterns
should show the correct affinities among acoelomates, coelomates, deuterostomes and protostomes. Include the phyla covered in this
course, except protists. Consider the pseudocoels as one unit.
Compare and contrast the reproductive characteristics (e.g., sexual vs. asexual, monoecious vs dioecious, internal vs external fertilization,
eggs vs. live bearing, larval stages, etc) in Turbellaria, bivalves, Hydrozoa, mammals, oligochaetes, polychaetes, insects, amphibians,
, starfish, and Porifera.
Choose your own set of taxa, and do it again