Midterm Review Flashcards
Morphology – what structures are present in
what group? What do they do?
Structures and functions, mostly apomorphies for the particular groups.
How can groups be differentiated?
Morphology, phylogenetic, group specific apomorphies.
What are diagnostic characters of
species/groups?
Morphology, Genetics, Apomorphies.
What are the main taxonomic groups within
Annelida?
Polychaetes and Clitellates.
Main differences between Cnidaria and
Ctenophora?
Multiciliate cells, gastrulation is invagination or epiboly (not ingression), mouth and anus, muscles in mesoglea (triploblastic?), colloblasts (vs. cnidocytes), apical sense organ, cydippid larva and direct life cycle (no polyp), no asexual reproduction.
What character(s) would you focus on if you are trying to identify a XXX?
Usually should focus on the Apomorphies of the group, and how they differ within the group.
Systems: how do organisms reproduce, breath,
excrete, move, defend, detect etc.
Musculature, Digestion, Internal System, Excretion, Reproduction/Development.
Larval Types
Larval vs. Adult strategies (Ex; medusa and polyp phase)
Habitats – how are organisms adapted to the
environment they live in? – marine,
freshwater, terrestrial
Again, apomorphies are usually important in these questions.
What kinds of larva(e) are found among
Annelid species?
Trochophore larvae that live as plankton. Many species emerge as miniature adults (all Clitellates).
How do Bryozoans reproduce?
Both sexual and asexual reproduction - Asexual by budding off new zooids and by using statoblasts; Sexual by shedding both sperm and eggs into water (since they’re hemaphroditic), or by producing free swimming larvae in brood chambers that eventually leave the colony and settle elsewhere.
Describe the variety of construction strategies
observed in the sponges.
Asconoid - Least advanced
Synconoid -
Leuconoid - Most advanced (and biggest)
If this phylogeny and these tips & traits – how
would you describe X & Y
?
What kinds of feeding modes can be found
among Annelida? How are they different from
each other? How did they evolve from a
putative ancestral mode?
Pharynx and jaws for species that feed on large particulates. Ciliated tentacles or pump water through burrows for filter feeding. Everted pharynx.
Why are some groups so much more diverse
than others?
Due to selection pressures, time since last ancestor, range, ect.
Parasitism
Especially in protozoa and annelids.
Direct versus indirect/Metamorphosis
Direct: When the juvenile phase closely resembles the adult.
Indirect: When the juvenile looks greatly different from the adult.
Sexual/Asexual
Sexual: Uses gametes, usually produced by male and female, but hermaphrodites exist.
Asexual: Fission, budding, fragmentation, or parthenogenesis.
Budding/Regeneration
Budding: A form of asexual reproduction (example: hydra)
Regeneration: Similar to budding, but when a limb is lost, it can be regrown.
Explain the life cycle of XXX
Direct vs. indirect metamorphosis can be important for these questions, as is parasitism.
What is the difference between the XXX and
YYY life cycles?
Again, one could use direct metamorphosis, and one could be indirect. Good example is within the annelids.
