Bio 305 Test #2 Review Spring 2018
Chapter 5- Comparative Embryology (5.1, 5.2, 161-176, 190-192)
Gastrulation and Neurulation in chicken embryo
Same basic events, but altered sequence (heterochrony) and elaboration
epiblast and hypoblast
primitive streak, Henson’s node/Primitive node, neural tube
formation of gut
Function of extra-embryonic membranes in cleidoic egg
allantois, amnion, chorion
Mammal’s “use” of the extraembryonic membranes to form placenta
Chorioallantoic membrane fuses to uterus
General overview- Variations in vertebrate embryology
Yolkamt, direct/indirect dev, aquatic/terrestrial, long/short dev, cleidoic,...
Medullary bone and egg production/calcium mobilization in birds
Calcium homeostasis, osteoclasts, osteoblasts (182
calcitonin, PTH, inhibition, stimulation, feedback,…
Ch 4- Evolutionary potential of developmental mutations/body plan genes (128-137)
Evolutionary constraints
Evolutionary “innovations” must be integrated into the whole organism.
Certain combinations of traits cannot occur.
Evolution of bigger body size and Allometric Laws/Scaling Laws
biophysical/architectural requirements
Body Size and Limb Width
Body Size and Metabolic Weight (Kleiber’s Law)
scapula size and body size in quadrupeds vs. bipeds
vertebra size and body size in quadrupeds vs. bipeds
wing surface area and body size in birds
Body size, metabolic rate, guttoral pouches, “exceptions” to law
Chapter 6- Integument (212-232)
What are the shared features of the integument in all vertebrates?
Derived from ectoderm & mesoderm
Ectodermal components: epidermis (strata corneum & basale)
Mesodermal components: dermis (strata laxum & compactum)- Collagen fibers
What are the relative contributions of ectoderm and dermis to the skin?
Morphological variations in skin anatomy are related to its function(s)
How does the skin function for organisms in different classes?
What are the derivatives of skin? Scales, teeth, dermal bones, feathers, hair, claws, nails, hooves, antlers,…..What is the relative contribution of epidermis and dermis to each of these derivatives?
Phylogenetic overview (thickness of layers, glands, chromatophores, derivatives,…)
Fish (Chondrichthyes and Osteichthyes)
How can scale type be used to construct a phylogeny for the fishes?
Placoderms give rise to chondrichthyes
Acanthodians give rise to actinopterygians and sarcopterygians
Actinopterygians give rise to osteichthyes
Sarcopterygians give rise to lungfish, coelocanths, and tetrapods
In the groups above, which have the following scale types?
Placoid, cosmoid, ganoid, cycloid, ctenoid
How do scale types vary with respect to epidermal/dermal contributions?
Tetrapods (Amphibians, Reptiles, Birds and Mammals)
Compare skin of primitive amphibians and advanced amphibians
How does amphibian skin compare to fish skin?
How is reptile skin different from amphibian skin?
Sloughing (multiple generations of epidermis, fission zones,…)
How are feathers produced?
Flight feathers, downy feathers, barbs, barbules,…
Why is there so little variation within the Class Aves?
How is mammal skin unique? How is hair produced?
Antlers vs. horns