Ch 44-45 Articles Guided Questions
Extrarenal Salt Excretion in Birds
1. How do marine mammals obtain fresh water in their diets?
a. In their regular foods/diets.
2. According to this study why is it hard to study whether oceanic birds use sea water?
a. The fish they eat have low water concentrations and even lower salt concentrations.
3. What was the species chosen for this study?
a. Phalacrocorax aurilus aurilus (double-crested cormorants)
4. What were the IV and DV of the experiment ?
a. IV: what they fed the birds (fish/sea water)
b. DV: rates of cloacal electrolyte elimination (for Cl, Na, K) in g/min
5. What were the major findings of this study?
a. No evidence to support the hypothesis that sea birds must drink sea water in order to
cover their normal needs for water.
Balancing Selection at the Prion Protein
1. What is a prion?
a. Infectious agent composed of protein in a misfolded form.
2. What is Kuru?
a. Acquired prion disease largely restricted to the Fore linguistic group (of the Papua
New Guinea Highlands, which was transmitted during endo-cannibalistic feasts.)
3. In what populations is it found?
a. Eastern Highlands of Papua New Guinea Highlands.
4. How is it transmitted?
a. Inoculation of chimpanzees with autopsy-derived brain tissue.
5. What is PRNP?
a. Human prion protein gene 6. What does the protein-only hypothesis states?
a. The central molecular event in prion replication is the posttranslational recruitment of a
normal neuronal glycoprotein (PrPC) into a self-propagating conformational isomer that
accumulates as aggregated material (PrPSc)
Human Evolution: A legacy of cannibalism
1. How are DNA sequences variants established in human populations?
a. Result of migration, selection and random genetic drift operating, as a function of the
effective population size, on human populations over the last million years.
2. What is CJD?
a. Creutzfeld-Jakob Disease
3. How are the genotypes of individuals affected with this disease?
a. At the prion protein locus, there is a polymorphism for alleles that encode either
methionine or valine at codon 129 (M129V) of the polypeptide product. All vCJD-