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Use a #2 pencil to fill in the information on your NCS answer sheet.
1. Put your O-Key Account Username in the spaces indicated for LAST NAME and darken the corresponding circles.
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Failure to perform this correctly will incur a -10 pt handling fee. Read all questions and answers carefully before choosing the single BEST response for each question. Feel free to ask the instructor for clarification.



In 1958, the Walt Disney Company released a nature documentary called White Wilderness. In it, they claimed that lemmings (small artic rodents) committed mass suicide when their populations grew out of control. Even though it was later revealed that Disney threw the lemmings off a cliff to capture the behavior, large populations really can experience rapid declines in subsequent years. Lemming populations grow exponentially then crash, which is why the populations fluctuate so much.

Leaping Lemmings:


Imagine that a few of the many lemmings thrown off the cliff into the chilly artic waters survived and swam their way to the uninhabited Island of Misfittoyz and began to reproduce. Further investigation showed that those lemmings, and their offspring, had slightly thicker, insulating fur than did those that died.

Another few of the many lemmings were carried by a current to the deserted Trezur Island and immediately formed a breeding population. Among the lemmings that arrived were an unusually high proportion that had a grey streak of fur and curly tails. Many generations later, the population had the same high proportion of individuals with grey streaks of fur and curly tails (many more than the mainland), indicating they had the same fitness as those without the grey streaks and curly tails. The population of lemmings that reached Island of Misfittoyz was 22 and the next year the populations was 44.

Several generations later, Drs. Michael Maus and D. Duc collected lemmings from the islands and bred them with lemmings from the mainland. Here are some of their results.

Lemmings, being mammals, are diploid. The part of the template portion of the gene Drs. Duc and Maus hypothesize as responsible for thick fur is TAC/ATA/CTA/GTT/CAT/ATC and is found on Chromosome 6. They propose that it produces an enzyme, not found in lemmings with thin fur, responsible for adding thickening components into the hair fibers.

Another Lemming:


Dr. Duc was bitten while collecting lemmings in the field and was unable to properly care for the wound, so it became infected, despite Dr. Duc's recent vaccination against tetanus.

Some birds, crustaceans and butterflies have been observed to produce rare individuals that are bilateral gynandromorphs, in which half of the animal is male and half female. An example is the pictured specimen of Papilio glaucus, a common butterfly in eastern North America in which males and females have different color patterns on their wings. In butterflies, females have the sex chromosomes ZW, while males are ZZ (opposite from humans, in which XX = female and XY = male). Sex-linked traits in butterflies thus are on the Z chromosome (Z-linked). Butterfly gynandromorphs apparently result from abnormal egg cells that have two nuclei (each of which is a “normal” egg nucleus); sperm fertilize both nuclei and the fertilized nuclei end up in different cells during subsequent cell divisions in the embryo, resulting in the half-and-half sex. Researchers so far have been unable to get these individuals to lay eggs, so they cannot reproduce.


The European population size decreased rapidly during the bubonic plague outbreak beginning in 1347. Rats carried the plague-infected fleas that would then bite humans (infectious bacterium = Yersinia pestis). Black Death:


Mitochondria inside eukaryotic cells today are theorized to be the results of a two-billion-year-old acquisition of bacteria by some cells.

Endosymbiosis :


Bob (blood type A) and Toni (blood type AB) are the proud parents of Ronnie (blood type B).



A rabbit moves from the shade of a bush to a nearby area in the sunlight, where the ambient temperature is 10 ˚C warmer but still within the thermal neutral zone of the rabbit.



Pat was vaccinated for flu last month and developed flu anyway six weeks later. Perturbed, Pat asked the physician why. Several years later, Pat lost immunity to a strain of the flu.

Flu Vaccination: