15.  Which one of the following best describes the product of a gene?

3.  Marine clamworms have flat fleshy appendages used for respiration.  This trait is controlled by a single gene with two alleles.  The alleles display complete dominance/recessiveness.  The dominant allele results in appendages with 3 lobes while the recessive allele results in appendages with 2 lobes. A female worm with 3-lobed appendages mates with a male with 2-lobed appendages.  What is the genotype of the female if some of the offspring have appendages with 2 lobes?

20.  Suppose number of fingers and toes in the North American sasquatch is an X-linked trait represented with the letters A and a.  The dominant allele results in polydactyly, more than 5 fingers on hands and more than 5 toes on feet.  The recessive allele results in “normal” number of fingers and toes, 5 fingers on hands and 5 toes on feet.  Which of the following genotypes would result in a sasquatch with the normal number of fingers and toes?  Select all correct choices.

10.  Red-headedness in humans is due to a recessive allele of the MC1R gene.  Geneticists know that the MC1R gene in humans displays epistasis.  What does this tell you about the expression of the MC1R gene in the phenotype?

6.  Examine the human karyotype below and answer the associated questions.        a.  Does this karyotype indicate a male or a female human?  How do you know?      b.  Name the syndrome associated with the non-disjunction aneuploidy shown in the karyotype.      c.  Which one of the following correctly describes the “source” of this aneuploidy:                Non-disjunction that could only have occurred during oogenesis.                Non-disjunction that could only have occurred during spermatogenesis.                Non-disjunction that could have occurred during oogenesis or occurred during spermatogenesis.

1.  Which one of the following choices correctly diagrams the Central Dogma of Biology?

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17.  Identify each chromosomal designation as indicative of aneuploidy, polyploid, or neither aneuploidy or polyploidy.  The chromosomal designations all apply to the chromosomal complement of human cells.

18.  The diagram below shows spermatogenesis (on the left) and oogenesis (on the right) followed by a fertilization event.  The numbered circles are cells.  The long purple bars in the cells are X chromosomes while the short blue bars in the cells are Y chromosomes.  Cell #8 is the zygote resulting from fertilization.          a.  Where has the non-disjunction occurred?  Use the number to the upper left of the cell to help you explain the location of the non-disjunction.       b.  What non-disjunction syndrome does this illustration demonstrate?  How do you know?

13.  The roseatte spoonbill is a bird that lives in mangrove marshes and captures insects with a long spoon-shaped bill.  Bill color is due to a gene that has two incompletely dominant alleles.  Individuals that are homozygous for one allele have a black bill.  Individuals that are homozygous for the other allele have a bill that is almost white. What color bill will heterozygous individuals most likely express?  Explain the reasoning/rationale behind your answer.