The astronaut looked out the porthole. Where a yellow orb should've hung was blackness. A voice crackled through the speaker: "Sorry, but we've made an error. . . rather trivial, actually. But instead of landing on the moon, I'm afraid you are headed for Pluto. We want to assure you, however, that we here at Ground Control do understand the principles of navigation."

Alas, your understanding of genetics principles must be demonstrated on your General Purpose Answer Sheet, form no. -16504. Please be sure not to mark on the question sheets, but to mark your answers on the form only. Each question is worth four points. All recessive alleles are underlined. Good Luck.

The correct answer for each question is denoted by the blinking characters.
If your browser cannot detect the blinking characters, check the answer table at the bottom of this test.

1. The planet Peebles is inhabited by creatures called Peeblesians, which may be bearded (B__) or non-bearded (bb), and blonde-haired (G__) or green-haired (gg) . Two Peeblesians, a bearded, green-haired male and a non-bearded blonde female, have been brought to the Galactic Zoo, where you are in charge of breeding. The two Peeblesians are successfully crossed, and all members of the litter have beards and blonde hair.

   1. If two littermates are crossed, what will be the phenotypic ratio from that cross:
      1. 2 : 1 : 1
      2. 1 : 1 : 1 : 1
      3. 9 : 3 : 3 : 1
      4. 3 : 1
      5. 4 : 2 : 2 : 2 : 2 : 1 : 1 : 1 : 1

   2. Astronauts bring back a non-bearded, green-haired male Peeblesian. If this Peeblesian is crossed with a female member of the litter from the previous question, what will be the resulting phenotypic ratio?
      1. 2 : 1 : 1
      2. 1 : 1 : 1 : 1
      3. 9 : 3 : 3 : 1
      4. 3 : 1
      5. 4 : 2 : 2 : 2 : 2 : 1 : 1 : 1 : 1

   3. Peeblesians may also be right-handed (R __) or left-handed (rr). If two bearded, blonde-haired, right-handed Peeblesians, who are completely heterozygous for all three genes, are crossed, what will be the resulting phenotypic ratio?
      1. 27 : 9 : 9 : 9 : 3 : 3 : 3 : 1
      2. 4 : 2 : 2 : 2 : 2 : 1 : 1 : 1 : 1
      3. 9 : 3 : 3 : 1
      4. 1 : 1 : 1 : 1 : 1 : 1 : 1 : 1
      5. (l : 2 : l)³

   4. If two bearded, blonde-haired, right-handed peeblesians, who are completely heterozygous for all three genes, are crossed, how many different genotypes are possible in the offspring?
      1. 4
      2. 8
      3. 9
      4. 27
      5. 64

2. 5. Principle of Independent Assortment
      1. Either allele of one gene pair enters a gamete with either allele of any other gene pair.
      2. Alleles of each gene separate during gamete formation and enter different gametes, so that half the gametes carry one allele and half carry the other.
      3. All possible combinations of alleles are produced in equal proportions.
      4. Mendel's First Law.
      5. More than one of the above.

3. 6. The science of Genetics was born when Br. Gregor Mendel's work was discovered simultaneously by the three scientists in:
      1. 1687
      2. 1866
      3. 1900
      4. 1953
      5. 1994

   7. The genus and species of the organism in which Gregor Mendel studied seven contrasting traits was:
      1. Homo sapiens
      2. Pisum sativum
      3. Drosophila melanogaster
      4. Jimus cheanevus
      5. Gallus domesticus

4. A testcross involving an F₁ parent results in a testcross progeny phenotypic ratio of 1 : 1 : 1 : 1 : 1 : 1 : 1 : 1
   

   8. If two F₁ individuals were crossed to produce an F₂ generation, how many different phenotypes could be present in the F₂ generation?
      1. 64
      2. 27
      3. 8
      4. 4
      5. Billions and billions

   9. What fraction of the gametes produced by the F₁ individuals would be completely recessive for the gene (or all the genes) in question?
      1. 1/8
      2. 1/4
      3. 1/3
      4. 1/2
      5. My dog ate my calculator

5. You have a pet, a duck-billed platypus, with the following genotype:
   AA Bb cc Dd Ee FF gg Hh Ii JJ

   10. How many heterozygous allele pairs would be involved if this platypus were to be used in an F₁ breeding experiment?
       1. 42
       2. 10
       3. 5
       4. 3
       5. 1

   11. If this F₁ platypus were to be testcrossed, how many different phenotypes could be observed in the testcross progeny?
       1. 59,049
       2. 1,024
       3. 243
       4. 32
       5. Roughly equivalent to the national debt

   12. How many different F₂ genotypes of baby platypi could be produced if two F₁ individuals were crossed?
       1. infinity
       2. 1,048,576
       3. 59,049
       4. 243
       5. 3

6. Two homozygous strains of corn are hybridized. They are distinguished by two different pairs of genes, all of which assort independently and produce an independent phenotypic effect. The F₁ hybrid is selfed to give an F₂.

   13. How many of the total possible different genotypes in the F₂ will be homozygous at both gene loci?
       1. 5
       2. 4
       3. 3
       4. 2
       5. 1

   14. If all gene pairs act in a dominant-recessive fashion, what proportion of the F₂ will show all recessive phenotypes?
       1. 0
       2. 1/2
       3. 1/4
       4. 1/8
       5. 1/16

7. P __ = Polled; pp = horned; RR = Red; RR' = Roan; R'R'= White
   A white bull heterozygous for polled is mated to roan females heterozygous for polled. Remember polled is dominant to horned.

   15. What is the genotypic ratio of the offspring?
       1. 3 : 1
       2. 9 : 3 : 3 : 1
       3. 3 : 3 : 1 : 1
       4. 2 : 2 : 1 : 1 : 1 : 1
       5. 2 : 1 : 1

   16. What is the phenotypic ratio of the offspring?
       1. 9 : 3 : 3 : 1
       2. 2 : 2 : 1 : 1 : 1 : 1
       3. 3 : 1
       4. 2 : 1 : 1
       5. 3 : 3 : 1 : 1

8. 17. In peas, tall (D) is dominant to dwarf (d), Yellow (G) is dominant to green (g), and Round (W) is dominant to wrinkled (w). What fraction of the offspring from the following cross would be heterozygous in all gene pairs?
       GgDdww X GgddWw
       Gene pairs are on separate chromosomes and there is no gene interaction.
       1. 1/64
       2. 1/32
       3. 1/16
       4. 1/8
       5. 1/4

   18. Given the following cross, how many different genotypes could be produced among the offspring?
       Aa Bb Cc DD Ee X Aa bb Cc dd Ee
       1. 243
       2. 81
       3. 27
       4. 8
       5. None of the above

   19. If all gene pairs were heterozygous in the above cross, how many different genotypes could be produced among the offspring?
       1. 8
       2. 27
       3. 81
       4. 243
       5. None of the above

9. Two complementary genes work together to produce the comb shape in chickens: R__P__ = walnut
   R__pp = rose
   rrP__ = pea
   rrpp = single

   20. A homozygous dominant walnut-combed rooster is mated with a single-combed hen. One of the resulting pullets grows into a hen which is crossed with a heterozygous pea-combed rooster (rrPp). What will be the phenotypic ratio resulting from this second cross?
       1. 1 : 1 : 1 : 1
       2. 3 : 3 : 1 : 1
       3. 1 : 1
       4. 9 : 3 : 3 : 1
       5. 3 : 1

10. Consider the following genetically controlled biosynthetic pathway in a hypothetical plant:

    	allele A		allele B
    	enzyme A		enzyme B
    white		orange		maroon

    Assume that orange pigment is coded for in the presence of the dominant allele A, but the plant remains white in its absence; and the dominant allele B, but not the recessive allele b, codes for the enzyme necessary to catalyze the conversion of the orange pigment to a maroon pigment.

    21. What phenotypes and proportions can be expected in the progeny of the AaBb x aaBb cross?
        1. 4 white : 3 maroon : l orange
        2. 4 maroon : 3 orange : l white
        3. 9 orange : 7 white
        4. 12 maroon : 3 orange : l white
        5. 9 maroon : 4 white : 3 orange

    22. The following phenotypic ratio would be approximated in the F₂ from a mating between two maroon F₁ individuals:
        1. 9 : 3 : 3 : 1
        2. 12 : 3 : 1
        3. 13 : 3
        4. 9 : 4 : 3
        5. 9 : 7

    23. The specific type of epistatic gene interaction involved would be:
        1. dominant and recessive
        2. dominant
        3. duplicate recessive
        4. recessive
        5. duplicate dominant

11. In sesame, both the number of seed pods per leaf axil and the shape of the leaf are genetically controlled. The one-pod (P) condition is dominant to the three-pod (p) condition, and normal leaf (W) is dominant to wrinkled leaf (w). The two characters are inherited independently and there is no gene interaction between the gene pairs. Recessive alleles are underlined.

    24. A 1-pod, normal plant was crossed with a 1-pod, wrinkled plant and the following progeny were produced:

        110 1-pod, normal : 113 1-pod, wrinkled : 33 3-pod, normal : 38 3-pod, wrinkled

        The genotypes of the plants crossed would be:

        1. Pp ww X pp Ww
        2. Pp Ww X pp Ww
        3. PP Ww X pp Ww
        4. Pp WW X pp ww
        5. Pp Ww X Pp ww

    25. A 1-pod, normal plant was crossed with a 3-pod, normal plant and the following progeny were produced:

        303 1-pod, normal : 95 1-pod, wrinkled : 297 3-pod, normal : 105 3-pod, wrinkled

        The genotypes of the plants crossed would be:

        1. Pp Ww X Pp ww
        2. Pp WW X DD ww
        3. Pp Ww X pp Ww
        4. Pp ww X pp Ww
        5. PP Ww X pp Ww

---

Correct Answers for this Test (question # -- answer)

1 -- C	6 -- C	11 -- D	16 -- E	21 -- A
2 -- B	7 -- B	12 -- D	17 -- D	22 -- D
3 -- A	8 -- C	13 -- B	18 -- E	23 -- D
4 -- D	9 -- A	14 -- E	19 -- D	24 -- E
5 -- E	10 -- C	15 -- D	20 -- B	25 -- C

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