Quiz: Basic Genetics
Part I: Multiple Choice. Put the letter which you think best completes the item on the line.
_____1. The gene make-up of an organism for a particular trait is its
a/ genotype c/ dominance
b/ phenotype d/ allele
_____2. The appearance of an organism is it
a/ allele c/ phenotype
b/ dominance d/ genotype
_____3. Each parent contributes one form of the gene for a particular trait. Whether or
not the genes are exactly alike, the genes of the pair are called
a/ variables c/ alleles
b/ hybrids d/ gametes
_____4. If 75% of the offspring from experimental crosses showed the dominant
character, and 25% showed the recessive trait, the parents were probably
a/ both pure dominant c/ one pure dominant, one recessive
b/ both heterozygous d/ one heterozygous, one pure dominant
_____5. The phenotypes of homozygous black guinea pigs and heterozygous black
guinea pigs are
a/ BB or Bb
d/ 50 % black, 50% white
Part II. Genetic problem Solving
1. Of the following genotypes, indicate which are homozygous and which are
Gg HH Mm gg
NN Ll jj oO
2. A rare blue flowered plant was accidentally pollinated by pollen from a white colored
plant of the same species. All of the offspring were white flowered.
a. What color was dominant? What color was recessive?
b. What was the genotype of the offspring?
c. Construct a Punett square and explain how you could produce a blue colored
plant from the white flowered plants of the offspring.
3. For pea plants, tall (T) is dominant over short (t). Mendel crossed two tall pea
plants that were both heterozygous.
a. What is the chance that the offspring will be tall?
b. What is the chance that the offspring will be short?
c. What is the chance that the offspring will be heterozygous?
4. In humans, brown (B) eye color is dominant over blue (b) eye color. A female who
has brown eyes and is homozygous, marries a male who has blue eyes. They have
three boys, each of which has brown eyes.
a. Construct a family pedigree and tell the phenotypes and genotypes of each
b. If one of the sons marries a woman who is heterozygous for brown eyes, what
is the chance that they would have a blue eyed child?
c. Show a Punnett Square to explain your reasoning.