Mendel's Laws

Question 1

In the monohybrid cross of Mendel, when a pure round-seeded plant was crossed with a wrinkled-seeded plant, all the F1 progeny were round-seeded, because of:

• ACo-dominance
• BIncomplete dominance
• CComplete dominance
• DEpistasis

Question 2

In a cross of AaBb x AaBb, what fraction of the offspring can be expected to express one of the two dominant alleles, but not both?

• A1/16
• B6/16
• C9/16
• D16/16

Question 3

In which of these cases can two genes experience independent assortment?

• AThey are located in close proximity on the same chromosome.
• BCrossing over between the genes does not occur.
• CThey are located on different chromosomes or are far apart on the same chromosome.
• DThe expression of one gene does not affect the expression of the other.

Question 4

In pea plants, the allele for tall stalks (T) is dominant over short stalks (t). A cross between a tall plant and a short plant produces 43 tall and 47 short offspring. If one tall offspring is crossed with one short offspring, what genotype ratio is most likely?

• A1 TT : 2 Tt : 1 tt
• B3 Tt : 1 tt
• CAll Tt
• D1 Tt : 1 tt

Question 5

Allele B produces black coat colour while b produces white. Allele C produces curly fur while c produces straight fur. In a cross between two BbCc parents, what fraction of offspring have black coat and straight fur?

• A3/16
• B9/16
• C3/4
• D16/16