The genes for the traits that Mendel worked with are either all located on different chromosomes or behave as if they were. How did this help Mendel recognize the principle of independent assortment?
a. Otherwise, his dihybrid crosses would not have produced a 9 : 3 : 3 : 1 ratio of F2 phenotypes.
b. The occurrence of individuals with unexpected phenotypes led him to the discovery of recombination.
c. It led him to the realization that the behavior of chromosomes during meiosis explained his results.
d. It meant that the alleles involved were either dominant or recessive, which gave 3 : 1 ratios in the F1 generation.

The alleles found in haploid organisms cannot be dominant or recessive. Why?

a. Dominance and recessiveness describe which of two possible phenotypes are exhibited when two different alleles occur in the same individual.

b. Because only one allele is present, alleles in haploid organisms are always dominant.

c. Alleles in haploid individuals are transmitted like mitochondrial DNA or chloroplast DNA.

d. Most haploid individuals are bacteria, and bacterial genetics is completely different from eukaryotic genetics.

Two black female mice are crossed with a brown male. In several litters, female I produced 9 black offspring and 7 brown; female II produced 57 black offspring. What deductions can you make about the inheritance of black and brown coat color in mice? What are the genotypes of the parents?

Why is the pea wrinkle-seed allele a recessive allele?

a. It 'recedes' in the F2 generation when homozygous parents are crossed.

b. The trait associated with the allele is not exhibited in heterozygotes.

c. Individuals with the allele have lower fitness than that of individuals with the dominant allele.

d. The allele is less common than the dominant allele. (The wrinkled allele is a rare mutant.)