Based on the pedigree above, what is the most likely mode of inheritance of this disorder?

In mice, coat color is determined by two genes:

• Gene A determines pigment color:

• A = agouti (banded hairs)
• a = black (solid color)

• Gene B controls pigment deposition:

  • B = pigment deposited
  • b = no pigment (albino)

If a mouse is homozygous recessive (bb), it will be albino regardless of the alleles at gene A.

Two heterozygous mice with genotype AaBb are crossed.

What is the expected phenotypic ratio of their offspring?

In a species of flowering plant, two genes—Gene X and Gene Y exist. Both genes encode similar transcription factors involved in leaf development. Researchers create single mutants for each gene (xx and yy) and a double mutant (xx yy).

They observe the following:

• YYxx i.e. x mutant: Normal leaf development
• yyXX i.e. y mutant: Normal leaf development
• yyxx double mutant: Abnormal leaf development

What is the most likely explanation for the observed phenotypes?