Final answer:
The phenotypic percentage of normal offspring compared to albinos when two heterozygous parents are crossed is 75% normal and 25% albino, as per Mendelian inheritance principles.
Step-by-step explanation:
The question of phenotypic percentage in the offspring of two heterozygous parents is a classic example of Mendelian inheritance. Albinism is typically caused by a recessive allele. When two heterozygous parents (Aa x Aa) are crossed, the offspring have a 3:1 ratio of normal to albino phenotypes.
Using a Punnett square to predict these outcomes, one would find that there is a 75% chance of an offspring having at least one normal pigment-producing allele (AA or Aa) and a 25% chance of an offspring being albino (aa). Therefore, the correct answer is C) 75% normal, 25% albino.