In mice, black coat color is dominant to white coat color. In the pedigree shown here, mice with a black coat are represented by darkened symbols, and those with white coats are shown as open symbols. Using allele symbols B and b, determine the genotypes for each mouse. 

Verified step by step guidance

1. Identify the dominant and recessive alleles: Black coat color is dominant (B) and white coat color is recessive (b). Therefore, mice with black coats can have genotypes BB or Bb, while white-coated mice must be bb.
2. Examine the pedigree symbols: Darkened symbols represent black-coated mice, and open symbols represent white-coated mice. Assign the genotype bb to all white-coated (open) mice since they must be homozygous recessive.
3. Analyze the parents and offspring relationships: For each mating pair, use the phenotypes of their offspring to infer the parents' genotypes. For example, if two black-coated mice have a white-coated offspring, both parents must be heterozygous (Bb) to pass on the recessive allele b.
4. Use Mendelian inheritance rules: Recall that offspring receive one allele from each parent. Use Punnett squares or probability to determine possible genotypes of each mouse based on their phenotype and the genotypes of their relatives.
5. Assign genotypes to all mice in the pedigree: Starting from known genotypes (white mice as bb), work through the pedigree step-by-step, deducing the genotype of each black-coated mouse as either BB or Bb based on the presence or absence of white offspring and the genotypes of their mates.

Key Concepts

Dominant and Recessive Alleles

Dominant alleles express their trait even if only one copy is present, while recessive alleles require two copies to show their trait. In this case, black coat color (B) is dominant over white coat color (b), meaning mice with BB or Bb genotypes have black coats, and only bb mice have white coats.

Genotype vs. Phenotype

Phenotype refers to the observable traits, such as coat color, while genotype is the genetic makeup that determines these traits. Understanding the difference helps in deducing the genotype of each mouse based on their phenotype and inheritance patterns.

Pedigree Analysis

A pedigree chart tracks the inheritance of traits across generations. By analyzing the pattern of black and white coat colors in the pedigree, one can infer the possible genotypes of each mouse using principles of Mendelian inheritance.