5.2 Inheritance

Punnett Square Genetic Breeder

Perform genetic breeding crosses. Match dominant and recessive parent alleles (BB, Bb, bb) to compute homozygous/heterozygous phenotype offspring percentages.

Virtual Viewport
Monohybrid Cross
×
B
b
B
BBTall
BbTall
b
BbTall
bbDwarf
Genotype Ratio
BB
1/4 (25%)
Bb
2/4 (50%)
bb
1/4 (25%)
Phenotype Ratio
Dominant (Tall)
3
Recessive (Dwarf)
1
3 : 1
Offspring Sample
BB
Bb
Bb
bb

Active Sliders

genOffspring Sample50qty
10100

Mock population size generated for ratios.

Syllabus Objectives

  • Define dominant, recessive, genotype, phenotype, homozygous, and heterozygous
  • Construct Punnett squares for monohybrid genetic crosses
  • Calculate probability ratios of offspring phenotypes and genotypes.

Mathematical Equations

Genotype Ratio (Bb x Bb)
1 \, BB : 2 \, Bb : 1 \, bb
Phenotype Ratio (Bb x Bb)
3 \, Dominant : 1 \, Recessive

Inquiry Guide Sheet

1

Cross two heterozygous parents (Bb × Bb). Verify the classic 3:1 phenotype ratio (75% dominant, 25% recessive).

2

Cross a homozygous dominant (BB) with a homozygous recessive (bb). Observe the offspring genotypes.

3

Explain why recessive traits can remain hidden for generations and then reappear.