Question

2b) A black and a white salamander mated and produced offspring with 3 different phenotypes: Black, white and spotted

black and white.
Cross two spotted individuals and give the genotype and phenotype percentages of the offspring.

Answer 1

The offspring of two spotted salamanders with incomplete dominance will have a phenotypic ratio of 25% black, 50% spotted, and 25% white, which reflects a 1:2:1 genotypic ratio.

Step-by-step explanation:

When two spotted salamanders mate, assuming incomplete dominance, the predicted genotype and phenotype percentages of the offspring can be calculated using a Punnett square. If the spotted condition is due to the heterozygous condition (Bb), where 'B' stands for black and 'b' stands for white, and both parents are Bb, the genotypic ratio for their offspring will be:

• 1 BB (black)
• 2 Bb (spotted)
• 1 bb (white)

The phenotypic ratio will be:

• 25% black
• 50% spotted
• 25% white

The phenotypic percentages of the offspring will therefore be 25% black, 50% spotted, and 25% white. This follows Mendel’s laws of inheritance, specifically illustrating a monohybrid cross with incomplete dominance leading to a characteristic 1:2:1 genotypic ratio.