Which of the following phenotypes is an example of polygenic inheritance?

• A. Blood type in humans
• B. Height in humans
• C. Sickle cell anemia
• D. Flower color in pea plants

Answer: (B)

Verified step by step guidance

1. Understand the concept of polygenic inheritance: Polygenic inheritance occurs when multiple genes influence a single trait. This results in a continuous range of possible phenotypes, rather than discrete categories.
2. Identify the traits listed in the problem: The options given are blood type in humans, height in humans, sickle cell anemia, and flower color in pea plants.
3. Analyze each trait: Blood type in humans is determined by a single gene with multiple alleles, making it an example of multiple alleles, not polygenic inheritance. Sickle cell anemia is caused by a mutation in a single gene, making it a monogenic trait. Flower color in pea plants is typically determined by a few genes, often used by Mendel to demonstrate simple Mendelian inheritance.
4. Focus on height in humans: Height is influenced by many genes, each contributing a small amount to the overall phenotype. This results in a wide range of heights in the population, which is characteristic of polygenic inheritance.
5. Conclude that height in humans is the correct example of polygenic inheritance, as it involves the interaction of multiple genes to produce a continuous range of phenotypes.