NEET Biology Genetics : Polygenic Inheritance does not follow Mendelian Ratio

TL;DR

Polygenic inheritance and Mendelian inheritance differ in the number of gene pairs involved and the resulting phenotypic ratios, with polygenic inheritance exhibiting multiple intermediate phenotypes.

Transcript

hello friends this video on need genetics is brought to you by exams your calm no more fear from exam now by now we understood the difference between polygenic inheritance and monogenic inheritance now polygenic inheritance does not follow the maintain Ian ratio and that is why posit any inheritance does not really follow the medallion pattern of i... Read More

Key Insights

• 🥺 Polygenic inheritance involves multiple gene pairs, leading to intermediate phenotypes, while Mendelian inheritance involves two gene pairs with distinct dominant and recessive traits.
• 🥳 In Mendelian inheritance, the phenotypic ratio follows a specific pattern, while polygenic inheritance exhibits more genetic diversity and does not follow the Mendelian pattern.
• #️⃣ The number of phenotypes in polygenic inheritance is greater than in Mendelian inheritance, reflecting the contribution of multiple gene pairs.
• 😪 Polygenic inheritance can result in a wider range of variations in traits, as seen in the multiple shades of red in the example of wheat kernels.
• 🚱 The presence of dominant alleles in polygenic inheritance contributes to the overall trait, while non-contributing alleles do not affect the phenotype.
• ❓ Polygenic inheritance provides more genetic possibilities and contributes to the overall genetic diversity in a population.
• 🖐️ Polygenic inheritance plays a significant role in complex traits such as height, skin color, and intelligence.

Questions & Answers

Q: What is the main difference between polygenic inheritance and Mendelian inheritance?

The main difference is the number of gene pairs involved. Mendelian inheritance involves two gene pairs, while polygenic inheritance involves multiple gene pairs.

Q: How does the phenotypic ratio differ between polygenic inheritance and Mendelian inheritance?

In Mendelian inheritance, the phenotypic ratio follows a specific pattern, while in polygenic inheritance, the phenotypic ratio includes multiple intermediate phenotypes.

Q: What is an example of Mendelian inheritance?

An example is the cross of brown and yellow pea seeds, which results in round and yellow phenotypes in the F1 generation and a phenotypic ratio of 9:3:3:1 in the F2 generation.

Q: Can you provide an example of polygenic inheritance?

An example is the cross of pure red and pure white wheat kernels, which results in multiple intermediate shades of red in the F1 generation and a phenotypic ratio of 1:4:6:4:1 in the F2 generation.

Summary & Key Takeaways

• Mendelian inheritance with two gene pairs involves dominant and recessive traits, leading to a specific phenotypic ratio in offspring.

• Polygenic inheritance involves multiple gene pairs, resulting in intermediate phenotypes and a different phenotypic ratio.

• Polygenic inheritance does not follow the Mendelian pattern and exhibits more genetic diversity.