Given the following are the statements about quantitative inheritancea)Quantitative inheritance results in a range of measurable phenotypes of a polygenic trait.b)Polygenic traits often demonstrate continuous variation.c)Certain alleles of quantitative trait loci (QTL) have an additive effect on the character/trait.d)Alleles governing quantitative traits do not segregate and assort independentlyCorrect answer is option 'A,B,C'. Can you explain this answer?

Question

Answer

Quantitative Inheritance

a) Quantitative inheritance results in a range of measurable phenotypes of a polygenic trait.
Quantitative inheritance refers to the inheritance of traits that are controlled by multiple genes. These traits are known as polygenic traits. Unlike Mendelian traits, which are controlled by a single gene, polygenic traits demonstrate a wide range of phenotypes or observable characteristics. For example, height, weight, and skin color are polygenic traits that can vary continuously within a population.

b) Polygenic traits often demonstrate continuous variation.
Polygenic traits exhibit a continuous range of variation rather than distinct categories. This continuous variation is due to the cumulative effect of multiple genes and their alleles. Each allele contributes incrementally to the phenotype, resulting in a wide spectrum of possible trait values. For example, in the case of height, individuals can range from very short to very tall, with many intermediate heights in between.

c) Certain alleles of quantitative trait loci (QTL) have an additive effect on the character/trait.
Quantitative trait loci (QTL) are specific genomic regions that are associated with the variation of a polygenic trait. These regions contain alleles that contribute to the phenotype of the trait. In the case of quantitative inheritance, certain alleles at QTL have an additive effect on the character or trait. This means that each additional copy of the allele contributes to an incremental increase or decrease in the trait value. For example, if a specific QTL is associated with height, individuals carrying more copies of the allele associated with taller height will generally be taller than those with fewer copies.

d) Alleles governing quantitative traits do not segregate and assort independently.
This statement is incorrect. Alleles governing quantitative traits do segregate and assort independently during the process of meiosis, just like alleles for Mendelian traits. The independent assortment of alleles allows for the creation of new combinations in the offspring, leading to the continuous variation observed in polygenic traits.

Therefore, the correct statements about quantitative inheritance are:
- Quantitative inheritance results in a range of measurable phenotypes of a polygenic trait.
- Polygenic traits often demonstrate continuous variation.
- Certain alleles of quantitative trait loci (QTL) have an additive effect on the character/trait.

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