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Ch. 25 - Quantitative Genetics and Multifactorial Traits
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All textbooksKlug 12th EditionCh. 25 - Quantitative Genetics and Multifactorial TraitsProblem 1

Chapter 24, Problem 1

How do we know that threshold traits are actually polygenic even though they may have as few as two discrete phenotypic classes?

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Hey everyone, let's take a look at this question together. Which of the following statements is true about threshold traits being poly genic. So let's recall what we've learned about threshold traits. To try to figure out which of the following statements is true. So when we talk about threshold traits, we're talking about discontinuous variation and the term polly genic poly meaning multiple genic, meaning genes is involved with multiple jeans, meaning that threshold traits have multiple genes and experience discontinuous variation. So answer choice A. Is incorrect because they are not controlled by a single gene and answer choice B. Is incorrect because they exhibit discontinuous variation. So that leaves us with answer choice C. And D. Which we know answer choice D. Is incorrect because the threshold traits are not only expressed in the presence of a specific environmental factor because these threshold traits are controlled by multiple genes and environmental factors have an influence on them. So answer choice C. Is the correct answer. And is the only true statement about threshold traits listed here. I hope you found this video to be helpful. Thank you and goodbye.
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Textbook Question

In this chapter, we focused on a mode of inheritance referred to as quantitative genetics, as well as many of the statistical parameters utilized to study quantitative traits. Along the way, we found opportunities to consider the methods and reasoning by which geneticists acquired much of their understanding of quantitative genetics. From the explanations given in the chapter, what answers would you propose to the following fundamental questions:

How do we know that monozygotic twins are not identical genotypically as adults?

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In this chapter, we focused on a mode of inheritance referred to as quantitative genetics, as well as many of the statistical parameters utilized to study quantitative traits. Along the way, we found opportunities to consider the methods and reasoning by which geneticists acquired much of their understanding of quantitative genetics. From the explanations given in the chapter, what answers would you propose to the following fundamental questions:

How do we assess environmental factors to determine if they impact the phenotype of a quantitatively inherited trait?

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Textbook Question

In this chapter, we focused on a mode of inheritance referred to as quantitative genetics, as well as many of the statistical parameters utilized to study quantitative traits. Along the way, we found opportunities to consider the methods and reasoning by which geneticists acquired much of their understanding of quantitative genetics. From the explanations given in the chapter, what answers would you propose to the following fundamental questions:

What findings led geneticists to postulate the multiple-factor hypothesis that invoked the idea of additive alleles to explain inheritance patterns?

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How can we ascertain the number of polygenes involved in the inheritance of a quantitative trait?

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