BIO207H5S Introductory Genetics Lecture 17: Quantitative Traits

Play an AI-generated podcast conversation about this lesson

What term is used to describe traits that result from both gene action and environmental influences?

Monohybrid traits

Multifactorial traits (correct)

Incomplete dominance traits

Polygenic traits

In the Nilsson-Ehle experiment, what was the observed grain color in the F1 generation when red grain wheat was crossed with white grain wheat?

White

Red

Purple

Pink (correct)

Why did the observations in the F2 generation of the Nilsson-Ehle experiment not follow the typical monohybrid cross segregation ratio (1:2:1)?

Incomplete dominance at multiple loci

Polygenic inheritance (correct)

Random chance

Environmental influences

Which environmental factors can affect plant height, as mentioned in the text?

Sunlight, humidity, and nutrients Signup and view all the answers

What term describes the concept that alleles at multiple loci contribute to the range of phenotypes seen in quantitative traits?

Polygenic inheritance Signup and view all the answers

How would you characterize the role of genes in determining multifactorial traits?

Contribute along with environmental influences Signup and view all the answers

What type of inheritance is responsible for the continuous variation in quantitative traits?

Polygenic and multiallelic inheritance Signup and view all the answers

Which of the following is NOT a factor contributing to the phenotypic variation in quantitative traits?

Maternal effects Signup and view all the answers

Which of the following is NOT a characteristic of quantitative traits?

They show distinct and clear-cut phenotypes. Signup and view all the answers

Which of the following statements is true regarding polygenic inheritance?

It involves the input of more than one gene. Signup and view all the answers

What is the term for the phenomenon where multiple phenotypes can be measured and described in quantitative terms?

Quantitative inheritance Signup and view all the answers

Which of the following is NOT a factor contributing to the variation in quantitative traits?

Simple Mendelian inheritance Signup and view all the answers

What is the primary condition for a set of measurements to form a normal distribution?

The measurements must be taken from a sufficiently large and representative sample Signup and view all the answers

Which of the following is NOT a characteristic of a normal distribution?

Asymmetric Signup and view all the answers

What does the estimation of variance help determine in the study of quantitative traits?

The degree of role of genotype in determining phenotype when the environment also influences the phenotype Signup and view all the answers

How does the mean provide information about a set of measurements for a quantitative trait?

By indicating the central point along a range of measurements Signup and view all the answers

Why is the mean a useful descriptive summary of a sample?

It provides a useful descriptive summary of the sample, but it tells us nothing about the range or spread of the data Signup and view all the answers

What is the unit of measurement for variance?

A squared value of the unit of the measurements Signup and view all the answers

What does the category number 0-4 represent in Nilsson-Ehle's study?

The number of alleles designated by an uppercase letter Signup and view all the answers

What does the 1:4:6:4:1 phenotypic ratio of grain color indicate?

The segregation of alleles according to Mendelian rules Signup and view all the answers

What is the purpose of studying polygenic traits?

To analyze the statistical distribution of a trait in a population Signup and view all the answers

What is the significance of additive alleles in Nilsson-Ehle's study?

They influence the phenotype in a quantitative manner Signup and view all the answers

What does the term 'additive' mean in the context of genetics?

The alleles have a cumulative effect on the phenotype Signup and view all the answers

How does the accuracy of the final results of the measurements depend on the sample selection in a study of polygenic traits?

The accuracy of the final results depends on whether the sample is random and representative of the population Signup and view all the answers

What is the primary purpose of using standard deviation in a normal distribution?

To measure the dispersion of a set of data from its mean Signup and view all the answers