Chapter 3Mendelian Genetics

Art and Photos in PowerPoint®

Concepts of GeneticsNinth Edition

Klug, Cummings, Spencer, Palladino

Copyright © 2009 Pearson Education, Inc.

http://www.mendelweb.org

Figure 3.1

3.1 Mendel Used a Model Experimental Approach to Study Patterns of Inheritance

3.2 The Monohybrid Cross Reveals How One Trait Is Transmitted from Generation to Generation

• Pairs of Unit Factors of Inheritance (aka “genes”)

• Dominance/Recessiveness

• Principle of Segregation

Mendel’s First Three Postulates:

Figure 3.2

Figure 3.3

Fig 3-3

How can we determine the genotype of an organism displaying a dominant phenotype?

3.2 The Monohybrid Cross Reveals How One Trait Is Transmitted from Generation to Generation

3.2.5 The Testcross: One Character

Figure 3.4

Figure 3.4a

Figure 3.4b

3.3 Mendel’s Dihybrid Cross Generated a Unique F2 Ratio

Figure 3.5

Figure 3.6

Mendel’s Dihybrid Cross Revealed His Fourth Postulate:

Independent Assortment

Figure 3.7

Fig 3-7

Fig 3-7

How many phenotypes and genotypes do you expect among the F2 generation?

Fig 3-7

3.3 Mendel’s Dihybrid Cross Generated a Unique F2 Ratio

3.3.2 The Testcross: Two Characters

Figure 3.8

3.4 The Trihybrid Cross Demonstrates That Mendel’s Principles Apply to Inheritance of Multiple Traits

Figure 3-9 Copyright © 2006 Pearson Prentice Hall, Inc.

Trihybrid cross

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3.4 The Trihybrid Cross Demonstrates That Mendel’s Principles Apply to Inheritance of Multiple Traits

3.4.1 The Forked-Line Method, or Branch Diagram

Figure 3.10

Table 3.1

3.5 Mendel’s Work Was Rediscovered in the Early Twentieth Century

3.6 The Correlation of Mendel’s Postulates with the Behavior of Chromosomes Provided the Foundation of Modern Transmission Genetics

3.6.1 Unit Factors, Genes, and Homologous Chromosomes

Figure 3.11

Figure 3.11a

Figure 3.11b

Figure 3.11c

3.7 Independent Assortment Leads to Extensive Genetic Variation

3.8 Laws of Probability Help to Explain Genetic Events

3.9 Chi-Square Analysis Evaluates the Influence of Chance on Genetic Data

3.9.1 Chi-Square Analysis and the Null Hypothesis

Table 3.3

Figure 3.12ab

Figure 3.12a

Figure 3.12b

3.10 Pedigrees Reveal Patterns of Inheritance of Human Traits

3.10.1 Pedigree Conventions

Figure 3.13

3.10 Pedigrees Reveal Patterns of Inheritance of Human Traits

3.10.2 Pedigree Analysis

Figure 3.14a

Figure 3.14b

Chapt 3, Prob 26

Chapt 3, Prob 27

Chapt 3, Prob 33

Tt Tt

tt

TT or Tt2/3 chance Tt

1/2 x 2/3 =1/3 chance Tt1/3 chance Tt

So, chance that child hasTay Sachs (tt)= 1/4 x 1/3 x 1/3 = 1/36

Table 3.4