Go to Section:

The Father of Genetics – Gregor Johann Mendel ( ) Mendel cultivated and tested some pea plants

Go to Section: Allele – Different form of a gene Dominant allele - In a heterozygote, the allele that is fully expressed in the phenotype. Recessive allele - In a heterozygote, the allele that is completely masked in the phenotype. Phenotype – The outward appearance of a trait Genotype – The combination of alleles (Letters)

Go to Section: Mendel’s Experiments Used 34 "true-breeding" strains of the common garden pea plant These strains differed from each other in very pronounced (visible) ways so that there could be no doubt as the results of a given experiment. Pea plants were perfect for such experiments since their flowers had both male (anthers) and female (pistils) flower parts The flower petals never open therefore no foreign pollen could enter and back crosses (self fertilization) was easy.

Go to Section:

Flower Parts

Go to Section: P Generation F 1 Generation F 2 Generation TallShortTall Short Section 11-1 Principles of Dominance

Go to Section: P Generation F 1 Generation F 2 Generation TallShortTall Short Section 11-1 Principles of Dominance

Go to Section: P Generation F 1 Generation F 2 Generation TallShortTall Short Section 11-1 Principles of Dominance

Go to Section: Seed Shape Flower Position Seed Coat Color Seed Color Pod Color Plant Height Pod Shape Round Wrinkled Round Yellow Green Gray White Smooth Constricted Green Yellow Axial Terminal Tall Short YellowGraySmoothGreenAxialTall Section 11-1 Figure 11-3 Mendel’s Seven F 1 Crosses on Pea Plants

Go to Section: 11–2Probability and Punnett Squares A.Genetics and Probability B.Punnett Squares C.Probability and Segregation D.Probabilities Predict Averages Section 11-2 Section Outline

Go to Section: Section 11-2 Tt X Tt Monohybrid Cross

Go to Section: Section 11-2 Tt X Tt Cross

Go to Section: Monohybrid Cross Phenotypes

Go to Section: Law of Segregation

Go to Section: 11–3Exploring Mendelian Genetics A.Independent Assortment 1.The Two-Factor Cross: F 1 2.The Two-Factor Cross: F 2 B.A Summary of Mendel’s Principles C.Beyond Dominant and Recessive Alleles 1.Incomplete Dominance 2.Codominance 3.Multiple Alleles 4.Polygenic Traits D.Applying Mendel’s Principles E.Genetics and the Environment Section 11-3 Section Outline

Go to Section: concluded that which is called the Gregor Mendel Law of Dominance Law of Segregation Pea plants “Factors” determine traits Some alleles dominant, & some alleles recessive Alleles are separated during gamete formation Section 11-3 Concept Map experimented with

Go to Section: Section 11-3 Figure Independent Assortment in Peas

Go to Section: Section 11-2 Dihybrid Cross

Go to Section: Section 11-3 Figure Incomplete Dominance in Four O’Clock Flowers

Go to Section: Section 11-3 Figure Incomplete Dominance in Four O’Clock Flowers

Go to Section: 11–4Meiosis A.Chromosome Number B.Phases of Meiosis 1.Meiosis I 2.Meiosis II C.Gamete Formation D.Comparing Mitosis and Meiosis Section 11-4 Section Outline

Go to Section: Homologous Chromosome

Go to Section: Section 11-4 Crossing-Over

Go to Section: Section 11-4 Crossing-Over

Go to Section: Section 11-4 Crossing-Over

Go to Section:

Meiosis I Section 11-4 Figure Meiosis

Go to Section: Meiosis I Section 11-4 Figure Meiosis Meiosis I

Go to Section: Meiosis I Section 11-4 Figure Meiosis Meiosis I

Go to Section: Section 11-4 Figure Meiosis Meiosis I

Go to Section: Section 11-4 Figure Meiosis Meiosis I

Go to Section: Meiosis II Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original. Prophase IIMetaphase IIAnaphase IITelophase II The chromosomes line up in a similar way to the metaphase stage of mitosis. The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid (N) daughter cells. Section 11-4 Figure Meiosis II

Go to Section: Meiosis II Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original. Prophase IIMetaphase IIAnaphase IITelophase II The chromosomes line up in a similar way to the metaphase stage of mitosis. The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid (N) daughter cells. Section 11-4 Figure Meiosis II

Go to Section: Meiosis II Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original. Prophase IIMetaphase IIAnaphase IITelophase II The chromosomes line up in a similar way to the metaphase stage of mitosis. The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid (N) daughter cells. Section 11-4 Figure Meiosis II

Go to Section: Meiosis II Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original. Prophase IIMetaphase IIAnaphase IITelophase II The chromosomes line up in a similar way to the metaphase stage of mitosis. The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid (N) daughter cells. Section 11-4 Figure Meiosis II

Go to Section: Meiosis II Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original. Prophase IIMetaphase IIAnaphase IITelophase II The chromosomes line up in a similar way to the metaphase stage of mitosis. The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid (N) daughter cells. Section 11-4 Figure Meiosis II

Go to Section: Genetic Recombination

Go to Section: Forever Linked? Some genes appear to be inherited together, or “linked.” If two genes are found on the same chromosome, does it mean they are linked forever? Study the diagram, which shows four genes labeled A–E and a–e, and then answer the questions on the next slide. Section 11-5 Interest Grabber

Go to Section: 1.In how many places can crossing over result in genes A and b being on the same chromosome? 2.In how many places can crossing over result in genes A and c being on the same chromosome? Genes A and e? 3.How does the distance between two genes on a chromosome affect the chances that crossing over will recombine those genes? Section 11-5 Interest Grabber continued

Go to Section: 11–5Linkage and Gene Maps A.Gene Linkage B.Gene Maps Section 11-5 Section Outline

Go to Section: Earth Country State City People Cell Chromosome Chromosome fragment Gene Nucleotide base pairs Section 11-5 Comparative Scale of a Gene Map Mapping of Earth’s Features Mapping of Cells, Chromosomes, and Genes

Go to Section: Exact location on chromosomesChromosome 2 Section 11-5 Figure Gene Map of the Fruit Fly

Video 1 Click the image to play the video segment. Video 1 Meiosis Overview

Video 2 Click the image to play the video segment. Video 2 Animal Cell Meiosis, Part 1

Video 3 Click the image to play the video segment. Video 3 Animal Cell Meiosis, Part 2

Video 4 Click the image to play the video segment. Video 4 Segregation of Chromosomes

Video 5 Click the image to play the video segment. Video 5 Crossing Over

Section 5 Answers Interest Grabber Answers 1.In how many places can crossing over result in genes A and b being on the same chromosome? One (between A and B) 2.In how many places can crossing over result in genes A and c being on the same chromosome? Genes A and e? Two (between A and B and A and C); Four (between A and B, A and C, A and D, and A and E) 3.How does the distance between two genes on a chromosome affect the chances that crossing over will recombine those genes? The farther apart the genes are, the more likely they are to be recombined through crossing over.