Unit 4 – Reproduction and Unit 4 – Reproduction and Genetics Genetics

Lesson 11 - Mendel and Lesson 11 - Mendel and GeneticsGenetics

Colorado Agriscience Curriculum Colorado Agriscience Curriculum

Unit 4, Lesson 11 Mendal and Genetics Unit 4, Lesson 11 Mendal and Genetics PPPP 22

I. Gregor MendelI. Gregor Mendel

• A) Geneticist who first developed the rules to predicting the pattern of heredity– 1) Monk who did experiments with peas

• B) Heredity – 1. passing of traits such as coat color, polled

or horned, height, etc. from parents to offspring

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I. Gregor MendelI. Gregor Mendel

• C) Breeding Generations– 1. P Generation

• a) parental generation

– 2. F1 Generation• a) Filial Generation• b) 1st offspring of P Generation

– 3. F2 Generation• a) 2nd Filial Generation

• b) offspring of F1 Generation

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I. Gregor MendelI. Gregor Mendel

• D)3 Steps of Mendel’s Experiment – 1. P Generation

• a) Allowed each variety to self pollinate for several generations– 1. ensure that all offspring would display only one form of a

particular trait (flower color)

– 2. Crossbred the two strains of the P generation • - Recorded Data• - Resulted in all purple flowers

Unit 4, Lesson 11 Mendal and Genetics Unit 4, Lesson 11 Mendal and Genetics PPPP 55

I. Gregor MendelI. Gregor Mendel

• D)3 Steps of Mendel’s Experiment

– 3. Allowed the F1 Generation to self-pollinate

• a) Resulted in the F2 Generation

• b) 1 out of every four flowers was white.

Unit 4, Lesson 11 Mendal and Genetics Unit 4, Lesson 11 Mendal and Genetics PPPP 66

I. Gregor MendelI. Gregor Mendel

Unit 4, Lesson 11 Mendal and Genetics Unit 4, Lesson 11 Mendal and Genetics PPPP 77

II. Traits II. Traits

• A) Chromosomes and Genes are in pairs– 1. One chromosome is contributed by each parent– 2. Chromosome Locus

• a) site where a gene is found on a chromosome

• B) Traits– 1. For each inherited trait an individual has, there are

two copies of that gene ( 1 from each parent)– 2. Genes are what causes traits to appear

• a) each version is called an allele • a) eye color, coat color, marbling, ribeye area, etc.

Unit 4, Lesson 11 Mendal and Genetics Unit 4, Lesson 11 Mendal and Genetics PPPP 88

Unit 4, Lesson 11 Mendal and Genetics Unit 4, Lesson 11 Mendal and Genetics PPPP 99

III. Genes Located on III. Genes Located on Corresponding Homologous Corresponding Homologous

Chromosomes may:Chromosomes may:• A) Correspond to each other

– 1. homozygous

• B) Differ from each other– 2. heterozygous

• C) Genes on corresponding chromosomes that control the same trait are called alleles

Unit 4, Lesson 11 Mendal and Genetics Unit 4, Lesson 11 Mendal and Genetics PPPP 1010

IV: AllelesIV: Alleles

• A) Homozygous (BB or bb)– 1. both alleles are the same

• B) Heterozygous (Bb)– 1. two alleles are different

• C) The dominant (capital) allele is always expressed when it is present

• D) The recessive allele is only expressed when both copies of the gene are recessive

Unit 4, Lesson 11 Mendal and Genetics Unit 4, Lesson 11 Mendal and Genetics PPPP 1111

V: Genotype and Phenotype V: Genotype and Phenotype

• A) Genotype – 1. amount, order, and type of genes an

individual has– 2. genetic make-up of an individual

• B) Phenotype – 1. Physical traits an individual possesses – 2. Doesn’t take into account masked traits

only expressed or dominant traits