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Unit 4 Unit 4 –– Reproduction and Reproduction and

Genetics Genetics

Lesson 11 Lesson 11 -- Mendel and Mendel and

GeneticsGenetics

Colorado Agriscience Curriculum Colorado Agriscience Curriculum

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

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

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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

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

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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

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

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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

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I. Gregor MendelI. Gregor Mendel

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

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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

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

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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

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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

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

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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