Unit 4 – Reproduction and
Genetics
Lesson 11 - Mendel and
Genetics
Colorado Agriscience Curriculum
I. 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
Unit 4, Lesson 11 Mendal and Genetics
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I. 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 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
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I. 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.
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I. Gregor Mendel
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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.
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Unit 4, Lesson 11 Mendal and Genetics
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III. Genes Located on
Corresponding Homologous
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
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IV: 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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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
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