Unit 4

1
Unit 4 Reproduction and Genetics Lesson 11 -
Mendel and Genetics

• Colorado Agriscience Curriclum

2
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

3
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

4
I. Gregor Mendel

• D)3 Steps of Mendels 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

5
I. Gregor Mendel

• D)3 Steps of Mendels Experiment
• 3. Allowed the F1 Generation to self-pollinate
• a) Resulted in the F2 Generation
• b) 1 out of every four flowers was white.

6
I. Gregor Mendel
7
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.

8
(No Transcript)
9
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

10
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

11
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. Doesnt take into account masked traits only
  expressed or dominant traits