Chapter 3: Genetics Mendel

1
Chapter 3 GeneticsMendels Peas
Discreet Units of Inheritance (genes)
Genes Inherited Independently (Independent
Assortment)
2
Cells
Cell
Cytoplasm
Nucleus
Chromosomes
Diploid Organisms Have Chromosomes Organized in
Homologous Pairs
Humans have 46 Chromosomes (23 Homologous Pairs)
3
Cell Division
Meiosis Making Sex Cells
Mitosis Making Somatic Cells
Haploid Gametes (eggs sperm)
Diploid Daughter Cells
4
Genes DNAAlleles(different varieties of genes)
Homozygous
Heterozygous
5
Terms

• Genotype the particular genes or alleles that
  an individual has
• Phenotype the observable trait of a
  individuals genotype
• Dominant individuals with only one copy of the
  allele have the same phenotype
• Recessive individuals need two copies of the
  allele, no effect in the heterozygotes

6
Mendels Peas AgainF0 to F1
Parent Generation (F0)
True Breeding for Seed Color Homozygous Genotypes
AA aa Phenotype Yellow Green
Meiosis
Haploid Sex Cells
Sex
Heterozygous Genotype Aa Phenotype Yellow
Daughter Generation (F1)
7
Mendels Peas AgainF1 to F2
Genotype Aa Phenotype Yellow
F1 Generation
Meiosis
Sex
F2 Generation
8
Punnett Square
A a
AA Aa
A a
Aa aa
Genotype 121 Phenotype 31
9
Punnett Square
A a
AA Aa
A A
AA Aa
Genotype 11 Phenotype 1
10
Punnett Square
a a
Aa Aa
A A
Aa Aa
Genotype 1 Phenotype 1
11
Punnett Square
a a
Aa Aa
A a
aa aa
Genotype 11 Phenotype 11
12
Punnett Square 2 Genes/Traits
ab ab
Aa Aa Bb Bb
A B A B
Aa Aa Bb Bb
Genotype 11 Phenotype 11
13
Punnett Square 2 Genes/Traits
AB Ab aB ab
AA Bb
AA BB
Aa Bb
Aa BB
AB Ab aB ab
Aa bb
AA Bb
Aa Bb
AA bb
Aa BB
Aa Bb
aa BB
aa Bb
Aa Bb
Aa bb
aa Bb
aa bb
Genotype All Different Phenotype 9331
14
Crossover
15
DNA Deoxyribonucleic Acid
Bases
Backbone Is made of Phosphates Sugars
Adenine
Thymine
Cytosine
Guanine
Paired
16
Making an Exact Copy
17
Making a Protein
Amino Acid 3
Amino Acid 2
Amino Acid 1
tRNA
C G G
A U U
C G A
U A A G C U G G C
Cytoplasm
mRNA