Download Chapter 10:

Chapter 10:
Patterns of Inheritance
Concept 10.1
Genetics Developed from curiosity
about inheritance…
Vocab
• Trait
• Genetics
• Cross Fertilization
Blending Theory
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Early 1800’s
Blue x Red = Purple
Purple always produce purple
Problems with theory…
Gregor Mendel
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Austrian Monk
Taught High School Biology
Mathematician
Lived in a Monestary
Bred Pea Plants in Garden
Crossed generations for 7 years
Mendel’s Theory
• Particulate Hypothesis
– True-breeding
– Led to “Genetics”
• Used self- vs. cross-fertilization
Concept 10.2
Mendel discovered that inheritance
follows rules of chance…
Vocab
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Hybrids
Monohybrid cross
Allelese
Homozygous
Heterozygous
Dominant
Recessive
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Phenotype
Genotype
Testcross
Dihybrid cross
Principle of
Segregation
• Principle of
Independent
Assortment
• Generations
Principle of
Segregation
• True
breeding=pure
(homozygous)
• True x true =
hybrid
Pea Traits:
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Allele= purple vs. white
Dominant= Capital (B)
Recessive= Lowercase (b)
Homozygous= BB or bb
Heterozygous = Bb
Principle of Segregation
• Alleles separate into different gametes
during meiosis…
Probability
• The mathematical prediction that a specific
event will occur!
• Written as fractions, decimals, or percents!
Genotype vs. Phenotype
• Genotype= Gene Combination (BB, Bb, or bb)
• Phenotype= What it looks like (Black vs. Fawn)
Testcross:
• Cross between one known parent and one
unknown parent to determine the genotype
of the unknown.
10.4 Meiosis Explains Mendel
Chromosome Theory of
Inheritance
• Genes are located on chromosomes
• Chromosome behavior accounts for
inheritance
• Chromosomes undergo segregation and
independent assortment
Reminder…Karyotype
Gene Locus
• Each gene has a specific location on each
chromsome
Genetic Linkage
• Same chromosome = genes linked
– Unless crossing over occurs
• Blue eyes paired with blonde hair
• Brown eyes paired with brown hair
10.5
Sex-linked traits have unique
inheritance patterns…
Sex Linked Genes
• A gene that is located on the sex
chromosome
• Discovered by Thomas Hunt Morgan
– Studied eye color in fruit flies
• Result in unusual inheritance ratios
(patterns)
Sex-Linked Disorders
• Red-green color blindness, hemophilia,
male pattern baldness, etc.
• Recessive traits more common in men!
– Usually allele is absent on the y chromosome