Opening Essay
Explain how canine genetics can provide insight into human inheritance.
Mendel’s Laws
9.1 Describe pangenesis theory and the blending hypothesis. Explain why both ideas are now rejected.
9.2 Explain why Mendel’s decision to work with peas was a good choice. Define and distinguish between truebreeding organisms, hybrids, the P generation, the F1 generation, and the F2 generation.
9.3 Define and distinguish between the following pairs of terms: genotype and phenotype; dominant allele and recessive allele; heterozygous and homozygous. Also, define a monohybrid cross and a Punnett square.
9.3 Explain how Mendel’s law of segregation describes the inheritance of a single characteristic.
9.4 Describe the genetic relationship between homologous chromosomes.
9.5
Explain how Mendel’s law of independent assortment applies to a dihybrid cross. Illustrate this law with examples from Labrador retrievers and Mendel’s work with peas.
9.6 Explain how a testcross is performed to determine the genotype of an organism.
9.7 Explain how and when the rule of multiplication and the rule of addition can be used to determine the probability of an event. Explain why Mendel was wise to use large sample sizes in his studies.
9.8 Explain how family pedigrees can help determine the inheritance of many human traits.
9.9 Explain how recessive and dominant disorders are inherited. Provide examples of each.
9.10 Compare the health risks, advantages, and disadvantages of the following forms of fetal testing: amniocentesis, chorionic villus sampling, and ultrasound imaging. Describe the ethical dilemmas created by advances in biotechnology.
Variations on Mendel’s Laws
9.11
–9.15 Describe the inheritance patterns of incomplete dominance, multiple alleles, codominance, pleiotropy, and polygenic inheritance. Provide an example of each.
9.13 Explain how the sickle-cell allele can be adaptive.
9.15 Explain why human skin coloration is not sufficiently explained by polygenic inheritance.
The Chromosomal Basis of Inheritance
9.16 Define the chromosome theory of inheritance. Explain the chromosomal basis of the laws of segregation and independent assortment.
9.17 Explain how linked genes are inherited differently from nonlinked genes.
9.18
Describe T. H. Morgan’s studies of crossing over in fruit flies. Explain how crossing over produces new combinations of alleles.
9.19 Explain how Sturtevant created gene maps.
Sex Chromosomes and Sex-Linked Genes
9.20 Explain how sex is genetically determined in humans and the significance of the SRY gene. Compare the sex determination system in humans to those in fruit flies, grasshoppers, birds, and bees.
9.21
–9.22 Describe patterns of sex-linked inheritance, noting examples in fruit flies and humans.
9.22 Explain why sex-linked disorders are expressed much more frequently in men than in women.
9.23 Explain how the Y chromosome can be used to trace human ancestry.
ABO blood groups achondroplasia allele amniocentesis carrier character chorionic villus sampling (CVS) chromosome theory of inheritance codominant complete dominance cross cross-fertilization
Student Media
Mendel’s Laws cystic fibrosis dihybrid cross dominant allele
Duchenne muscular dystrophy
F1 generation
F2 generation genotype hemophilia heterozygous homozygous
Huntington’s disease hybrid inbreeding incomplete dominance law of independent assortment law of segregation linked genes monohybrid cross
P generation pedigree phenotype pleiotropy polygenic inheritance
Punnett square recessive allele recombination frequency red-green colorblindness rule of addition rule of multiplication self-fertilize sex chromosome sex-linked gene testcross trait true-breeding ultrasound imaging
Mrs. Loyd
 cloyd@waukee.k12.ia.us
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Activity: Monohybrid Cross (9.3)
Activity: Dihybrid Cross (9.6)
Activity: Gregor’s Garden (9.7)
Discovery Channel Video Clip: Colored Cotton (9.2)
Video: Ultrasound of Human Fetus 1 (9.10)
Video: Ultrasound of Human Fetus 2 (9.10)
BLAST Animation: Single-Trait Crosses (9.3)
BLAST Animation: Genetic Variation: Independent Assortment (9.5)
BLAST Animation: Two-Trait Crosses (9.5)
Variations on Mendel’s Laws
Activity: Incomplete Dominance (9.11)
The Chromosomal Basis of Inheritance
MP3 Tutor: Chromosomal Basis of Inheritance (9.16)
Activity: Linked Genes and Crossing Over (9.19)
Sex Chromosomes and Sex-Linked Genes
Activity: Sex-Linked Genes (9.21)
Process of Science: How is the Chi-Square Test Used in Genetic Analysis? (9.21)
Mrs. Loyd
 cloyd@waukee.k12.ia.us
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Check off each of the types of genetic crosses as you understand them.
Mendelian Crosses:
 Parental
 F
1
 F
2 monohybrid:
 (Hom x Hom) PP x pp
 (Het x Hom)
 (Het x Het)
 Test Cross
Bb x bb
Bb x Bb
BB? or Bb? x bb
 Incomplete Dominance Rr x Rr
 Codominance RR x WW dihybrid:
 (Hom x Hom)
 (Het x Het)
RRYY x rryy This results in a one-square Punnett Square.
RrYy x RrYy This results in a sixteen square Punnett. polygenic:
 two genes, one trait G: AABB = tallest: P
G: aabb = shortest: P
 Cross two medium: AaBb x AaBb, Give the phenotypic ratios.
Chromosomal Inheritance
Chromosomes
 sex chromosomes and autosomes
 sex determination
 sex-linked traits
 linked genes (autosomal)
X R X R x X r Y
GgL l
x gg ll
G g g g
L
l x l l
 Chromosome Mapping
 Mutations:
 deletions
 inversion
 translocation
 nondisjunction
 point mutation
 substitution
 frameshift mutation
 insertion
Inheritance Patterns


Pedigrees males= multiple alleles:
 ,  females=  ,  ; affected=  ,  unaffected=  , 
I A = A, I B = B, I i =O
Type A =
Type B =
I A I A or I A I i
I B I B , or I B I i
= AA
= BB
Type AB =
Type O =
I A I B
I i I i
=
=
AB
OO
 X-linked: X C X c x X c Y -
 sex-influenced: Homozygous hair men: normal;
Heterozygous hair/bald men: bald; women: normal women: normal
Homozygous bald men: bald; women: bald
Mrs. Loyd
 cloyd@waukee.k12.ia.us
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