BIOLOGY 3 CH-9 REVIEW

WORKSHOP

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�Genetic Concepts�Single Gene Inheritance�Single Gene Inheritance�Multiple Gene Inheritance�Sex-linked Inheritance

Figure B: Anatomy of pea plant

Figure A: Gregor Mendal; “the

father of modern genetics”

Character Trait

Color Purple

# of stamen 7

Table 1: Examples of characters and

traits of Figure B

CharacterCharacterCharacterCharacter TraitTraitTraitTrait

Table 2:Table 2:Table 2:Table 2: The seven pea

characters studied by Mendal

Figure C: Crosses taking one character (flower color)

Alleles

P

p

Table 3: Possible alleles

Genotype Phenotype

PP Purple

Pp Purple

pp White

Table 4: Possible genotypes

and phenotypes Figure D: Explains Figure C in terms of allele

distribution; discussing genotypes and

phenotypes

Homologous Chromosomes Homologous Chromosomes Homologous Chromosomes Homologous Chromosomes –––– Alleles Alleles Alleles Alleles

Homologous Pairs 1

Chromosomes 2

Gene Loci 3

Alleles P, a, B, b

Genotypes PP, aa, Bb

Figure E: Homologous Chromosomes with

labeled components

Table 5: Explanation of Figure E

The Punnet Square___

Alleles

G (Dom)

g (Rec)

Gg x Gg

GGGG gggg

Genotypes

GG

Gg

gg

Phenotypes

GG Green Eyes

Genotypes Phenotypes Prob.

GG Green Eyes 25%

Gg Green Eyes 50%

gg Blue eyes 25%

GGGG

gggg

GGGGGGGG GgGgGgGg

GgGgGgGg gggggggg

GG Green Eyes

Gg Green Eyes

gg Blue Eyes

Independent Assortment

Inherited DisordersInherited DisordersInherited DisordersInherited Disorders

Figure F: Child with Cystic

Fibrosis (Recessive Disorder)Figure G: Dr. Michael C. Ain

Achondroplasia (Dominant Disorder)

Incomplete Dominance

Genotypes Phenotypes

RR

Rr

rr

Pleiotropy

Text H: Sickle-Cell disease; example of a pleiotropy (single gene

influencing multiple characters)

Polygenic Inheritance

Linked Genes

Crossing Over

Crossing Over (cont.)

Sex Chromosomes

Sex-linked Genes