Wolf Chinese Shar-Pei Ancestral canine Akita Siberian Husky Fig. 9-0b Wolf Chinese Shar-Pei Ancestral canine Akita Siberian Husky Alaskan Malamute Basenji Afghan hound Saluki Rottweiler Sheepdog Retriever

Figure 9.2C_s3 Figure 9.2C_s3 Mendel’s technique for cross-fertilization of pea plants (step 3) Gregor Mendel performed artificial selection (breeding) experiments on pea plants 2

Character Traits Dominant Recessive Flower color Purple White Figure 9.2D_1 Character Traits Dominant Recessive Flower color Purple White Flower position Axial Terminal Figure 9.2D_1 The seven pea characters studied by Mendel (part 1) Seed color Yellow Green Seed shape Round Wrinkled 3

Character Traits Dominant Recessive Pod shape Inflated Constricted Figure 9.2D_2 Character Traits Dominant Recessive Pod shape Inflated Constricted Pod color Green Yellow Figure 9.2D_2 The seven pea characters studied by Mendel (part 2) Stem length Tall Dwarf 4

Purple flowers White flowers Figure 9.3A_s2 The Experiment P generation (true-breeding parents)  Purple flowers White flowers F1 generation All plants have purple flowers Figure 9.3A_s2 Crosses tracking one character (flower color) (step 2) 5

of plants have purple flowers of plants have white flowers Figure 9.3A_s3 The Experiment P generation (true-breeding parents)  Purple flowers White flowers F1 generation All plants have purple flowers Fertilization among F1 plants (F1  F1) Figure 9.3A_s3 Crosses tracking one character (flower color) (step 3) F2 generation of plants have purple flowers 3 4 of plants have white flowers 1 4 6

Genetic makeup (alleles) Figure 9.3B_s3 The Explanation P generation Genetic makeup (alleles) Purple flowers White flowers PP pp Gametes All P All p F1 generation (hybrids) All Pp Alleles segregate Gametes 2 1 P 2 1 p Fertilization F2 generation Sperm from F1 plant Figure 9.3B_s3 An explanation of the crosses in Figure 9.3A (step 3) P p Phenotypic ratio 3 purple : 1 white P PP Pp Eggs from F1 plant Genotypic ratio 1 PP : 2 Pp : 1 pp p Pp pp 7

Dominant Traits Recessive Traits Freckles No freckles Widow’s peak Figure 9.8A Dominant Traits Recessive Traits Freckles No freckles Widow’s peak Straight hairline Figure 9.8A Examples of single-gene inherited traits in humans Free earlobe Attached earlobe 8

First generation (grandparents) Ff Ff ff Ff Figure 9.8B First generation (grandparents) Ff Ff ff Ff Second generation (parents, aunts, and uncles) FF or Ff ff ff Ff Ff ff Third generation (two sisters) ff FF or Ff Figure 9.8B A pedigree showing the inheritance of attached versus free earlobes in a hypothetical family Female Male Attached Free 9

Normal Dd Normal Dd Parents  D Sperm d Dd Normal (carrier) DD Normal Figure 9.9A Normal Dd Normal Dd Parents  D Sperm d Dd Normal (carrier) DD Normal D Eggs Offspring Figure 9.9A Offspring produced by parents who are both carriers for a recessive disorder, a type of deafness Dd Normal (carrier) dd Deaf d 10

Table 9.9 Table 9.9 Some Autosomal Disorders in Humans 11

Incomplete dominance P generation  Red RR White rr Gametes R r Figure 9.11A P generation  Red RR White rr Gametes R r F1 generation Pink hybrid Rr Incomplete dominance 2 1 2 1 Gametes R r F2 generation Sperm Figure 9.11A Incomplete dominance in snapdragon flower color 2 1 2 1 R r 2 1 R RR rR Eggs 2 1 Rr rr r 12

Figure 9.12 Co-dominance Blood Group (Phenotype) Antibodies Present in Blood Reaction When Blood from Groups Below Is Mixed with Antibodies from Groups at Left Carbohydrates Present on Red Blood Cells Genotypes O A B AB IAIA or IAi Carbohydrate A A Anti-B IBIB or IBi Carbohydrate B B Anti-A Carbohydrate A and Carbohydrate B AB IAIB None Anti-A O ii Neither Figure 9.12 Multiple alleles for the ABO blood groups Anti-B No reaction Clumping reaction 13

Incomplete dominance Red RR White rr Pink Rr Pleiotropy Single gene Fig. 9-UN2 Incomplete dominance Red RR White rr Pink Rr Pleiotropy Single gene Multiple characters Polygenic inheritance Multiple genes Single characters (such as skin color)