Figure 14-01

LE 14-2 Removed stamens from purple flower Transferred sperm- bearing pollen from stamens of white flower to egg- bearing carpel of purple flower Parental generation (P) Stamens Carpel Pollinated carpel matured into pod Planted seeds from pod Examined offspring: all purple flowers First generation offspring (F1)

Removed stamens from purple flower Transferred sperm- LE 14-2a Removed stamens from purple flower Transferred sperm- bearing pollen from stamens of white flower to egg- bearing carpel of purple flower Parental generation (P) Stamens Carpel Pollinated carpel matured into pod Planted seeds from pod

Examined offspring: all purple flowers First generation offspring (F1) LE 14-2b Examined offspring: all purple flowers First generation offspring (F1)

(true-breeding parents) White flowers LE 14-3 P Generation (true-breeding parents) Purple flowers White flowers F1 Generation (hybrids) All plants had purple flowers F2 Generation

Table 14-1

Allele for purple flowers Homologous pair of chromosomes Locus for flower-color gene Allele for white flowers

Purple flowers PP White flowers pp P p Purple flowers Pp P Generation Appearance: Purple flowers PP White flowers pp Genetic makeup: Gametes: P p F1 Generation Appearance: Genetic makeup: Purple flowers Pp

3 : 1 LE 14-5_2 P Generation Appearance: Purple flowers PP White Genetic makeup: Gametes P p F1 Generation Appearance: Genetic makeup: Purple flowers Pp Gametes: 1 2 P 1 2 p F1 sperm P p F2 Generation P PP Pp F1 eggs p Pp pp 3 : 1

Phenotype Genotype PP (homozygous Purple 1 Pp (heterozygous 3 Purple 2 White 1 Ratio 3:1 Ratio 1:2:1

LE 14-7 Dominant phenotype, unknown genotype: PP or Pp? Recessive phenotype, known genotype: pp If PP, then all offspring purple: If Pp, then 1 2 offspring purple and 1 2 offspring white: p p p p P P Pp Pp Pp Pp P P Pp Pp pp pp

LE 14-8 P Generation YYRR yyrr Gametes YR yr YyRr F1 Generation Hypothesis of dependent assortment Hypothesis of independent assortment Sperm 1 YR 1 Yr yR yr Sperm 4 4 1 4 1 4 Eggs 1 YR yr 2 1 2 1 YR Eggs 4 YYRR YYRr YyRR YyRr 1 YR F2 Generation (predicted offspring) 2 YYRR YyRr 1 Yr 4 YYRr YYrr YyRr Yyrr 1 yr 2 YyRr yyrr 1 yR 4 YyRR YyRr yyRR yyRr 3 4 1 4 1 yr 4 Phenotypic ratio 3:1 YyRr Yyrr yyRr yyrr 9 16 3 16 3 16 3 16 Phenotypic ratio 9:3:3:1

Rr Rr Segregation of alleles into eggs Segregation of alleles into sperm Sperm 1 R 1 r 2 2 R R R r 1 R 2 1 1 4 4 Eggs r r R r 1 r 2 1 1 4 4

LE 14-10 P Generation Red CRCR White CWCW Gametes CR CW Pink CRCW F1 Generation Gametes 1 1 2 CR 2 CW Sperm 1 2 CR 1 2 CW Eggs F2 Generation 1 CR 2 CRCR CRCW 1 2 CW CRCW CWCW

P Generation Red CRCR White CWCW Gametes CR CW LE 14-10a P Generation Red CRCR White CWCW Gametes CR CW

Pink CRCW F1 Generation Gametes CR CW LE 14-10b Pink CRCW F1 Generation Gametes 1 CR 1 CW 2 2

Sperm CR CW Eggs F2 Generation CR CRCR CRCW CW CRCW CWCW LE 14-10c Sperm 1 CR 1 CW 2 2 Eggs F2 Generation 1 CR 2 CRCR CRCW 1 CW 2 CRCW CWCW

Table 14-2

LE 14-11 BbCc BbCc Sperm BC bC Bc bc BC BBCC BbCC BBCc BbCc bC BbCC 9 3 4 16 16 16

20/64 15/64 6/64 1/64 LE 14-12 AaBbCc AaBbCc aabbcc Aabbcc AaBbcc Fraction of progeny 6/64 1/64

Figure 14-13

Dominant trait (widow’s peak) LE 14-14a First generation (grandparents) Ww ww ww Ww Second generation (parents plus aunts and uncles) Ww ww ww Ww Ww ww Third generation (two sisters) WW ww or Ww Widow’s peak No widow’s peak Dominant trait (widow’s peak)

Recessive trait (attached earlobe) LE 14-14b First generation (grandparents) Ff Ff ff Ff Second generation (parents plus aunts and uncles) FF or Ff ff ff Ff Ff ff Third generation (two sisters) ff FF or Ff Attached earlobe Free earlobe Recessive trait (attached earlobe)

Figure 14-15

Figure 14-16

LE 14-17a Amniocentesis Amniotic fluid withdrawn A sample of amniotic fluid can be taken starting at the 14th to 16th week of pregnancy. Fetus Centrifugation Placenta Uterus Cervix Fluid Fetal cells Biochemical tests can be performed immediately on the amniotic fluid or later on the cultured cells. Biochemical tests Several weeks Fetal cells must be cultured for several weeks to obtain sufficient numbers for karyotyping. Karyotyping

LE 14-17b Chorionic villus sampling (CVS) A sample of chorionic villus tissue can be taken as early as the 8th to 10th week of pregnancy. Fetus Suction tube inserted through cervix Placenta Chorionic villi Fetal cells Biochemical tests Karyotyping and biochemical tests can be performed on the fetal cells immediately, providing results within a day or so. Several hours Karyotyping

George Arlene Sandra Tom Sam Wilma Ann Michael Carla Daniel Alan Tina LE 14-UN273 George Arlene Sandra Tom Sam Wilma Ann Michael Carla Daniel Alan Tina Christopher