CAMPBELL BIOLOGY IN FOCUS © 2014 Pearson Education, Inc. Urry Cain Wasserman Minorsky Jackson Reece Lecture Presentations by Kathleen Fitzpatrick and Nicole Tunbridge 11 Mendel and the Gene Idea

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Figure 11.1

© 2014 Pearson Education, Inc. Concept 11.1: Mendel used the scientific approach to identify two laws of inheritance  _________________________________________ _________________________________________

© 2014 Pearson Education, Inc. Figure 11.2 Parental generation (P) Stamens First filial generation offspring (F 1 ) Carpel Technique Results

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© 2014 Pearson Education, Inc.  _________________________________________ _________________________________________  _________________________________________  _________________________________________ _________________________________________

© 2014 Pearson Education, Inc. Figure P Generation Experiment (true-breeding parents) Purple flowers White flowers

© 2014 Pearson Education, Inc. Figure P Generation Experiment (true-breeding parents) F 1 Generation (hybrids) Purple flowers White flowers All plants had purple flowers Self- or cross-pollination

© 2014 Pearson Education, Inc. Figure P Generation Experiment (true-breeding parents) F 1 Generation F 2 Generation (hybrids) Purple flowers White flowers All plants had purple flowers Self- or cross-pollination 705 purple-flowered plants 224 white-flowered plants

© 2014 Pearson Education, Inc. Table 11.1

© 2014 Pearson Education, Inc. Table 11.1a

© 2014 Pearson Education, Inc. Table 11.1b

© 2014 Pearson Education, Inc. Mendel’s Model  _________________________________________  1, _______________________________________ _________________________________________  2, _______________________________________ _________________________________________  3, _______________________________________  4________________________________________ _________________________________________ (and end up in different gametes)

© 2014 Pearson Education, Inc. Figure P Generation Gametes: Appearance: Genetic makeup: Purple flowers PP White flowers pp P p

© 2014 Pearson Education, Inc. Figure P Generation Gametes: Appearance: Genetic makeup: F 1 Generation Purple flowers PP White flowers pp Gametes: Appearance: Genetic makeup: ½ ½ Purple flowers Pp P P p p

© 2014 Pearson Education, Inc. Figure P Generation Gametes: Appearance: Genetic makeup: F 1 Generation F 2 Generation Purple flowers PP White flowers pp Gametes: Appearance: Genetic makeup: Eggs from F 1 (Pp) plant Sperm from F 1 (Pp) plant ½ ½ Purple flowers Pp P P p p P p P p PP pp Pp 3 : 1

© 2014 Pearson Education, Inc.  _________________________________________

© 2014 Pearson Education, Inc. Figure 11.6 Phenotype 1 Genotype Purple White Ratio 3:1 PP (homozygous) Pp (heterozygous) Pp (heterozygous) pp (homozygous) Ratio 1:2:

© 2014 Pearson Education, Inc. Test Cross _________________________________________

© 2014 Pearson Education, Inc. Figure 11.7 Technique Predictions Dominant phenotype, unknown genotype: PP or Pp? Eggs Sperm ½ offspring purple and ½ offspring white Recessive phenotype, known genotype: pp If purple-flowered parent is PP If purple-flowered parent is Pp Eggs Sperm All offspring purple Results or p p P p Pp pp Pp pp p p P P Pp

© 2014 Pearson Education, Inc. Figure 11.8 YRyr YR yr YYRR yyrr YyRr Experiment Predictions P Generation F 1 Generation Predicted offspring in F 2 generation Gametes YYRR yyrr YyRr Results Eggs Sperm or Hypothesis of dependent assortment Phenotypic ratio 3:1 Hypothesis of independent assortment ¾ ¼ ½ ½ ½ ½ ¼ ¼ ¼ ¼ ¼¼ ¼ ¼ YR yr Phenotypic ratio approximately 9:3:3:1 Phenotypic ratio 9:3:3:1 YR yr YR yr YYRR yyrr YYRr YyRr YryR Yr yR YyRR YYRrYYrr Yyrr YyRr YyRRYyRr yyRr yyRR YyRrYyrr yyRr

© 2014 Pearson Education, Inc.  _________________________________________  _________________________________________ _________________________________________  _________________________________________ __________________________________________ ________________________________________

© 2014 Pearson Education, Inc. Degrees of Dominance  _________________________________________ _________________________________________ _________________________________________

© 2014 Pearson Education, Inc. Figure P Generation Gametes White C W Red C R CWCW CRCR

© 2014 Pearson Education, Inc. Figure ½ ½ P Generation F 1 Generation Gametes White C W Pink C R C W Red C R CWCW CRCR CWCW CRCR

© 2014 Pearson Education, Inc. Figure Eggs ½ ½ ½ ½ P Generation F 1 Generation Gametes F 2 Generation Gametes Sperm White C W Pink C R C W Red C R CWCWCWCW CRCWCRCW CRCRCRCR CWCW CRCR CWCW CRCR ½½ CWCW CRCR CWCW CRCR CRCWCRCW

© 2014 Pearson Education, Inc. Multiple Alleles  Most genes exist in populations in more than two allelic forms  For example, the four phenotypes of the ABO blood group in humans are determined by three alleles of the gene: I A, I B, and i.  The enzyme (I) adds specific carbohydrates to the surface of blood cells  The enzyme encoded by I A adds the A carbohydrate, and the enzyme encoded by I B adds the B carbohydrate; the enzyme encoded by the i allele adds neither

© 2014 Pearson Education, Inc. Figure Carbohydrate (b) Blood group genotypes and phenotypes Allele Red blood cell appearance Genotype none B A IBIB Phenotype (blood group) i IAIA IAIBIAIB ii I A I A or I A i I B I B or I B i B A O AB (a) The three alleles for the ABO blood groups and their carbohydrates

© 2014 Pearson Education, Inc. Extending Mendelian Genetics for Two or More Genes  _________________________________________ _________________________________________

© 2014 Pearson Education, Inc. Figure ¼ ¼ ¼ ¼ ¼ ¼ ¼¼ BE Be BE be BBEE bbee BbEE BbEe bEbe bE Be BBEe BbEEbbEE bbEe BbEe BBEeBbEeBbeeBBee BbEebbEe Bbee 9 : 4 : 3 Eggs Sperm BbEe

© 2014 Pearson Education, Inc. Polygenic Inheritance  _________________________________________ _________________________________________

© 2014 Pearson Education, Inc. Figure Eggs Sperm AaBbCc Phenotypes: 0 Number of dark-skin alleles:

© 2014 Pearson Education, Inc. Fig , p.181 Describing Continuous Variation

© 2014 Pearson Education, Inc. Nature and Nurture: The Environmental Impact on Phenotype  _________________________________________ _________________________________________

© 2014 Pearson Education, Inc. Temperature Effects on Phenotype This Rabbit is homozygous for allele producing heat-sensitive version of an enzyme in melanin-producing pathway Melanin is produced in cooler areas of body Figure Page 179

© 2014 Pearson Education, Inc. This Siamese cat, raised in a cold environment in Moscow in the late 20s, developed a relatively dark coat. An area on his shoulder was shaved, and the cat wore a warm jacket while the fur was growing back. When the shaved hair grew back in, it was white, the same color as the cat's belly, due to the increased temperature under the jacket. This was not due to scarring, as the hair grew in normally colored later.

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Figure WW or Ww ww Ww No widow’s peak Widow’s peak wwWw 1st generation (grandparents) 3rd generation (two sisters) 2nd generation (parents, aunts, and uncles) Affected male Affected female MaleFemale Key Mating Attached earlobe Free earlobe Offspring, in birth order (first-born on left) FF or Ff ff Ff ff FfFF or Ff ffFf (a) Is a widow’s peak a dominant or recessive trait? (b) Is an attached earlobe a dominant or recessive trait?

© 2014 Pearson Education, Inc. Figure Parents Sperm Normal Aa Normal Aa Eggs AA Normal Aa Normal (carrier) Aa Normal (carrier) aa Albino A a Aa

© 2014 Pearson Education, Inc. Sickle-Cell Disease: A Genetic Disorder with Evolutionary Implications  ____________________affects one out of 400 African-Americans  _________________________________________ _________________________________________  Symptoms include physical weakness, pain, organ damage, and even paralysis  _________________________________________,

© 2014 Pearson Education, Inc. Fig. 12-5, p.190 Autosomal Dominant Inheritance example… Achondro- plasia

© 2014 Pearson Education, Inc. Achondroplasia  _________________________________________ _________________________________________ _________________________________________ _________________________________________

© 2014 Pearson Education, Inc. Huntington Disorder  Autosomal dominant allele  Causes involuntary movements, nervous system deterioration, death  Symptoms appear after age 30  People often pass allele on before they know they have it

© 2014 Pearson Education, Inc. Huntington Disorder

© 2014 Pearson Education, Inc. Hutchinson-Gilford Progeria  _________________________________________  No evidence of it running in families  _________________________________________  Usually causes death in early teens

© 2014 Pearson Education, Inc. Fig. 12-7, p.191 Hutchinson-Gilford Progeria

© 2014 Pearson Education, Inc. The Y Chromosome  _________________________________________ ___________________________________________ _______________________________________

© 2014 Pearson Education, Inc. Fig , p.183

© 2014 Pearson Education, Inc. Fig , p.183