2 1. Introduction 2. Fact or Fiction? 3. The Genetic Code 4. From One Cell to Many 5. From Genotype to Phenotype 6. Chromosomal and Genetic Abnormalities 7. Closing Thoughts

Introduction 3 [Video: Heredity and Environment Introduction]

4 Fact or Fiction?FictionFact 1. No two cells of the human body contain exactly the same material. 2. Not all individuals are born genetically unique. 3. All the genes a person has show up as observable traits. 4. Alcoholism is inherited.

5 The molecular beginnings of human development Deoxyribonucleic Acid (DNA): The chemical composition of the molecules that contain genes. chromosome: One of 46 molecules of DNA (in 23 pairs) that virtually each cell of the human body contains and that, together, contain all the genes. Other species have more or fewer chromosomes. gene: The basic unit for the transmission of heredity. Chromosome DNA

What Genes Are 6 How are proteins made? allele: A variation that makes a gene different in some ways from other genes for the same characteristics.

What makes a child who he is? The Beginnings of Life 7 gamete: A reproductive cell (a sperm or ovum).

New Cells New Functions How do genes work in combination to build a person? 8 genome: The full set of genes; instructions to make an individual member of a certain species. polygenic: A trait influenced by many genes. multifactorial: A trait affected by many factors, both genetic and environmental in expression.

What are the possible gene combinations in a zygote? Mother’s two genes Father’s two genes F1M1F1M1 F1M2F1M2 F2M1F2M1 F2M2F2M2 M2M2 M1M1 F1F1 F2F2 Gene-Gene Interactions 9 genotype: An organism’s entire genetic inheritance, or genetic potential. phenotype: The observable characteristics of a person.

23rd PairPhenotypeGenotypeNext Generation 1. XXNormal womanNot a carrierNo color blindness from mother 2. XYNormal manNormal X from motherNo color blindness from father 3. XXNormal womanCarrier from father Half her children will inherit her X. The girls with her X will be carriers; the boys with her X will be color-blind. 4. XXNormal womanCarrier from mother Half her children will inherit her X. The girls with her X will be carriers; the boys with her X will be color-blind. 5. XYColor-blind manInherited from mother All his daughters will have his X. None of his sons will have his X. All his children will have normal vision, unless their mother also had an X for colorblindness. 6. XX Color-blind woman (rare) Inherited from both parents Every child will have one X from her. Therefore, every son will be color-blind. Daughters will be only carriers, unless they also inherit an X from the father, as their mother did. How do x-linked genes affect heredity? The 23rd Pair and X-Linked Color Blindness More Complications x-linked: Referring to a gene carried on the X chromosome. 10 The X indicates an X chromosome with the X-linked gene for color blindness

X-linked: Referring to a gene carried on the X chromosome. What happens to behavior as alcohol progresses from one brain part to another? Addiction 11 Binge Drinking Among 14,000 Students in 119 Four-Year Colleges 44% 56% Binge-drinking episode No binge-drinking episode 44% 56%

What effect do college policies have on the drinking behavior of college students? Addiction 12 BANNO BAN abstinence binge-drinking 39% 29% 48% 16%

13 Baby’s eyes reflexively follow the moving pattern Baby’s eyes do not follow the moving pattern Visual Acuity How are babies tested for nearsightedness?

14 Practical Applications 14 What do you know about your biochemistry? No thanks

Not Exactly 46 Chromosomes What is Down Syndrome? down syndrome (Trisomy-21): A condition in which a person has 47 chromosomes instead of the usual 46, with 3 rather than 2 chromosomes on the 21st site, resulting in distinctive characteristics. 15

16 Genetic Counseling and Testing What do prospective parents learn from genetic counseling and testing? genetic counseling: Consultation and testing by trained experts that enable individuals to learn about their genetic heritage. [Video: 3D ultrasound]

17 Genetic Counseling and Testing [Audio: Fetal Heartbeat]

Closing Thoughts 18 What are some examples of how genes and environment have interacted to influence your development or the development of someone you know well?