1. 03-Heredity & Environment

3. Genes DNA (deoxyribonucleic acid)  The basis of heredity  Chromosome  Molecule of DNA Make up chromosomes  Humans = 46 (23 pairs) of chromosomes  Genes = Section of chromosomes Allele = Slight normal variation in a gene

4. Genome = Code for making an individual 20,000 genes (99% in other creatures also) Genotype = The full set of genes for a specific orgasm organism (entire genetic inheritance) Phenotype  What you look like based on your genes  Appearance, personality, intelligence Genotype = Hidden in your genes Phenotype = Observable characteristics based on genes – E.g. brown eyes

5. Beginning of life

6. Gamete Sperm Ovum (egg) Each has23 chromosomes (one half of 46)

7. Zygote Single cell from two gametes

8. Male or female? 23 rd pair of chromosomes Female = XX Male = XY

9. Twins Monozygotic (identical) twins  From one zygote  Share 100% genes Dizygotic (fraternal) twins  Two sperm penetrating two ova  Share 50% of their genes

10. ART = Assisted Reproduction Technology IVF = In Vitro Fertilization  Sperm mixed with ova in glass dish  Viable embryos implanted ICSI (Intracytoplasmic sperm injection) Intrafallopian sperm injection

11. One cell to many How genes interact Genotype = Entire set of genes (about 20,000) Phenotype = Appearance (blue eyes) and behavior (alcoholic)

12. Genotype to phenotype How genes affect appearance and behavior Genes + Environment = Phenotype (Appearance & behavior) E.g. Alcoholism  Genes(Varies in intensity) + Environment (Encourages or discourages drinking) = Result

13. Epigenetic All characteristics are determined by both genes and environment  E.g. height and nutrition

14. Additive heredity Some alleles (gene variations) combine to affect appearance and behavior

15. Dominant – recessive heredity Dominate genes are more influential than recessive genes. E.g. Brown eyes (Mother-dominate) + Blue eyes (Father-recessive) = Brown eyed child Being a carrier for blue eyes can effect this

16. Genetic (chromosomal) abnormalities Most often related to age of mother Extra chromosome  E.g. Down Syndrome = 47 chromosomes

17. Abnormalities of the 23 rd. Pair Humans have 44 chromosomes + one X + an “X” or ”Y”  Embryos do not develop without one X Missing chromosome  E.g. XO Three sex chromosomes  XXY  XYY  Appear normal until puberty

18. Genetic Counseling Find harmful conditions Affect insurance coverage Jeopardize the marriage