Chapter 8 GENETICS p 171 GENETICS I Gregor

Chapter 8 GENETICS p. 171 GENETICS

I. Gregor Mendel pg. 171 A. Experiments ○ 1. patterns of heredity ○ 2. genetics pg 171 a. purebred b. filial generation GENETICS

Mendel’s Experiments http: //my. hrw. com/content/hmof/science/ high_school_sci/tx/gr 912/hmd_bio_9780544073890_/dlo/biolo gyvideoclips/index. html? vid=23 GENETICS

B. Findings ○ law of segregation pg. 173 GENETICS

Law of Segregation http: //my. hrw. com/content/hmof/science/ high_school_sci/tx/gr 912/hmd_bio_9780544073890_/dlo/biolo gyvideoclips/index. html? vid=24 GENETICS

II. Heredity – A. Gene- Genes encode proteins that produce a diverse range of traits For each trait, you inherit two copies of the gene, one from each parent GENETICS

B. Alleles are alternative versions of the gene p. 174 1. Homozygous 2. Heterozygous GENETICS

E. Genotype - p. 175 Phenotype - GENETICS

C. Dominant allele - p. 175 Recessive allele - GENETICS

III. Punnett Square – p. 177 A monohybrid cross GENETICS

B. male gametes. C. female gametes- GENETICS

D. Dihybrid Cross - GENETICS

Law of Independent Assortment http: //my. hrw. com/content/hmof/science/ high_school_sci/tx/gr 912/hmd_bio_9780544073890_/dlo/biolo gyvideoclips/index. html? vid=25 GENETICS

E. Probability - p. 173 GENETICS

B= Brown b= blonde B Dad b B BB Bb bb Mom GENETICS pheno ratio: 3: 1 geno ratio: 1: 2: 1

GENETICS

GENETICS

Now lets practice!!! Coin toss activity GENETICS

Crossing Over Recombination- GENETICS

Genetic Linkage- GENETICS

IV. Chromosomes and Phenotype p. 192 A. Carrier○ A heterozygote for a recessive disorder is a carrier ○ Disorders caused by dominant alleles are uncommon (dominate GENETICS

B. Sex-linked genes- Y chromosome genes in mammals are responsible for male characteristics - X chromosome genes in mammals affect many traits GENETICS

Male mammals have an XY genotype. All of a male’s sex-linked genes are expressed. Males have no second copies of sexlinked genes GENETICS

C. Expression of Sex-Linked Genes - Female mammals have an XX genotype - Expression of sex-linked genes is similar to autosomal genes in females - X chromosome inactivation randomly “turns off” one X chromosome. GENETICS

D. Incomplete Dominance neither allele is completely dominant nor completely recessive Heterozygous phenotype is intermediate between the two homozygous phenotypes Homozygous parental phenotypes not seen in F 1 offspring GENETICS

E. Codominance- pg 178 Ex: blood typing in humans – Codominant alleles are neither dominant nor recessive. – The ABO blood types result from codominant alleles. GENETICS

D. Polygentic Traits– p. 198 EX: eye color. Order of dominance: brown > green > blue. GENETICS

GENETICS

Red-green colorblindness - GENETICS

GENETICS

Linkage maps- pg. 203 The closer together two genes are, the more likely they will be inherited together. Cross-over frequencies are related to distances between genes. Linkage maps show the relative locations of genes. GENETICS

V. Pedigrees – p. 207 GENETICS

A. rules 1. males square 2. females circle 3. horizontal line= marriage 4. vertical line= offspring 5. fully shaded= expressed trait 6. half shaded = carrier of trait 7. empty shape= not present GENETICS

GENETICS

VII. Karyotype A. Sex chromosomes B. Autosomal chromosomes GENETICS

VI. Genetic Disorders/Diseases – p. 180 GENETICS

A. Caused by gene mutations – 1. happen during DNA’s replication process 2. occur rarely in nature due to the enzymatic self checking system of DNA during replication. GENETICS

3. Most mutations have provided genetic diversity in species, and some can produce interesting phenotypes !!! GENETICS

4. may occur spontaneously in parent’s or unborn child’s DNA – Dwarfism GENETICS

5. Nondisjunction- GENETICS

B. Mutations may be caused by an outside factor called a mutagen 1. everyone is vulnerable if exposed over a period of time, especially during developmental stages or growth stages GENETICS

EX: carcinogens are mutagenic- GENETICS