BIOLOGY NOTES GENETICS PART 5 PAGES 198 208

BIOLOGY NOTES GENETICS PART 5 PAGES 198 -208, 212 -217

Standards: 5. 6 Use Mendel’s laws of segregation and _____ independent assortment to analyze patterns of inheritance 5. 7 Discuss observed inheritance patterns _____ caused by various modes of inheritance, including dominant, recessive, co-dominant, sex-linked, polygenic, and multiple alleles _____ 5. 14 Analyze how heredity and family history can impact personal health

Essential Question: 1. How do genes influence the variety of organisms that exist?

I. Human Autosomal Disorders Autosome = chromosome pairs 1 -22 which contain genes for characteristics not directly related to the ____ sex of the organism • Autosomal disorders can occur in any chromosomes except the _____ sex chromosomes

1. Albinism 2 recessive alleles • Cause: ________ hair , and eyes • Lack of pigment in skin, _____ light • Skin and eyes are extremely sensitive to _____ 2. Cystic Fibrosis 2 recessive alleles • Cause: _________ respiratory • Excess mucus in _____and digestive tract • Respiratory and pulmonary problems

3. Galactosemia 2 recessive alleles • Cause: _________ galactose which builds • Inability to breakdown _____ up in body liver damage • Mental retardation, eye and _____ 4. Tay-Sachs disease 2 recessive alleles • Cause: ________ • Lipid accumulation in brain cells • Death early in childhood.

5. Huntington’s disease 1 dominant allele • Cause: ________ • Progressive destruction of muscles and nervous system nerves until death • Destruction of muscles and _______ occurs

II. Unique Patterns of Inheritance Mendelian genetics predicts offspring Simple ______ and parents based on alleles that are only dominant or _____. recessive The majority of _____ complex and organisms, however, are more ____ inheritance show unique patterns of ______.

A. Incomplete Dominance = type of inheritance 1 allele is not completely in which __ _____ dominant over another blend between the • the heterozygote is a ______ two alleles (completely different heterozygote)

e. g. flower color in 4 o’clock plants RR = Red RR * WW = RW (pink) RW = Pink WW = White ** since neither allele is more dominant over the other, each allele gets its own letter What type of human traits do you think show incomplete dominance (baby lab)? ** Lip shape, mouth size, size of eyes, eye spacing, hair type, ear size, nose size

B. Multiple Alleles = type of inheritance in which 2 alleles within a genes have more than __ _____ population 2 alleles • each individual can have only ___ e. g. ABO Blood System 3 alleles = IA, IB, and i IAIA = type A blood IAIB = type AB blood IAi = type A blood IBIB = type B blood IBi = type B blood ii = type O blood (no antigens)

* Who would be the universal donor? ii = type O blood * Who would be the universal recepient? IAIB = type AB blood

C. Codominance = type of inheritance in which phenotype both alleles contribute to the _____ express themselves, but not as • both alleles ____ blend a ______ e. g. AB Blood Type, Checkered Chickens, Sickle Cell Anemia IAIA = type A blood (has only A antigens) IBIB = type B blood (has only B antigens) IAIB = type AB blood (has A and B antigens)

e. g. AB Blood Type, Checkered Chickens B = Black b = White Bb = checkered

D. Polygenic Traits = type of inheritance in traits are controlled by more than __ 1 which ______ gene e. g. eye color, hair color, skin color

E. Sex-Linked Genes = type of inheritance in traits are located which genes with particular ______ chromosomes (X or Y) on the sex _______ XY while females are ____ XX • males are ____ X • in males, any trait linked to the ___ expressed even if chromosome will be ______ they are recessive

1. Color-Blindness allele on the ___ X v caused by a recessive ______ chromosome v 1 in 10 males have red-green colorblindness v 1 in 100 females have red-green colorblindness

e. g. XB = normal Xb = colorblind XBXB = normal female X BX b XBY = normal male Xb. Xb = colorblind female Xb. Y = colorblind male

2. Hemophilia allele on the ___ X v caused by a recessive ______ chromosome v 1 in 10, 000 males have the disease v in this disease, blood clotting enzymes are absent _______ v small bruises and cuts may cause excessive _____ bleeding even into death

e. g. What would be the chances of having a Hemophiliac son if XHXh * XHy?

III. Human Heredity A. Karyotype = a chart that shows all pairs of chromosomes in order _______ mitosis when the • taken during _______ chromosomes formed (during prophase) 46 chromosomes that are • humans have ___ 23 pairs organized into ___ type of genes but veach pair has the same _____ alleles may have different _______

v in each pair, one chromosome comes from mom and one from ____ dad _____ 23 rd set of • sex chromosomes = the _____ gender of chromosomes that determines the _______ the human XX for females XY for males and ____ v____

D. Sex Chromosomal Disorders • Nondisjunction = during meiosis, homologous chromosomes fail to separate ______ few meaning gametes with too ______ many or too ____ chromosomes

1. Down’s Syndrome trisomy 21 because there v also known as ____ 3 #21 chromosomes are __ vresults in severe mental retardation 2. Klinefelter’s Syndrome (XXY) X chromosome v have an extra ___ vprevents individuals from reproducing

3. Turner’s Syndrome (XO) 1 sex chromosome which is an v have only ___ X ___ v unable to develop sex organs at all