Click on a lesson name to select. Section 1: Basic Patterns of Human Inheritance Section 2: Complex Patterns of Inheritance Section 3: Chromosomes and Human Heredity Complex Inheritance and Human Heredity

Basic Patterns of Human Inheritance Complex Inheritance and Human Heredity Section 1 I. Recessive Genetic Disorders (more common)  A recessive trait is expressed when the individual is homozygous recessive for the trait.

Complex Inheritance and Human Heredity A. Cystic Fibrosis (common in caucasians)  Affects the mucus-producing glands, digestive enzymes, and sweat glands  Chloride ions are not absorbed into the cells of a person with cystic fibrosis but are excreted in the sweat.  Without sufficient chloride ions in the cells, a thick mucus is secreted. Basic Patterns of Human Inheritance Section 1

Complex Inheritance and Human Heredity B. Albinism  Caused by altered genes, resulting in the absence of the skin pigment melanin in hair and eyes  White hair  Very pale skin  Pink pupils Basic Patterns of Human Inheritance Section 1

Complex Inheritance and Human Heredity C. Tay-Sachs Disease (common in Jewish)  Death by age 5  Caused by the absence of the enzymes responsible for breaking down fatty acids called gangliosides  Gangliosides accumulate in the brain, inflating brain nerve cells and causing mental deterioration. Basic Patterns of Human Inheritance Section 1

Complex Inheritance and Human Heredity D. Galactosemia  Recessive genetic disorder characterized by the inability of the body to digest galactose and glucose.  Avoid milk products. Basic Patterns of Human Inheritance Section 1

Complex Inheritance and Human Heredity II. Dominant Genetic Disorders  Only need 1 dominant allele.  A. Huntington’s disease affects the nervous system. *Late onset!*  B. Achondroplasia is a genetic condition that causes small body size and limbs that are comparatively short. (“Dwarfism”) Basic Patterns of Human Inheritance Section 1

Complex Inheritance and Human Heredity Basic Patterns of Human Inheritance Section 1

Complex Inheritance and Human Heredity III. Pedigrees  A diagram that traces the inheritance of a particular trait through several generations Basic Patterns of Human Inheritance Section 1

Complex Inheritance and Human Heredity A. Inferring Genotypes  Knowing physical traits can determine what genes an individual is most likely to have. B. Predicting Disorders  Record keeping helps scientists use pedigree analysis to study inheritance patterns, determine phenotypes, and ascertain genotypes. Basic Patterns of Human Inheritance Section 1

1.A 2.B 3.C 4.D FQ 1 Complex Inheritance and Human Heredity Chapter A.It appears at birth and runs in families. B.It is linked to an enzyme deficiency. C.It continues throughout a patient’s life, affecting bones and joints. D.It is caused by acid excretion and results in black urine. Which of Dr. Garrod’s observations about alkaptonuria was most critical to his determination that it is a genetic disorder? Section 1 Formative Questions

1.A 2.B 3.C 4.D FQ 2 Complex Inheritance and Human Heredity Chapter A. DD B. Dd C. dd D. dE Which is the genotype of a person who is a carrier for a recessive genetic disorder? Section 1 Formative Questions

1.A 2.B 3.C 4.D FQ 3 Complex Inheritance and Human Heredity Chapter Section 1 Formative Questions A. at least one parent is a carrier B. both parents are carriers C. both parents are homozygous recessive D. at least one parent is homozygous dominant Albinism is a recessive condition. If an albino squirrel is born to parents that both have normal fur color, what can you conclude about the genotype of the parents?

Complex Patterns of Inheritance Complex Inheritance and Human Heredity I. Incomplete Dominance  The heterozygous phenotype is an intermediate phenotype between the two homozygous phenotypes. Section 2

Complex Inheritance and Human Heredity II. Codominance  Both alleles are expressed in the heterozygous condition. Complex Patterns of Inheritance Section 2  Sickle-cell disease is one example.

Complex Inheritance and Human Heredity Sickle-cell Disease  Changes in hemoglobin cause red blood cells to change to a sickle shape.  People who are heterozygous for the trait have both normal and sickle-shaped cells. Sickle cell Normal red blood cell 7766x Complex Patterns of Inheritance Section 2

Complex Inheritance and Human Heredity III. Multiple Alleles  A. Human blood  Blood groups in humans  ABO blood groups have three forms of alleles.  (codominance and multiple alleles Complex Patterns of Inheritance Section 2

Complex Inheritance and Human Heredity B. Coat Color of Rabbits  Multiple alleles can demonstrate a hierarchy of dominance.  In rabbits, four alleles code for coat color: C (C=full color), c ch, c h, and c (recessive, albino). Complex Patterns of Inheritance Section 2

Complex Inheritance and Human Heredity IV. Epistasis  Variety is the result of one allele hiding the effects of another allele.  Coat color  E=dark pigmentB=how dark  EEBB and EeBb =black  EEbb or Eebb =brown  eebb, eeBb, eeBB= yellow (e masks B) Complex Patterns of Inheritance Section 2

Complex Inheritance and Human Heredity V. Sex Determination  A. Sex chromosomes determine an individual’s gender.  All cells in the body except sex contain 46 chromosomes  Sex chromosome (#22) and last is gender Complex Patterns of Inheritance Section 2

Gender is determined by combination of sex chromosomes in the egg and sperm. The shapes are different so little to no cross over.

Complex Inheritance and Human Heredity B. Dosage Compensation  The X chromosome carries a variety of genes that are necessary for the development of both females and males.  The Y chromosome mainly has genes that relate to the development of male characteristics.  In females, one X chromosome is inactivated in each cell. The inactivated X chromosome is visible in stained cells as a Barr body. Complex Patterns of Inheritance Section 2

Complex Inheritance and Human Heredity VI. Sex-Linked Traits  Genes located on the X chromosome  males only have 1 X-affected by recessive more than females  Red-green color blindness  Some traits seem sex linked but are not (male baldness is dom in males, rec in females) Complex Patterns of Inheritance Section 2 Sex-Linked Traits

Complex Inheritance and Human Heredity VII. Polygenic Traits  Polygenic traits arise from the interaction of multiple pairs of genes. Complex Patterns of Inheritance Section 2

Complex Inheritance and Human Heredity VIII. Environmental Influences  Environmental factors influence an organism’s phenotype  Diet and exercise  Sunlight and water  Temperature Complex Patterns of Inheritance Section 2

Complex Inheritance and Human Heredity IX. Twin Studies  Helps scientists separate genetic contributions from environmental contributions  Traits that appear frequently in identical twins are at least partially controlled by heredity.  Traits expressed differently in identical twins are strongly influenced by environment. Complex Patterns of Inheritance Section 2

1.A 2.B 3.C 4.D FQ 4 Complex Inheritance and Human Heredity Chapter A. dosage compensation B. incomplete dominance C. multiple alleles D. sex-linked When a homozygous male animal with black fur is crossed with a homozygous female with white fur, they have offspring with gray fur. What type of inheritance does this represent? Section 2 Formative Questions

1.A 2.B 3.C 4.D FQ 5 Complex Inheritance and Human Heredity Chapter Section 2 Formative Questions A. autosomes B. Barr bodies C. monosomes D. sex chromosomes Of the 23 pairs of chromosomes in human cells, one pair is the _______.

1.A 2.B 3.C 4.D FQ 6 Complex Inheritance and Human Heredity Chapter Section 2 Formative Questions A. blood type B. color blindness C. hemophilia D. skin color Which is an example of a polygenic trait?

 Karyotype—micrograph in which the pairs of homologous chromosomes are arranged in decreasing size. Chromosomes and Human Heredity Complex Inheritance and Human Heredity I. Karyotype Studies  Images of chromosomes stained during metaphase  Chromosomes are arranged in decreasing size to produce a micrograph. Section 3

Complex Inheritance and Human Heredity II. Telomeres  Telomere caps consist of DNA associated with proteins.  Serves a protective function for the structure of the chromosome Chromosomes and Human Heredity Section 3

Complex Inheritance and Human Heredity III. Nondisjunction  Cell division during which sister chromatids fail to separate properly  If one sex cell gets an extra, another gets one less. Random which is fertilized.  Down syndrome, also called trisomy 21 Chromosomes and Human Heredity Section 3

Nondisjunction in sex chromosomes –XX =normalXY= normal –X0=TurnersXXY=Klinefelters –XXX=nearly normalXYY=nearly normal OY=fatal before birth Turners-infertile, thicker neck Klinefelters-may have some female characteristics

IV. Fetal testing –Amniocentesis=chromosome abnormalities and defects –Chorionic villus sampling=genetic defects and chromosome abnormalities –Fetal blood sample=genetic abnormalities, fetal blood problems, can give medications before birth

1.A 2.B 3.C 4.D FQ 7 Complex Inheritance and Human Heredity Chapter A. The blood type of an individual. B. The locations of genes on a chromosome. C. The cell’s chromosomes arranged in order. D. The phenotype of individuals in a pedigree. What does a karyotype show? Section 3 Formative Questions

1.A 2.B 3.C 4.D FQ 9 Complex Inheritance and Human Heredity Chapter Section 3 Formative Questions A. Down syndrome B. Klinefelter’s syndrome C. Tay-Sachs syndrome D. Turner’s syndrome What condition occurs when a person’s cells have an extra copy of chromosome 21?

Complex Inheritance and Human Heredity Chapter Resource Menu Chapter Diagnostic Questions Formative Test Questions Chapter Assessment Questions Standardized Test Practice connected.mcgraw-hill.com Glencoe Biology Transparencies Image Bank Vocabulary Animation Click on a hyperlink to view the corresponding feature. Chapter

1.A 2.B 3.C 4.D CDQ 1 A. albinism B. cystic fibrosis C. galactosemia D. Tay-Sachs Identify the disease characterized by the absence of melanin. Complex Inheritance and Human Heredity Chapter Chapter Diagnostic Questions

1.A 2.B 3.C 4.D CDQ 2 Complex Inheritance and Human Heredity Chapter Chapter Diagnostic Questions A. excessive mucus production B. an enlarged liver C. a cherry-red spot on the back of the eye D. vision problems An individual with Tay-Sachs disease would be identified by which symptom?

1.A 2.B 3.C 4.D CDQ 3 Complex Inheritance and Human Heredity Chapter Chapter Diagnostic Questions Under what circumstances will a recessive trait be expressed? A. A recessive allele is passed on by both parents. B. One parent passes on the recessive allele. C. The individual is heterozygous for the trait. D. There is a mutation in the dominant gene.

1.A 2.B 3.C 4.D CAQ 1 Complex Inheritance and Human Heredity Chapter A. 1 and 2 are siblings B. 1 and 2 are parents C. 1 and 2 are offspring D. 1 and 2 are carriers What does the top horizontal line between numbers 1 and 2 in the figure indicate? Chapter Assessment Questions

1.A 2.B 3.C 4.D CAQ 2 Complex Inheritance and Human Heredity Chapter Chapter Assessment Questions A. I A B. I O C. I B D. i Which is not an allele in the ABO blood group?

1.A 2.B 3.C 4.D CAQ 3 Complex Inheritance and Human Heredity Chapter Chapter Assessment Questions A. one less chromosome on pair 12 B. one extra chromosome on pair 21 C. one less chromosome on pair 21 D. one extra chromosome on pair 12 Down Syndrome results from what change in chromosomes?

1.A 2.B 3.C STP 1 Complex Inheritance and Human Heredity Chapter A. heterozygous B. homozygous dominant C. homozygous recessive If a genetic disorder is caused by a dominant allele, what is the genotype of those who do not have the disorder? Standardized Test Practice

1.A 2.B 3.C STP 2 Complex Inheritance and Human Heredity Chapter Standardized Test Practice A. RR B. Rr C. rr Analyze this pedigree showing the inheritance of a dominant genetic disorder. Which would be the genotype of the first generation father?

1.A 2.B 3.C 4.D STP 3 Complex Inheritance and Human Heredity Chapter Standardized Test Practice A. codominance B. dosage compensation C. epistasis D. sex-linked Shorthorn cattle have an allele for both red and white hair. When a red-haired cow is crossed with a white-haired bull, their calf has both red and white hairs scattered over its body. What type of inheritance does this represent?

1.A 2.B 3.C 4.D STP 4 Complex Inheritance and Human Heredity Chapter Standardized Test Practice A. Males have only one X chromosome. B. Males have two X chromosomes. C. Males have only one Y chromosome. D. The traits are located on the Y chromosomes. Why are males affected by recessive sex-linked traits more often than are females?

1.A 2.B 3.C 4.D STP 5 Complex Inheritance and Human Heredity Chapter Standardized Test Practice A. 25% B. 50% C. 75% D. 100% A carrier of hemophilia and her husband, who is unaffected by the condition, are expecting a son. What is the probability that their son will have hemophilia?

Complex Inheritance and Human Heredity Chapter Glencoe Biology Transparencies

Complex Inheritance and Human Heredity Chapter Image Bank

carrier pedigree Complex Inheritance and Human Heredity Section 1 Vocabulary Section 1

incomplete dominance codominance multiple alleles epistasis sex chromosome autosome sex-linked trait polygenic trait Complex Inheritance and Human Heredity Section 2 Vocabulary Section 2

karyotype telomere nondisjunction Complex Inheritance and Human Heredity Section 3 Vocabulary Section 3

Complex Inheritance and Human Heredity Chapter Animation  Visualizing Nondisjunction Visualizing Nondisjunction

Complex Inheritance and Human Heredity Chapter