Presentation on theme: "Table of Contents Human Inheritance Human Genetic Disorders"— Presentation transcript:
1 Table of Contents Human Inheritance Human Genetic Disorders Advances in Genetics
2 Patterns of Human Inheritance Single genes with two allelesEx: widow’s pickFigure 2 Punnett Square
3 Patterns of Human Inheritance Single genes with multiple allelesEx: Inheritance of Blood TypeBlood type is determined by a single gene with three alleles.fig3/146
4 Patterns of Human Inheritance Traits controlled by many genesEx: human heightDiscovery activity/p144
5 The Sex Chromosomes - Human Inheritance The sex chromosomes carry genes that determine whether a person is male or female. They also carry genes that determine other traits.
6 The Sex chromosomes Sex-linked genes- genes on the X and Y chromosomes not always the sameCan have dominant and recessive allelesBecause males have only one X chromosome, male are more likely to have a sex linked trait that is controlled by recessive alleles.Female -2XMale 1X, 1Y
7 Colorblindness Punnett Square - Human InheritanceColorblindness Punnett SquareRed-green colorblindness is a sex-linked trait. A girl who receives only one recessive allele (written Xc) for red-green colorblindness will not have the trait. However, a boy who receives one recessive allele will be colorblind.
8 Identifying Main Ideas - Human InheritanceIdentifying Main IdeasAs you read the section “Patterns of Human Inheritance,” write the main idea in a graphic organizer. Then write three supporting details that further explain the main idea.Main IdeaHuman traits are controlled by single genes with two alleles, single genes with multiple alleles, and multiple genes.DetailDetailDetailHuman traits controlled by single genes with two alleles have two distinctly different phenotypes.Though a single gene can have multiple alleles, a person can carry only two of these alleles.Multiple genes that control a trait act together to produce a single trait with a large number of phenotypes.
9 The effect of environment Many of a person’s characteristics are determined by an interaction between genes and the environment
10 Click the SciLinks button for links on genetics. - Human InheritanceLinks on GeneticsClick the SciLinks button for links on genetics.
12 Human Genetic Disorders Genetic disorder- abnormal condition that a person inherits through genes or chromosomesCauses:Mutations in the DNA of genesChanges in the structure of chromosomsChanges in the number of chromosomes
13 Human Genetic Disorders Cystic Fibrosis- body produces abnormally thick mucus in the lungs or intestinesCause by a recessive allele on one chromosome as a result of a mutation in which three bases are removed from a DNA molecule
14 Human Genetic Disorders Sickle –Cell DiseaseAffects hemoglobin, a protein in the red blood cells that carries oxygen; cells clog blood vesselsThe allele is codominant with normal alleleA person with two sickle cell alleles will have the disease
15 Human Genetic Disorders HemophiliaPerson’s blood clots very slowly or nor at allCaused by a recessive allele on the X chromosomeSex-linked disorder/occurs more in male than in females
16 Human Genetic Disorders Down SyndromeA person’s cell have an extra copy of chromosome 21 ( 3 chromosomes)Occurs when chromosomes fail to separate properly during meiosisEffect: some degree of mental retardation; heart defects
17 A Pedigree - Human Genetic Disorders A pedigree is a chart or “family tree” that tracks which members of a family have a particular trait.
18 A Hemophilia Pedigree - Human Genetic Disorders The pedigree shows the inheritance of hemophilia, a sex-linked disorder in a family.
19 Managing Genetic Disorders Karyotypes- picture of all the chromosomes in a cellGenetic counseling- understand the chances of having a child with a particular genetic disorderDealing with genetic disorders
20 Pedigree Activity - Human Genetic Disorders Click the Active Art button to open a browser window and access Active Art about pedigrees.
21 Comparing and Contrasting - Human Genetic DisordersComparing and ContrastingAs you read, compare and contrast the types of genetic disorders by completing a table like the one below.DisorderDescriptionCauseCystic fibrosisBody produces abnormally thick mucus.Recessive allele due to removal of three DNA basesSickle-cell diseaseRed blood cells are sickle-shaped and have reduced ability to hold oxygen.Codominant alleleHemophiliaBlood clots slowly or not at all.Recessive allele on X chromosomeDown SyndromeMental retardation and heart defectsAn extra copy of chromosome 21
22 Click the Video button to watch a movie about sickle-cell disease. - Human Genetic DisordersSickle-Cell DiseaseClick the Video button to watch a movie about sickle-cell disease.
24 Advances in GeneticsSelective Breeding: selecting organisms with desired traits to be parents of the next generationInbreeding: crossing two individuals that have the similarCharacteristicsHybridization: crossing two genetically different individuals;the offspring will have the best traits from both parents
25 Changing Rice Production - Advances in GeneticsChanging Rice ProductionThe graph shows how worldwide rice production changed between 1965 and New, hybrid varieties of rice plants are one factor that has affected the amount of rice produced.
26 Changing Rice Production - Advances in GeneticsChanging Rice ProductionReading Graphs:According to the graph, how did rice production change between 1965 and 2000?Rice production increased.
27 Changing Rice Production - Advances in GeneticsChanging Rice ProductionReading Graphs:How many metric tons of rice per hectare were produced in 1965? How many were produced in 2000?2 in 1965; 4 in 2000
28 Changing Rice Production - Advances in GeneticsChanging Rice ProductionCalculating:Calculate the approximate difference between rice production in 1965 and 2000.2 metric tons/hectare
29 Changing Rice Production - Advances in GeneticsChanging Rice ProductionDeveloping Hypotheses:What factors besides new varieties of plants might help account for the difference in rice production between 1965 and 2000?Possible answer: fertilizers and improved harvesting methods
30 CloningOrganism that have the exact genes as the organism from which it was producedIs cloning ethical?
31 Genetic Engineering - Advances in Genetics Scientists use genetic engineering to create bacterial cells that produce important human proteins such as insulin.
32 Asking Questions - Advances in Genetics Before you read, preview the red headings. In a graphic organizer like the one below, ask a question for each heading. As you read, write answers to your questions.QuestionsAnswersWhat is selective breeding?Selective breeding is the process of selecting organisms with desired traits to be parents of the next generation.Why are organisms cloned?To produce offspring with desired traitsWhat is genetic engineering?A process in which genes from one organism are transferred into the DNA of another organismWhat advance has helped us learn about human genetics?The Human Genome Project
33 Links on Genetic Engineering - Advances in GeneticsLinks on Genetic EngineeringClick the SciLinks button for links on genetic engineering.
34 Click the Video button to watch a movie about selective breeding. - Advances in GeneticsSelective BreedingClick the Video button to watch a movie about selective breeding.