PPT-Sex – linked Traits

Genes for these traits are located only on the X chromosome NOT on the Y chromosome X linked alleles always show up in males whether dominant or recessive because males have only . Homework #2 is due on Monday in lecture.. Change to 1b. . Do not calculate a . c. 2. value. .. Just calculate the . expected. phenotypic ratios if the genes for brown-ness and disease-resistance are actually the same gene (or completely linked). Then, say whether complete linkage is possible given the observed data.. Humans have 46 chromosomes in every cell.. 2 of these chromosomes make us male or female.. Female: XX Male: XY. The Sex Chromosomes:. Has information for male traits.. Few other genes.. The Y chromosome. Essential Question: . How are dominant and recessive sex-linked traits passed onto offspring?. Sex-linked traits are determined by genes on sex-chromosomes.. Most. sex-linked alleles (genes) are carried on the X chromosome. . Kyle . Stutts. . Sam . houston. state . university. Sex-Linked Characteristics. Objectives. Students will be able to:. Comprehend how inheritance plays a role in sex-linked genes. Explain the difference between sex- linked, limited, and influenced inheritance. Complex Inheritance Patterns:. Autosomal v. X-Linked. Pedigree. Family Tree. Genealogy. Inheritance . Diagram. Relates . parents and offspring for numerous generations. Shows relationships between parents, children, grandchildren…. Contents:. Introduction to sex linked inheritance.. Chromosome carries which type of genes?. Three types of traits. Characteristics of sex linkage.. Types of sex linkage.. Sex linked disorders.. Sex linked inheritance :. Kyle . Stutts. . Sam . houston. state . university. Sex-Linked Characteristics. Objectives. Students will be able to:. Comprehend how inheritance plays a role in sex-linked genes. Explain the difference between sex- linked, limited, and influenced inheritance. Part 4. What is a PEDIGREE. A chart used to trace traits throughout a family. Parts of the chart. Circle = females. Squares = males. Half-filled in/Dotted = carrier. Have the gene but do not show signs of it. pg. 258 #11, 14-17, 19 Sex Linkageare controlled by genes located on either the X or Y chromosome. homologous DNA.Human Y : Two copies of each autosomal gene affect phenotype.. Mendel studied autosomal gene traits, like hair texture. . Mendel. ’. s rules of inheritance apply to autosomal genetic disorders.. A heterozygote for a recessive disorder is a carrier. . Stolen and edited from: IMS Dr. Kyle . Stutts. (SHSU) and Brandon . Freel. Objectives. Discuss genetic inheritance.. Investigate principles of inheritance.. Demonstrate how inheritance plays a role in sex-linked genes. Sex-Linked Traits. Traits controlled by a gene found on the sex chromosome. The Y chromosome is shorter than X; therefore, some genes on the X chromosome may be missing from Y. Sex-linked disease is less likely to affect females because they have 2 X chromosomes. Karyotype. Karyotype. – a . picture of . chromosomes. Autosomes. : the first 22 homologous pairs of chromosomes. . Autosomes . are the same for both males and females..  Sex chromosomes. : determines the sex of the individual. . In a plant, long stems are dominant (L) to short stems (l). If a homozygous dominant flower and a homozygous recessive plant are crossed, what would be the phenotypic ratio of their offspring?. Science Fact of the Day.