* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download LN 11Variation in Chromosome Number and Structure
Human genome wikipedia , lookup
Genome evolution wikipedia , lookup
Biology and sexual orientation wikipedia , lookup
Genomic library wikipedia , lookup
Medical genetics wikipedia , lookup
DNA supercoil wikipedia , lookup
Comparative genomic hybridization wikipedia , lookup
Polymorphism (biology) wikipedia , lookup
Designer baby wikipedia , lookup
Genomic imprinting wikipedia , lookup
Koinophilia wikipedia , lookup
Saethre–Chotzen syndrome wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Epigenetics of human development wikipedia , lookup
Polycomb Group Proteins and Cancer wikipedia , lookup
Gene expression programming wikipedia , lookup
Hybrid (biology) wikipedia , lookup
Segmental Duplication on the Human Y Chromosome wikipedia , lookup
Microevolution wikipedia , lookup
Genome (book) wikipedia , lookup
Skewed X-inactivation wikipedia , lookup
Y chromosome wikipedia , lookup
X-inactivation wikipedia , lookup
Variation in Chromosome Number and Structure Objectives: After completing this section, students should: 1. be familiar with basic chromosome morphology. 2. describe ways in identifying and distinguishing chromosomes. 3. understand how changes in chromosome number arise, as well as how such changes lead to genetic defects. 4. be able to distinguish between four major types of chromosome structural aberrations: (deletions, duplications, inversions, translocations). Key Terms: karyotype centromere telocentric acrocentric metacentric satellite histones dicentric deletion duplication inversion translocation polyploidy (auto- and allo-) trisomy nondisjunction Online Lesson(s): None haploid tetraploid cytogenetics Chromosome Morphology Karotype = Morphology = Morphology is based on: 1) 2) 3) 4) Names for describing chromosomes with different centromere positions: Metacentric Acrocentric Telocentric Dicentric Chromosome banding patterns are produced by: Evolutionary conservation of chromosomes: Variation in Chromosome Number and Structure Normal Pattern studies so far… 1) Each chromosome represented once in gametes twice in zygotes 2) Each gene at a specific locus, the loci on a chromosome in a constant and definite linear order. Now we will study changes in the regular patterns. Types of Chromosome Changes 1) Structural changes / Modifications within a chromosome: Inversions: Translocations: 2) Modifications in amount of chromosomes Sets______________________ 1…. Haploid 2…. Diploid 3…. 4…. 6…. 8…. Single_____________________ 2n – 1 ---- Monosomic 2n + 1 ---- Trisomic 2n= n= Autopolyploids Chromosomes Replicate: Diploid 2n = 4 Chromatids separate but cell does not divide Resulting Cell: Autotetraploid 2n = 8 2n + 2n = 4 + 4 Polyploidy Widespread in the plant kingdom, rare in animals Why? Polyploid plant species: Diploid Alfalfa 2n = 16 Wheat Oats Triticale Alfalfa Switchgrass Potato Cotton Coffee Banana Iris Cultivated Alfalfa 2n = _______ __________ploid