Chromosome Shapes: Telocentric, Acrocentric, Submetacentric, Metacentric; P Arm, Q Arm; Cytogenetics; Autosomes vs Sex Chromosomes; Euploidy, Aneuploidy, Polyploidy, Non-Disjunction, Meiosis I & II Errors; Trisomy 13, 18, 21; Turner Syndrome, Klinefelter

Chromosome Shapes: Telocentric, Acrocentric, Submetacentric, Metacentric; P Arm, Q Arm; Cytogenetics; Autosomes vs Sex Chromosomes; Euploidy, Aneuploidy, Polyploidy, Non-Disjunction, Meiosis I & II Errors; Trisomy 13, 18, 21; Turner Syndrome, Klinefelter Syndrome, Triple X, Jacob Syndrome; Cri-du-chat, Wolf-Hirschhorn, DiGeorge Syndrome, Williams Syndrome; Charcot-Marie-Tooth Disease; Chromosomal Translocation: Reciprocal, Robertsonian; BCR-ABL, Philadelphia Chromosome; Chromosomal Inversion: Paracentric, Pericentric; Ring Chromosome 14, Isochromosome; Balanced vs Unbalanced Rearrangements Exam Questions Verified and Provided with A+ Graded Rationales Latest Updated 2026 Chromosome shapes telocentric (not in humans) acrocentric (near the end) submetacentric (b/t middle and end) metacentric (near the middle) p arm vs. q arm short arm (p) long arm (q) the study of chromosomes and their abnormalities Cytogenetics autosomes vs sex chromosomes What chromosome # are they Any chromosome that is not a sex chromosome - chromosomes (1-22) Chromosomes that determine the sex of an individual (XX or XY) - chromosome 23 Fluorescence in situ hybridization (FISH) Chromosome specific DNA segment is labeled with a fluorescent tag = probe - probe will glow under microscope via fluorescence **can detect chromosomal abnormalities Euploidy how many chromosomes in somatic cells? how many chromosomes in gametes? the correct number of chromosomes 2N = 46 chromosomes = somatic cells N = 23 chromosomes = gametes Aneuploidy vs Polyploidy Aneuploidy: Abnormal number of chromosomes - gain or loss Polyploidy: condition in which an organism has extra sets of chromosomes EX: 3N, 4N, etc. Is a loss of an autosome viable? *Autosome: any chromosome that isn't a sex chromosome* Is gain of autosome viable? What three trisomies are viable? NO - spontaneous abortion YES 13, 18, 21 What causes chromosome maldistribution? Does it take place in meiosis or mitosis? NON-DISJUNCTION in Meiosis Nondisjunction can occur during anaphase of mitosis, meiosis I, or meiosis II. Non-disjunction in meiosis I vs. Non-disjunction in Meiosis II Results in all 4 gametes being abnormal *All daughter cells affected* Results in 2 normal gametes and 2 abnormal gametes *Half daughter cells affected * Aneuploidies of Sex Chromosomes: Which chromosome is required for survival X chromosome -If Y is present, phenotype is a male - If more than one X, all but one becomes barr bodies Turner Syndrome (HY/TQ) Need to know chromosome nomenclature! 45, XO - monosomy of X chromosome Characteristics: - short stature - broad chest - webbed neck - ovarian dysgenesis (absence of normal ovaries) - Estrogen deficiency - partial malformation of internal organs Klinefelter syndrome Need to know chromosome nomenclature! Think of Randy who works at Kleinfield Bridal 47, XXY (males)