handout 3.1.11 - 3/1/11 1. Nondisjunction: Failure of...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
1 3/1/11 1. Nondisjunction: Failure of homologues or sister chromatids to separate in meiosis I, meiosis II, or mitosis, thereby resulting in aneuploidies 2. Haploinsufficiency: The inability to produce the normal phenotype via the expression of one functional allele. Thus, to be normal, one must be homozygous (rather than heterozygous) for the functional allele -------------------------------------------------------------------------------------------------------------------------------------------- MUTATIONS: EXTENT OF DNA CHANGE I. Point mutations (one to few bases affected) A. Base substitutions (subs) 1. Transitions (TS) – Purine (R) for R, or pyrimidine (Y) for Y 2. Transversions (TV) – R for Y or vice versa B. Base insertions and deletions (indels) 1. Insertions – Gain of one or a few bases 2. Deletions – Loss of one or a few bases II. Chromosome mutations A. Deletions, deficiencies – Chromosomal region lost B. Duplications – Chromosomal region gained 1. Tandem (adjacent copies) 2. Transpositional (dispersed copies) C. Inversions – Chromosomal region rotated 180 1. Paracentric – Centromere not included in inversion 2. Pericentric – Centromere included in inversion D. Translocations – DNA transfer between nonhomologous chromosomes 1. Reciprocal – Bidirectional exchange between nonhomologous chromosomes 2. Nonreciprocal – Unidirectional transfer between nonhomologous chromosomes III. Aneuploidy – Gain or loss of whole chromosome A. Monosomy – Missing one homologue of a chromosome type (2 n – 1) B. Trisomy – One extra homologue of a chromosome type (2 n + 1) IV. Polyploidy – Gain of extra whole chromosome sets
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 06/08/2011 for the course PCB 3063 taught by Professor Marta during the Spring '08 term at University of Florida.

Page1 / 2

handout 3.1.11 - 3/1/11 1. Nondisjunction: Failure of...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online