chapter 6 notes

chapter 6 notes - Chapter 6"Chromosome Mutations Variation...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 6 ”Chromosome Mutations: Variation in Number and Arrangement” Genetic information of diploid organisms is delicately balanced in both content and location within the genome. Chromosome mutation, a change in chromosome number or in the arrangement of a chromosome region within the genome, often results in phenotypic variation of disruption of development of an organism. Because the chromosome is the unit of transmission in meiosis, such variations can be passed to offspring in a predictable manner, resulting in many unique genetic outcomes. 6.1 Variation in chromosome number 115 6.2-6.4 Anueploidy and Euploidy 115-120 6.5 Polyploidy and its origins 120-122 6.6-6.10 Variations in chromosome structure 122-12 6. 1 Variation in Chromosome Number and Structure Chromosome aberrations, chromosomal aberrations are the result of changes in physical structure or number of chromosomes of an organism Notation: 2n = 2 complete sets of chromosomes in a diploid organism 1. Variation in Chromosome Number Variations in total number of chromosomes A. Aneuploidy - Unbalanced chromosome number, 2n + 1 or 2n - 1 B. Euploidy - -When two or more sets of the haploid complement of chromosomes are present 2. Variation in Chromosome Structure Structural variations within chromosomes Duplications, deletions, inversions, translocations 6.2 Variation in Chromosome Number A. Aneuploidy, v ariation in single chromosome complement -having more or less than a complete set of chromosomes -when an organism gains or losses one or more chromosome(s) Trisomy- when and organism has one extra chromosome 2n + 1 Monosomy- when and organism has one missing chromosome, 2n - 1
Background image of page 1

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

View Full Document Right Arrow Icon
Origin of Aneuploidy = Nondisjunction during meiosis Nondisjunction can occur during both Anaphase I or II of meiosis -first division nondisjunction -second division nondisjunction
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 6

chapter 6 notes - Chapter 6"Chromosome Mutations Variation...

This preview shows document pages 1 - 3. Sign up to view the full document.

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