Chromosome - Genome.gov
A chromosome is an organized package of DNA found in the nucleus of the cell. Different organisms have different numbers of chromosomes. Humans have 23 pairs of chromosomes--22 pairs of numbered chromosomes, called autosomes, and one pair of sex chromosomes, X and Y.
Chromosome | Definition of Chromosome by Merriam-Webster
Chromosome definition is - any of the rod-shaped or threadlike DNA-containing structures of cellular organisms that are located in the nucleus of eukaryotes, are usually ring-shaped in prokaryotes (such as bacteria), and contain all or most of the genes of the organism; also : the genetic material of a virus.
What is a chromosome?: MedlinePlus Genetics
Each chromosome has a constriction point called the centromere, which divides the chromosome into two sections, or “arms.” The short arm of the chromosome is labeled the “p arm.” The long arm of the chromosome is labeled the “q arm.” The location of the centromere on each chromosome gives the chromosome its characteristic shape, and ...
Chromosome Map - Genes and Disease - NCBI Bookshelf
Chromosome 1 is the largest and is over three times bigger than chromosome 22. The 23rd pair of chromosomes are two special chromosomes, X and Y, that determine our sex. Females have a pair of X chromosomes (46, XX), whereas males have one X and one Y chromosomes (46, XY). Chromosomes are made of DNA, and genes are special units of chromosomal DNA.
Chromosome Abnormalities Fact Sheet - Genome.gov
Chromosome abnormalities can be numerical or structural. A numerical abnormality mean an individual is either missing one of the chromosomes from a pair or has more than two chromosomes instead of a pair. A structural abnormality means the chromosome's structure has been altered in one of several ways.
How Chromosome Mutations Occur - ThoughtCo
A chromosome mutation is an unpredictable change that occurs in a chromosome.These changes are most often brought on by problems that occur during meiosis (division process of gametes) or by mutagens (chemicals, radiation, etc.).Chromosome mutations can result in changes in the number of chromosomes in a cell or changes in the structure of a chromosome.
Chromosome 21: MedlinePlus Genetics
Chromosome 21 is the smallest human chromosome, spanning about 48 million base pairs (the building blocks of DNA) and representing 1.5 to 2 percent of the total DNA in cells. Learn about health implications of genetic changes.
Chromosome Disorder Outreach Inc | chromosome disorder ...
Chromosome Disorder Outreach, Inc is a non-profit organization. Founded, supported, and run by parents just like you, for over 29 years CDO has been supporting those born with rare chromosome and gene mutation disorders.
How to Create a Chromosome Map - The Biology Corner
This map shows chromosome #2 of Drosophila melanogaster. The distance between the genes can be written as a percentage or as a MAP UNIT. The gene for body color and and wing size are 17 map units apart. Sample Problem: Given the crossover frequency of each of the genes on the chart, construct a chromosome map.
Variations | The Association for X and Y Chromosome Variations
The Association for X and Y Chromosome Variations (AXYS) is dedicated to addressing the needs of those affected by one or more extra X and/or Y chromosomes. We are focused on sharing knowledge, offering support, and initiating action to help improve lives of individuals and families.