Chromosomes


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Related to Chromosomes: Human chromosomes

Chromosomes

Spaghetti-like structures located within the nucleus (or central portion) of each cell. Chromosomes contain the genetic information necessary to direct the development and functioning of all cells and systems in the body. They pass on hereditary traits from parents to child (like eye color) and determine whether the child will be male or female.

chromosomes

carriers of genetic material in the nucleus of body cells. Each consists mainly of an elongated macromolecule of deoxyribonucleic acid (DNA). In human cells there are 23 pairs of chromosomes, each with a 'string' of hundreds to thousands of genes; one of each pair is derived from the germ cell (ovum or sperm) of each parent. One of the pairs are the sex chromosomes, known as 'XX' in the female, 'XY' in the male; splitting of the pairs in the formation of the germ cells in the gonads provides either an X or a Y chromosome in each sperm, so that combination with an X at fertilization determines the gender of the offspring.

chromosomes

48 gene-carrying intranuclear structures arranged as 24 pairs (23 identical pairs and one non-matched pair of sex chromosomes; male sex chromosome has 'X' and 'Y' components [XY]; female sex chromosome has two 'X' components [XX]); each pair of chromosomes reproduces itself during mitosis so that daughter cells each receive a full complement of 24 chromosome pairs; undergo reduction division during meiosis (i.e. ova or sperm formation) and each germ cell has only 24 single chromosomes (i.e. one chromosome from each of the 23 paired chromosomes, one chromosome from the dissimilar pair, as either an 'X' or a 'Y' chromosome; following fusion of ovum (X or X) with sperm (X or Y), the fertilized egg carries a full complement of 24 pairs of chromosomes, and the sex of the individual is determined at conception (XX or XY)

chromosomes (krō´məsōms),

n the small, dark-staining, and more or less rod-shaped bodies situated in the nucleus of a cell. At the time of cell division, chromosomes divide and distribute equally to the daughter cells. They contain genes arranged along their length. The number of chromosomes in the somatic cells of an individual is constant (the diploid number), whereas just half this number (the haploid number) appears in germ cells.
chromosome aberration,
n a rearrangement of chromosome parts as a result of breakage and reunion of broken ends.
References in periodicals archive ?
Losing the Y chromosome in blood cells may bring on cancer and shorten men's lives, new research suggests.
The international research team discovered the potential for substituting the malfunctioning ring chromosome with an appropriately functioning one during reprogramming of patient cells into induced pluripotent stem cells (iPSCs).
Some mammals have already lost their Y chromosome, though they still have males and females and reproduce normally.
University of Arizona geneticists have discovered the oldest known genetic branch of the human Y chromosome -- the hereditary factor determining male sex.
Panel B shows the normal and variant chromosomes 9 in some of the cultured cells of the proband; these cells comprised approximately 6% of 70 cells that were examined: panels (i) one normal chromosome 9 and one ring 9, (ii) one normal chromosome 9 and one broken ring 9, (iii) one normal chromosome 9 and a loss of the ring 9, and (iv) one normal chromosome 9 and one "double ring 9".
Of the many metaphase plates photographed, 65 well-spread metaphase plates on which chromosomes could be precisely counted were selected, and the chromosomes were counted.
Agmatoploidy contrasts with strict or quantitative aneuploidy, which refers to chromosome number changes due to duplication of single chromosomes; polyploidy, which refers to duplications of whole sets of chromosomes; and dysploidy, which is a general term for chromosome number changes by any mechanism that involve only a subset of an organism's chromosomes (Love et al.
Chromosomal aberrations: Aberrations are changes encountered in the chromosomes during cell division.
For this reason, recent studies have attempted to utilize the paternally inherited Y chromosome as well as biparentally inherited autosomal genetic markers to study the relatedness and histories of populations.
The remaining 23 chromosomes pair up with the egg's 23 chromosomes, resulting in the formation of an embryo with half its genes coming from each parent.
Because fruit flies have relatively large, easy-to-see chromosomes and multiply so quickly, scientists have long used them to track genetic processes.
Chromosome 22, a hot spot for human disease, yielded a few more of its secrets to genetics researchers at The Children's Hospital of Philadelphia who analyzed details of the chromosome's structure.