Study of chromosomes in human by karyotype testing and preparation of karyotype for the analysis of genetic & birth disorders, cancer and sex determination. Chemical composition of chromosomes | biology article shared by advertisements: read this article to get information about the chemical composition of chromosomes the major chemical components of the chromosome are dna, rna (nucleic acids), and proteins (histones and nonhistones.
Standard cytogenetic examination requires analysis of chromosomes on the stage of metaphase (metaphase analysis) at this stage of cell division all chromosomes became clearly visible structures all chromosomes may be recognized by their size, position of a centromere and characteristic pattern of dark and light bands, which can be seen after special staining. Chromosome analysis or karyotyping is a test that evaluates the number and structure of a person's chromosomes in order to detect abnormalities chromosomes are thread-like structures within each cell nucleus and contain the body's genetic blueprint.
The karyotype za karyotype is a pattern or picture of chromosomes zthe chromosomes are paired and arranged according to size zeach chromosome is paired with its homologous chromosome – its exact match in size and structure, though the homologous chromosomes may carry different alleles of the same gene. Female with 46 chromosomes with a deletion of chromosome 14 on the long arm (q) at band 23 46,xy,dup(14)(q22q25) male with 46 chromosomes with a duplication of chromosome 14 on the long arm (q) involving bands 22 to 25 46,xx,r(7)(p22q36) female with 46 chromosomes with a 7 chromosome ring. The quantity of dna in a cell is directly proportional to the number of chromosomes in the nucleus it is the primary genetic material since the dna content and chromosome number are related and it is only restricted to the nucleus and transmitted to the daughter cells during cell division.
Cells for chromosome analysis can come from a blood sample, from inside a bone (bone marrow sample), from a swab of cells taken from inside your mouth, or from a sample of your skin or hair cells can also be taken from the fluid that surrounds a baby inside a mother's womb this is called amniocentesis. The chromosomal makeup of cells can be studied with various methods the most common technique, karyotype analysis, uses chromosomes that are fixed onto slides.
Cytogenetics is a branch of genetics that is concerned with how the chromosomes relate to cell behaviour, particularly to their behaviour during mitosis and meiosis techniques used include karyotyping, analysis of g-banded chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescent in situ hybridization and comparative genomic hybridization.
Chromosome analysis is the microscopic examination of chromosomes in dividing cells such analysis can detect changes in chromosomal number and structure deletions (eg, partial monosomy), duplications (eg, partial trisomy), and structural abnormalities such as translocations, inversions, and rings can be detected.