Acrocentric: A chromosome in which the centromere is located towards one end of the chromosome.

C-banding: It is a technique used to stain centromere or constitutive heterochromatin using Giemsa or fluorescent stains.

Cell Culture: Cell culture involves the removal of cells from an organism and their subsequent growth in a favourable artificial environment.

Centromere: It is a region to which the spindle fibres attach to the chromosome during cell division. It contains a small ring of protein called a kinetochore involved in the movement of chromosomes during mitosis and meiosis.

Chromatid: A chromatid is one-half of the usually paired and parallel strands of a duplicated chromosome composed of a DNA molecule and joined by a single centromere.

Chromosome: It is a thread like structure found in the nucleus containing single strand of DNA tightly coiled on histone proteins.

Chromosome banding: A method of producing transverse bands along the length of chromosomes using specialized staining techniques.

Chromosome number: It is the characteristic number of chromosomes present in each somatic cell of a given species and is constant for a particular species.

Colchicine: It is a pale yellow crystalline alkaloid, derived from members of the plant genus Colchicum that irreversibly binds tubulin and prevents the chromosomes of mitotic cells from entering anaphase.

Cytogenetics: It is the branch of genetics concerned with the study of structure and function of cells, DNA and chromosomes.

Diploid Cells: Refers to those cells that have two sets of chromosomes. In diploid organisms, male and female parents donate one set of chromosomes to form a diploid offspring.

FISH (Fluorescence in situ hybridization): A laboratory technique used to detect and locate DNA sequence on chromosome and allows physical visualization and mapping of specific genes or loci of interest on chromosome or interphase nucleus.

Genome size: It is the total amount of DNA present in haploid set of chromosomes and is typically measured in terms of mass in picograms (abbreviated pg) or less frequently in Daltons or as the total number of nucleotide base pairs.

Genome: A complete set of DNA present in an organism, including both the genes and non-coding sequences. The genome contains the complete information needed to build and maintain that organism.

Haploid Cells: Refers to cells that contain only one complete set of chromosomes for e.g. gametes or sex cells and are usually produced by meiosis.

Homologous chromosomes: Similar set of chromosomes having the same general kind of genes along their length, for e.g. human has 23 pairs of homologues.

Karyotype: It is the arrangement of chromosomes according to a standard classification scheme of descending size, centromere location and banding pattern.

Kinetochore: A protein structure present on centromere to which the spindle fibers are attached during cell division.

Metacentric: A chromosomes having centromere situated medially thus creating two chromosomal arms that are roughly equal in length.

Molecular Cytogenetics: It is the use of combination of techniques used in cytogenetics and molecular biology. It mainly involves use of FISH technique to study metaphase chromosomes or interphase cells.

NOR banding: A technique used to localize nucleoli-organizing regions on chromosomal arms using silver or fluorescent stain.

Polyploidy: Refers to the condition where the cells possess more than two haploid (n) sets of chromosomes for e.g. triploid (3n) and tetraploid cell (4n) cells are polyploid.

Probe: A short DNA/RNA fragment labelled with a fluorescent or hapten molecules used to detect DNA regions/genes (targets) that are complementary to sequence in the probe.

Sex Chromosome: It is one of the two chromosomes that determines sex, so differing in shape and function.

Submetacentric: A chromosome in which the centromere is near the centre but not in the middle, so that two arms are not of equal length.

Telomere: A region of repetitive sequences situated at the terminal end of a chromosome arm.