Cell Division

Ploidy

the number of complete sets of chromosomes in a cell

Diploid

A cell that contains two complete sets of chromosomes, one set inherited from each parent. What most body/somatic cells are.

Haploid

A cell that contains one complete set of chromosomes.

Polyploid

A cell or organism that contains more than two complete sets of chromosomes, such as 3n, 4n, 6n, etc.

Karyotype

complete set of chromosomes in an individual or species, arranged by size, shape, and number

Chromosome

A DNA-containing structure that carries genetic information.

Chromatid

One of the two identical copies of a duplicated chromosome, joined at the centromere.

Chromatin

The less-condensed form of DNA associated with proteins, mainly present during interphase.

Centromere

The constricted region of a chromosome that holds sister chromatids together and serves as the site where the kinetochore forms.

Kinetochore

A protein structure assembled at the centromere where spindle fibers attach during cell division.

p arm

the short arm of a chromosome

q arm

the long arm of a chromosome

Telomere

A repetitive DNA sequence at the ends of chromosomes that protects chromosome ends from degradation and unwanted fusion.

Metacentric

• The centromere is located approximately in the middle, producing two arms of nearly equal length.

• V-shaped during anaphase.

Submetacentric

• The centromere is slightly off-center, producing one shorter arm and one longer arm.

• L-shaped during anaphase.

Acrocentric

• The centromere is located very close to one end, producing a very short p arm and a much longer q arm.

• J-shaped during anaphase.

Telocentric

• The centromere is located at or extremely close to the end, making the chromosome appear to have only one arm.

• I-shaped during anaphase.