Chromosomes

Haploid Cell

A cell containing only one set of chromosomes (n), or one chromosome from each homologous pair

Diploid Cell

A cell containing two sets of chromosomes (2n), one set inherited from each parent, or a cell containing both chromosomes of each homologous pair

Karyotype

A picture that shows the number and appearance of an individuals chromosomes

Histone

A protein that assists in coiling DNA to form chromosomes, allow for the tight packing of DNA into the nucleus

Gene

A sequence of nucleotides that codes of a protein, and therefore a trait

Chromosome

A single strand of DNA coiled around proteins, visible during cell division

Autosome

All other chromosomes other than the sex chromosomes

Centromere

Area where the chromatids of a chromosome are attached

Homologous Chromosomes

Chromosomes that are the same length, centromere position, and carry genes for the same traits

Sex Chromosome

Chromosomes that participate in sex determination, contain other genes as well

XX

Female sex chromosomes

Locus

Location of a gene on a chromosome

q arm

Long arm of a chromosome

XY

Male sex chromosomes

Telomere

Repeating nucleotide sequences at the ends of chromosomes, protect the end of the chromosome from deterioration or from fusing with other chromosomes

p arm

Short arm of a chromosome, "petit"

Sister Chromatid

Structure that contains identical DNA copies and is formed during DNA replication

23

Total number of chromosomes in a gamete (reproductive cell - egg or sperm)

46

Total number of chromosomes in a normal, human body cell

Chromatin

Unraveled and not condensed form of DNA in a non-dividing cell, consists of DNA and protein