Chromosome Structure and Function
number of sex chromosomes in human somatic cells
2 or 1 pair; female: XX; male: XY
human chromosome number
2N=46
number of autosomes in human somatic cells
44 or 22 pairs
sex chromosomes
Chromosomes that determine the sex of an individual
histones
Protein molecule around which DNA is tightly coiled in chromatin
fertilization
The union of haploid (N) gametes to produce a diploid (2N) zygote.
somatic cells
all body cells except the reproductive cells
haploid
an organism or cell having only one complete set of chromosomes and is a mixture of the chromosomes of parents (N=23)
centromere
area where the chromatids of a chromosome are attached
chromatin
chromosomes in a cell that is not actively dividing/reproducing; less tightly coiled
autosomes
chromosomes other than sex chromosomes
nucleus
control center of the cell
homologous chromosomes; homologues
each of the 23 pairs of human chromosomes consists of 2 homologues w/ similar size, shape, and genetic content; each homologue is inherited from 1 of 2 parents.
zygote
fertilized egg (2N)
karyotype
photograph of chromosomes grouped in order in pairs
sex cells
specialized cells that are used in reproduction;egg and sperm; gametes
2N
symbol for diploid
N
symbol for haploid
diploid
term used to refer to a cell that contains both sets of homologous chromosomes, one set from each biological parent (2N=46)
chromosomes
threadlike structures made of DNA molecules that contain the genes (hereditary material)
chromatids
two exact copies of DNA that make up each chromosome