Genetics - Chromosomes and Cellular Reproduction Terminology (Chapter 2)

prokaryote

unicellular organism with a simple cell structure; includes bacteria (eubacteria) and archaea

eukaryote

one of the three primary divisions of life, consisting of organisms whose cells have a complex structure including a nuclear envelope and membrane-bounded organelles; have unicellular and multicellular forms

nucleus

compartment in eukaryotic cells that is enclosed by the nuclear envelope and contains the chromosomes

histones

low-molecular-weight protein found in eukaryotes that complexes with DNA to form chromosomes

chromatin

material found in the eukaryotic nucleus; consists of DNA and proteins

homologous pair (homologs)

chromosomes that are the same in length, centromere position, and carry genes affecting the same traits; made of 2 DNA molecules

diploid

term for cells that carry 2 sets of chromosomes

haploid

term for cells carrying only a single set of chromosomes

polyploid

term for carrying more than two sets of chromosomes

centromere

the attachment point for spindle microtubules

telomere

tips of chromosomes

sister chromatids

genetically identical copies of a duplicated chromosome in the form of 2 DNA molecules

non-sister chromatids

duplicated chromosome in the form of 2 DNA molecules that are NOT genetically identical to one another

cell cycle

the series of stages through which a cell passes from one division to the next; includes interphase(G₁, S, G₂) and mitosis (m phase/PPMAT)

interphase

the period between cell divisions

G₁

first stage of interphase; growth occurs

S phase

second stage in interphase; DNA replication occurs

G₂

third stage in interphase; is the biochemical preparation for cell division

m (mitotic) phase

period of active cell division; includes mitosis (PPMAT), the process by which the nucleus of a eukaryotic cell divides

meiosis

the process by which the chromosomes of a eukaryotic cell divide to give rise to haploid reproductive cells

fertilization

when two haploid gametes fuse and restore the number of chromosomes to its original diploid value

spermatogenesis

the production of gametes in a male animal

oogenesis

the production of gametes in a female animal