Biology - Meiosis Vocab Flashcards

Meiosis

the process in which gametes are created - produces cells with half the # of chromosomes as a normal cell - performed by all organisms that reproduce sexually

Gamete

a sex cell - sperm or egg

Chromatid

basically, a half of a chromosome (divide during anaphase in cell division)

Gene

the part of a chromosome that codes for a trait - (ex: a gene can code for flower color) - location on a chromosome

Sister Chromatids

exact copies of a chromosome that are linked by a centromere (same genes, same alleles)

Haploid (n)

cell that has a single set of unpaired chromosomes - results after meiosis

Diploid (2n)

cell that contains two complete sets of chromosomes (1 cell that has full # of chromosomes) - exists before meiosis starts

Crossing-over

happens during prophase 1 - when parts of two non-sister chromatids can break off and switch with each other - increases genetic variation

Oogenesis

process where female gametes are produced

Centromere

center of a chromosome - attaches two sister chromatids together

Tetrad

structure formed in prophase 1 - made of two homologous chromosomes & two sister chromatids

Gonad

testicles/ovaries - where meiosis occurs in an organism

Chromosomes

thread-like structures composed of DNA wound around protein within the nucleus - contain our genes & genetic code (makes all of us who we are)

Allele

a specific version of a gene - (ex: the version of the above gene that codes for red flower color) - information in the location on a chromosome (DON’T MISTAKE WITH A GENE - a gene is the general AREA)

Homologous Chromosome

a pair of chromosomes that code for the same traits, but are not identical (same genes, different alleles)

Spermatogenesis

process where male gametes are produced

Nondisjunction

when tetrads do not split where they should in meiosis 1 or sister chromatids do not split when they should in meiosis 2