genetics part 2 vocab

• gene - segments of chromosomes that carry heritable information
• alleles - different variations/versions of the trait
• chromosomes - structure within the nucleus of a cell that contains specific genes
• egg - female sex cell
• gamete- any sex cell (egg or sperm)
• sperm - male sex cell
• fertilization - joining of sperm and egg
• zygote - a fertilized egg
• diploid - a cell that contains two sets of chromosome

  (di=2, ploid=refers to chromosomes)

  (diploids=2n, n=number of different chromosomes)
• haploid - having 1/2 the normals number of chromosomes - eggs and sperms are haploid cells
• meiosis - special kind of cell division that forms gametes (sex cells)

  • only occurs in reproductive cells in testes or ovaries
  • produces cells that have 1/2 as many chromosomes as normal body cells
• homologous - look the same

  • have genes for the same traits, but not necessarily the same variation/version of the genes
• sister chromatid - formed during interphase and is identical copy of the original chromosomes linked together by a centromere
• crossing-over - exchange of segments of a chromosomes between non-sister chromatids of homologous chromosomes which include genetic variation
• interphase - process that occurred before mitosis and meiosis that allows chromosomes to replicate (identical copy of the chromosome)
• mitosis - how body cells replicate

  • forms new cells for repair of damaged ones
  • allows zygote (single cell) to become a human