BIOL 203 Lecture Notes - Lecture 12: Synaptonemal Complex, Sister Chromatids, Metaphase
Document Summary
Living organisms distinguished by their ability to reproduce and create variation. Heredity: the transmission of traits from one generation to the next. Variation: demonstrated by the differences in appearance between offspring, parents, and siblings. Genes: the units of hereditary, made up of segments of dna, passed from generation to generation through gametes, each gene has a speci c locus on a certain chromosome. A single passes genes to its offspring. Each have a unique combination of genes inherited from parents. Chromosomes: somatic cells diploid (2n) Have 23 pairs of chromosomes 46 chromosomes total: karyotype: ordered display of pairs of chromosomes. Pairs of chromosomes are called homologous chromosomes: homologous chromosomes: paired chromosomes (homologs) Same length & shape & centromere location. Carry genes the control the same inherited characters. Autosomes: all pairs of chromosomes except sex chromosomes. Sex chromosomes: xx or xy one pair of homologous chromosomes, x carries genes that y doesn"t & vice versa.
