The Reproductive System: Part A - Next2Eden

Number ofdivisionsSynapsis ofhomologouschromosomesDaughter cellnumber andgeneticcompositionRoles in the bodyMITOSISOne, consisting of prophase, metaphase,anaphase, and telophase.Does not occur.Two. Each diploid (2n) cell is identical tothe mother cell.For development of multicellular adultfrom zygote. Produces cells for growthand tissue repair. Ensures constancy ofgenetic makeup of all body cells.MEIOSISTwo, each consisting of prophase, metaphase,anaphase, and telophase. DNA replication doesnot occur between the two nuclear divisions.Occurs during mitosis I; tetrads formed,allowing crossovers.Four. Each haploid (n) cell contains half as manychromosomes as the mother cell and isgenetically different from the mother cell.Produces cells for reproduction (gametes).Introduces genetic variability in the gametes andreduces chromosomal number by half so that whenfertilization occurs, the normal diploid chromosomalnumber is restored (in humans, 2n = 46).Copyright © 2010 Pearson Education, Inc. Figure 27.5 (2 of 2)