Straighterline Intro to Biology 101 Chapter 5 Latest Update Graded A+

Straighterline Intro to Biology 101 Chapter 5 Latest Update Graded A+ Somatic cells Body cells Apoptosis programmed cell death Cell cycle orderly set of stages that take place between the time a cell divides and the time the resulting cells also divide Chromatid One DNA molecule Sister Chromatids identical DNA sequences Mitosis division of nucleus and genetic material Cytokinesis division of cytoplasm Caspases enzymes that bring about apoptosis Proto-oncogenes encodes proteins that promote cell cycle and prevent apoptosis Oncogenes Cancer causing gene formed by a mutation in a proto-oncogene, codes for a protein that overstimulates the cell cycle Chromatin Network of DNA strands and associated proteins observed within a nucleus of a cell. Diploid (2n) two of each type of chromosome is present Haploid (n) one of each type of chromosome is present Centromere constriction where sister chromatids of a chromosome are held together Daughter Chromosome structures produced by the separation of the sister chromatids Spindle Collection of microtubules that assist in the orderly distribution of chromosomes during cell division Prophase First phase of mitosis; characterized by the condensation of the chromatin; chromosomes are visible, but scattered in the nucleus Prometaphase Second phase of mitosis; characterized by the attachment of spindle fibers to kinetochores of each sister chromatid Metaphase Third phase of mitosis; chromosomes are aligned at the metaphase plate Anaphase Fourth phase of mitosis; chromosomes move toward the poles of the spindle Telophase Final phase of mitosis; daughter cells are located at each pole Cytokinesis cytoplasmic cleavage Cleavage furrow an indentation of the membrane between the two daughter nuclei Homologous chromosome Member of a pair of chromosomes that are alike and come together in synapsis during prophase of the first meiotic division; a homologue Synapsis Pairing of homologous chromosomes during meiosis I Gametes sex cells - sperm and egg Fertilization Fusion of sperm and egg nuclei, producing a zygote that develops into a new individual Crossing-over Exchange of segments between nonsister chromatids of a bivalent during meiosis Independent Assortment Alleles of unlinked genes segregate independently of each other during meiosis so that the gametes can contain all possible combinations of alleles Interkinesis period of time between Meiosis I and Meiosis II Spermatogenesis Production of sperm in males by the process of meiosis and maturation Oogenesis Production of eggs in females by the process