CAMPBELL BIOLOGY CHAPTER 12 EXAM QUESTIONS AND ANSWERS

CAMPBELL BIOLOGY CHAPTER 12 EXAM QUESTIONS AND ANSWERS cell division - answer- the process in reproduction and growth by which a cell divides to form daughter cells cell cycle - answer- series of events in which a cell grows, prepares for division, and divides to form two daughter cells genome - answer- all the DNA in one cell of an organism chromosome - answer- a threadlike body in the cell nucleus that carries the genes in a linear order chromatin - answer- the substance that composes eukaryotic chromosomes; it consists of specific proteins, DNA, and small amounts of RNA somatic cell - answer- cell that makes up all of the body tissues and organs, except gametes gametes - answer- reproductive cells, sperm cells and egg cells sister chromatids - answer- Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II. centromere - answer- a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape mitosis - answer- part of eukaryotic cell division during which the cell nucleus divides cytokinesis - answer- division of the cytoplasm during cell division Walther Flemming - answer- German scientist who in 1882 developed dyes that allowed him to observe the behavior of chromosomes during mitosis and cytokinesis, M phase - answer- the phase in the cell cycle where mitosis and cytokinesis occur resulting in cell division, the shortest part of cell cycle interphase - answer- the period of the cell cycle during which activities such as cell growth and protein synthesis occur without visible signs of cell division - about 90% of cell cycle G1 phase - answer- The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins. S phase - answer- The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated. G2 phase - answer- stage of interphase in which cell duplicates its cytosol and organelles prophase - answer- first and longest phase of mitosis in which the genetic material inside the nucleus condenses and the chromosomes become visible prometaphase - answer- The second stage of mitosis, in which discrete chromosomes consisting of identical sister chromatids appear, the nuclear envelope fragments, and the spindle microtubules attach to the kinetochores of the chromosomes. metaphase - answer- the stage in mitosis or meiosis in which the duplicated chromosomes line up along the equatorial plate of the spindle anaphase - answer- phase of mitosis in which the chromosomes separate and move to opposite ends of the cell telophase - answer- last phase of mitosis, chromosome are in two new cells and nuclear membranes start to reform mitotic spindle - answer- An assemblage of microtubules and associated proteins that is involved in the movements of chromosomes during mitosis. centrosome - answer- Central microtubule organizing center of cells. In animal cells, it contains two centrioles, which are not essential for cell division. aster - answer- A radial array of short microtubules that extends from each centrosome toward the plasma membrane in an animal cell undergoing mitosis. kinetochore - answer- a structure of proteins associated with specific sections of chromosomal DNA at each centromere metaphase plate - answer- An imaginary plane during metaphase in which the centromeres of all the duplicated chromosomes are located midway between the two poles separase - answer- -This is the enzyme that breaks down cohesion so that the chromatids can separate. cleavage - answer- the process of cytokinesis in animal cells, characterized by pinching of the plasma membrane cleavage furrow - answer- The first sign of cleavage in an animal cell; a shallow groove in the cell surface near the old metaphase plate. cell plate - answer- the precursor of a new plant cell wall that forms during cell division and divides a cell into two binary fission - answer- the division of a prokaryotic cell into two offspring cells