33 terms

Essential Biology: Chapter 8: Cell Reproduction

rod shaped structures made of DNA and protein
the DNA in eukaryotic cells wrapped around tightly around the proteins
a half of a chromosome, so there are two chromatids to each chromosome
the point where chromatids are attached
the less tightly wound DNA-protein complex where transcription and translation occurs
sex chromosome
chromosome that determines the sex of the organism , and may contain genes for other characteristics
all chromosomes other than sex chromosomes
homologous chromosomes
chromosomes that have the same size, shape, and genetic information
photomicrograph of trhe chromosomes in a normal dividing cell found in a human
cells that have two sets of chromosomes, each has two copies of each autosome and two sex chromosomes
sperm and egg cells, which only contain one set of chromosomes
binary fission
the division of a prokaryotic cell into two offspring cells
creates new cells with genetic material that is identical to the genetic material of the original cell
asexual reproduciton
production of offspring from one parent
reduces the chromosome number by half in the new cells to create gametes
haploid reproductive cells
the time between cell division, which is one phase of the cell cycle, but has three stages- G1, S, and G2
the division of a cell's cytoplasm
the first phase of mitosis and meiosis in cell cell division; characterized by the condensation of the chromosomes, the dissolution of the nuclear envelope, and formation of the spindle fibers
spindle fiber
made of microtubules and radiate from the centrosomes in preparation for metaphase
the second phase of mitosis and meiosis during which all of the chromosomes move to the cell's equator
the third phase of mitosis and meiosis in which the spidle fibers cause the chromosomes to separate
the final phase of mitosis and meiosis in which the nuclear membrane forms around each set of new chromosomes, the chromosomes decondense and the spindle fiber dissociate
cell plate
occurs only in plant cells- the vesicles from the Golgi apparatus join together at the midline of the dividing cell
the pairing of homologous chromosomes only in meiosis 1 (prophase 1), not in mitosis
the name for each pair of homologous chromosomes
crossing- over
the process of portions of chromatids breaking off and attaching to adjacent chromatids on the homologous chromosome
gentic recombination
the process of crossing-over that permits for the exchange of genetic materical between maternal and paternal chromosomes; results in a new mixture of genetic material
independent assortment
the random separation of the homologous chromosomes, resulting in genetic variation
the production of sperm cells
the production of mature egg cells, or ova
polar body
extra three products of meiosis that eventually degenerate
sexual reproduction
the production of offspring through meiosis and the union of a sperm and an egg cell