Chapter 8 Vocabulary

Autosome

Centromere

Chromatid

-- All of an organisms chromosomes, except -- The for the area of the chromosome where the--two One sister copy and one original chromosome held two sex chromosomes chromatids are held together together by a centromere -- Determine the traits of an organism that -- are Links not two chromatids together sex-linked or gender related -- a.k.a. Protein Disk

Haploid

Histone

-- Attached to spindle fibers during mitosis

Homologous Chromosome

-- Human sperm and egg cells

-- A protein molecule that DNA wraps around -- One during pair (two copies) of each autosome chromosome formation -- Have only one chromosome of each homologous -- Same size and shape pair -- Helps maintain the shape of a chromosome -- Carry genes for the same traits -- Half the number of a diploid cell -- Aid in tight-packing DNA -- May differ in views on trait(s)

Sex Chromosome

Cell Cycle

Centriole

-- A chromosome that determines the sex--ofThe an repeating set of events that make up -- In the animal life cells, a small pair of cylindrical bodie organism and sex-linked traits of a cell in each centrosome -- Normal Human Male: XY

-- Growth, Synthesis, Preparation, Cell Division -- Only appear during mitosis

-- Normal Human Female: XX

-- I M C

Cytokinesis

G0 Phase

G1 Phase

-- The process of the division of the cytoplasm -- Cells in do not copy DNA or prepare for division -- First period of a cell's life (I) order to form two new cells -- Last step of cell cycle -- Fully developed cells in the central nervous -- Cell growth (cell doubles in size) -- Animal Cells: cell membrane pinches inward system don't divide

-- Plant Cells: cell plate forms on mid-line eventually -- Gap following cell division and preceding DNA divides -- The human body has many cells in this phase replication

Meiosis

Mitosis

S Phase

-- The process of nuclear division that reduces -- Eukaryotic the nuclear division -- Second period of interphase during which number of chromosomes in a cell by half replication of DNA occurs -- Prophase, Metaphase, Anaphase, Telophase -- Nucleus breaks down, chromatids line up on mitotic spindles, they break away, two new nuclei form, and spindle / centrioles break down

Asexual Reproduction

Crossing-over

Gamete

-- Production of offspring from one parent-- Exchange of genes by reciprocal segments -- Result of of meiosis in humans homologous chromosomes during meiosis -- Does not involve meiosis or union of gametes -- Reproductive cells (haploids) -- Permits exhange of genetic material between -- Offspring genetically identical to its parent maternal and paternal chromosomes -- Human: sperm and egg -- Results in genetic recombination

Sexual Reproduction

Spermatogenesis

Synapsis

-- Production of offspring through meiosis --and Thethe production of sperm cells -- Pairing of homologous chromosomes during union of a sperm and an egg Prophase I (Meiosis I) -- Development: -- Genetically different from parents 1. Diploid reproductive cell divides -- Does not occur during mitosis meiotically into four haploid cells -- Enables adaptation to new conditions 2. Cells mature into sperm cells

Diploid -- A cell that contains both chromosomes of a pair of homologous chromosomes -- All human cells, except for reproductive cells -- Includes sex chromosomes

Karyotype -- A photomicrograph of the chromosomes in a dividing cell in a normal human -- 46 Chromosomes in a Human -- 22 Pairs of Autosomes / 1 Pair of Sex

Centrosome -- A dark body containing a centriole in animal cells but not in plant cells -- Spindle fibers radiate from it in G2

G2 Phase -- Final period of Interphase -- Rapid growth and preparation for mitosis

-- Represents time gap following DNA synthesis and preceding cell division

Spindle Fibers -- Made of microtubules -- Radiate from centrioles in preparation for mitosis -- Form mitotic spindle -- Equally divide chromatids between offspring

Oogenesis -- The production of mature egg cells, ova -- Diploid reproductive cell divides meiotically to produce one mature egg cell (ovum)

Tetrad -- A pair of homologous chromosomes -- Chromatids of homologous chromosomes are aligned length wise, so that genes of one are adjacent to corresponding genes on the other