BIOL 2153 : Completed Notes For Test 2
Genetics 9/21/2012 5:35:00 PM
Cell Division and Chromosome Heredity
Cell Division
• Mitosis produces two identical daughter cells that are exact
replicas of the parental cell
• Most body cells are somatic cells (non-reproductive), usually with
chromosomes present in pairs, the number of chromosomes is the
diploid number (2n)
• The haploid chromosome number includes one of each
chromosome pair (n)
• Triploid (3n) cells have 3 copies of each chromosome
• Trisomic (2n+1) cells have one extra chromosome
Reproductive Cells
• Gametes are produced from germ-line, or reproductive cells
• Meiosis produces gametes that have half the number of
chromosomes as the original cell
• The gametes are not identical to one another
Chromosomes
• Sex chromosomes determine sex and differ between genders
• Discovery of genes on the sex chromosomes supported the
chromosome theory of heredity
Anatomy of a chromosome
• Chromosomes types are classified by the position of the centromere
SOME BASICS
OF
3.1 Mitosis Divides Somatic Cells
• Mitosis is the process of cell division that produces two genetically
identical daughter cells from one original parental cell
• It is precisely controlled to prevent either an excess or insufficient
number of cells
• Used for growth, to increase mass/size of an organism
• Used to replace worn out/old cells
Stages of the Cell Cycle
• Cell division is regulated by control of the cell cycle, a cycle of DNA
replication and division
• Cell cycles of all eukaryotes are similar
• The two principal phases of the cell cycle are M phase, the short
time during which the cells divide and a longer interphase (90%),
the time between M phases
Document Summary
Reproductive cells: gametes are produced from germ-line, or reproductive cells, meiosis produces gametes that have half the number of chromosomes as the original cell, the gametes are not identical to one another. Chromosomes: sex chromosomes determine sex and differ between genders, discovery of genes on the sex chromosomes supported the chromosome theory of heredity. Anatomy of a chromosome: chromosomes types are classified by the position of the centromere. Interphase: during the gap 1 (g1) phase of interphase, all proteins needed for normal cell function are transcribed and translated; the duration of. Substages of m phase: m phase is divided into, prophase, prometaphase, metaphase, anaphase, telophase, m phase accomplishes karyokinesis, partitioning of dna into daughter cell nuclei and cytokinesis, the partitioning of the cytoplasm. Mitosis produces identical daughter cells: mitosis separates replicated copies of sister chromatids into identical nuclei, forming two genetically identical daughter cells, the diploid number of chromosomes (2n) is maintained throughout the cell cycle.
