Chapter 4

 Standard #1: Cell Division (Mitosis) - 7.S  Standard #2: Cell Reproduction (Meiosis) - 7.S  Standard #3: DNA - 7.S  Standard #4: Models/Charts/Graphs/Data - 7.S.1.2.3/7.S.1.6.2/7.S.1.6.3

 Chromosome  Sexual reproduction  DNA  Mitosis  Asexual reproduction  Meiosis  RNA  Genes  Mutation  Cell Cycle  Interphase  Prophase  Anaphase  Metaphase  Telophase  Diploid  Haploid

The birth, life and death of cells.

 Cells have a life cycle  A cell life cycle is the birth, growth & development, death of a cell  Cell cycle consists of two major periods: interphase and cell division

 Interphase: a growth phase (long)  Interphase is divided into 3 phases:  G1 phase = growth phase (DNA & protein made)  S phase = DNA synthesis takes place (DNA replicates)  G2 phase = growth phase (RNA & protein made, proofreading DNA) cell cycle and mitosis

 Cell division: short phase  Cell division is divided into 2 phases:  1. Mitosis = nucleus of cell divides  2. Cytokinesis = cytoplasm divides  Cell division increases the number of cells in an organism  Cell division allows growth and replaces worn out or damaged cells

 Single celled organisms reproduce through cell division

mitosis only 1:30 min whole movie good cell cycle and mitosis min 1-4 animal cells cell cycle and mitosis

CHROMATIDS / CHROMOSOMES / GENES:

INTERPHASE:  DNA duplicates (goes from 46 chromosomes to 92 chromatids)  Growth phase  Interphase is NOT a step of Mitosis. It happens before mitosis begins.

 Cells division that results in 2 identical daughter cells

MITOSIS:  cell divides 1 time  Makes 2 identical copies  replace or makes new cells  Body cell go through mitosis  Diploid cells= cells with complete set of chromosomes PLb3m_5kPlQwOn78c2uHdyFbXn8RHPZAYK

 cell divides 1 time  Makes 2 identical copies  replace or makes new cells  Body cell go through mitosis  Diploid cells= cells with complete set of chromosomes

PROPHASE:  Cell gets idea that it is time to divide  DNA Condenses  Centrioles move to opposite ends of cell  Spindle fibers begin to form

PROPHASE:  Cell gets idea that it is time to divide  DNA Condenses  Centrioles move to opposite ends of cell  Spindle fibers begin to form

PROMETAPHASE:  Nuclear membrane breaks down  Spindle fibers attach to the chromosomes

METAPHASE: (MIDDLE)  DNA line up on center axis  Centromere of each pair attaches to spindle fibers

ANAPHASE: (AWAY)  Separation begins  Chromosomes splits and migrate to opposite sides  Anaphase complete when chromatids get the side of the cell

TELOPHASE: (TWO)  2 New nuclei form  Spindle fibers start to disappear  Chromosomes start to uncoil

CYTOKINESIS: (CYTOPLASM)  Not a step of mitosis.  It IS a step in the cell cycle.  Cytoplasm splits  Result = Two identical daughter cells formed.  Diploid cells = cells with complete sets of chromosomes.

REPRODUCTION:  Cell reproduction is process organism use to produce others of their own kind.

ASEXUAL REPRODUCTION:  Asexual reproduction: A way to make a new organism from one organism.  In asexual reproduction the heredity information is identical to the parent organism.

2 TYPES OF ASEXUAL REPRODUCTION:  Budding:  a new organism develops from an outgrowth (bud) on parent,due to cell division  Example: Paramecium& hydra & strawberries  Regeneration:  Process that uses cell division to regrow body parts.  Example: sponges  Another type of asexual reproduction is binary fission (bacteria, fungi, protest reproduce this way)

SEXUAL REPRODUCTION:  A way to make a new organism from gametes (sperm and egg) joining together.

 Recombination of genes

MEIOSIS:  Type of cell division  Produces 4 cells, with ½ the # of chromosomes as parent = Haploid cells  Happens when it is time to reproduce an organism  It shuffles the cell’s genes around  Cell divides 2 times (meiosis 1 & meiosis 2)

cell division that produces reproductive cells in sexually reproducing organisms. MEIOSIS DEFINITION:

MEIOSIS I :  Interphase I = DNA duplicated  Prophase I = nuclear membrane goes away  each duplicated chromosome comes near its similar duplicated mate  Metaphase I = pairs of duplicated chromosomes line up in center of cell.  Centromere of each chromatid pair becomes attached to one spindle fiber  Anaphase I = 2 pairs of chromatids pulled to ends of cell  Each duplicated chromosome still has 2 chromatids.  Telophase I = cytoplasm divides and 2 new cells form  Each new cell has 1 duplicated chromosome from each similar pair

MEIOSIS II:  2 cells from Meiosis I now start meiosis II  Prophase II = duplicated chromosomes & spindle fibers reappear in each new cell  Metaphase II = duplicated chromosomes line up at center of the cell  Centromere attaches to 2 spindle fibers instead of 1  Anaphase II = centromere divides, chromatids separate to opposite ends of cell  Telophase II = spindle fibers disappear & nuclear membrane forms  Cyctoplasm divides

RESULT OF MEIOSIS:  4 sex cells with 23 unpaired (unduplicated) chromosomes each

 1) DNA stands for Dioxyribonucleic acid.  2) DNA contains instructions that code for development, function and structure of an organism.  3) DNA carries genetic information that is passed form one generation to the next. 1 min 5 min good.

 1) DNA is a nucleic acid (organic compound) with subunits called nucleotides.  2) 3 Parts to nucleotides:  Phosphate group  Sugar (deoxyribose)  Nitrogen base – 4 different nitrogen bases:  Adenine (A)  Thymine (T)  Cytosine (C)  Guanine (G)  3) DNA is a double helix structure (twisted ladder)  Sides of ladder = alternate sugar phosphate group  Rungs of ladder = pairs of nitrogen bases

DNA REPLICATION:  1) In order for DNA to be passed from 1 generation to the next, it must be able to replicate an exact copy of itself.  2) DNA replicates before a cell divides.  3) Steps to DNA replication:  a. DNA helix unwinds  b. 2 strands unzips  c. Each strand acts as a template for the new strands.  d. Free nucleotides pair with bases along each of the DNA strands.  4) The result of DNA replication is 2 identical strands of DNA. 1 min

GENES:  1) Genes are a section of DNA on a chromosome.  2) Genes determine the order of amino acids in proteins.  3) Change the order of amino acids and you make a different protein.  4) Proteins are made of chains of amino acids.

RIBONUCLEIC ACID: (RNA)  1) RNA stands for ribonucleic acid.  2) RNA’s most important job is to synthesize protein.  3) RNA structure is a long, single stranded chain of nucleotides.  4) 3 Types of RNA:  a. mRNA: messenger RNA  b. rRNA: ribosomal RNA  c. tRNA: transfer RNA  5) RNA Structure:  Sides of ladder = Ribose sugar & phosphate  Rungs of ladder = 4 Nitrogen bases: Adenine, Guanine, Cytosine, Uracil

PROTEIN SYNTHESIS (MAKING PROTEIN):  1) Protein synthesis is the process of decoding DNA to make a protein.  2) Proteins are large molecules composed of subunits called amino acids.  3) In a protein, different amino acids are linked together in a specific sequence.  4) The sequence of nucleotides (A,T,G,C) in DNA determine the sequence of amino acids.

 1) Mutations are any permeant change in the DNA sequence of a gene or chromosomes.

Gene mutation or alterations in a genomic sequence can drastically impact a person's normal way of living. Such alterations can be either spontaneous or can be induced through radiation, viruses, mutagenic chemicals or transposons.chemicals Progeria Genetic Components: Alcoholism Color blindness Sickle cell Breast cancer Parkinson disease Autism