Slide 2 REVIEW QUESTIONS on your own paper- Use your notes- Turn
into pink basket. 1. How is a cancer cell affected by the cell
cycle? 2. Compare an internal regulator from an external regulator.
Include examples. 3. Which is worse, a benign tumor or a malignant
one and why? 4. Describe how a stem cell can become any other cell.
5. What are the two sources for stem cells and how are they Slide 3
Standards B-2.4 Explain the process of cell differentiation as the
basis for the hierarchical organization of organisms (including
cells, tissues, organs, and organ systems). B-2.6 Summarize the
characteristics of the cell cycle: interphase (called G1, S, G2);
the phases of mitosis (called prophase, metaphase, anaphase, and
telophase); and plant and animal cytokinesis. B-2.7 Summarize how
cell regulation controls and coordinates cell growth and division
and allows cells to respond to the environment, and recognize the
consequences of uncontrolled cell division. B-4.2 Summarize the
relationship among DNA, genes, and chromosomes. Slide 4 Vocabulary
Anaphase Beign Tumor Cancer Cells Cell Cycle Cell Plate Centromere
Checkpoint Chromatid Chromosome Cleavage Furrow Cytokinesis
Differentiation DNA External Signal Gap 1 Gap 2 Gene Internal
Signal Interphase Malignant Tumor Metaphase Mitosis Prophase Stem
Cells Synthesis Phase Telophase Slide 5 Book Sections 5-1 5-2 5-3
5-5 Slide 6 Slide 7 1. DNA, genes, and chromosomes compose the
molecular basis of heredity. a. A chromosome is a structure in the
nucleus of a cell consisting of one long thread of DNA that is
tightly coiled. DNA double helix DNA and histones Chromatin
Supercoiled DNA Slide 8 Slide 9 Slide 10 b. DNA is composed of
nucleotides and provides the blueprint for the synthesis of
proteins by the arrangement of the nitrogenous bases Slide 11 c. A
gene is a specific location on a chromosome, consisting of a
segment of DNA, that codes for a particular protein. i. The
particular proteins coded by the DNA on the genes determine the
characteristics of an organism ii. Each chromosome consists of
hundreds of genes determining the many proteins for an individual
organism. Slide 12 Slide 13 Slide 14 1. The cell cycle is a
repeated pattern of growth and division that occurs in eukaryotic
cells. 2. It consists of three main stages: Slide 15 a. Interphase
Cells spend most of their time in interphase. During this time the
DNA in the nucleus is loosely organized and looks like spaghetti.
i. G1 (gap 1) phase The cell carries out its normal functions
including growth and synthesizing proteins ii. S (synthesis) phase
Chromosomes copy themselves to form identical sister chromatids
that are held together by a centromere. iii. G2 (gap 2) phase Cells
continue to grow and produce proteins needed for cell division
Slide 16 Interphase Parent cell centrioles spindle fibers
centrosome nucleus with DNA Slide 17 Sister Chromatids Centromere
Slide 18 Slide 19 b. Mitosis Purpose is to divide the cell nucleus
and its contents. c. Cytokinesis Is the division of the cytoplasm
into two individual cells. Slide 20 * Cells that do not divide stay
in what is called G 0 Slide 21 Slide 22 1. Mitosis The DNA that was
replicated (sister chromatids) in Interphase has to be broken apart
during mitosis so that each new cell has only one double- stranded
chromosome. 2. Mitosis is divided into four phases: Slide 23 a.
Prophase i. Chromosomes condense and are more visible ii. The
nuclear membrane (envelope) disappears. iii. Centrioles (organelles
that make spindle fibers) travel to opposite poles of the cell. iv.
Spindle fibers form and begin to radiate toward the center of the
cell. Slide 24 Prophase Slide 25 b. Metaphase i. Spindle fibers
connect at the centromere of ii. The chromosomes are lined up
across of the middle of the cell. Slide 26 Metaphase Slide 27 c.
Anaphase i. The centromeres that join the sister chromatids split
ii. The sister chromatids are now individual chromosomes iii. The
spindle fibers shorten to pull the separated chromatids to opposite
poles of the cell. Slide 28 Anaphase Slide 29 d. Telophase i. The
chromosomes uncoil. ii. A nuclear envelope forms around the
chromosomes at each pole of the cell. iii. Spindle fibers break
down and dissolve. iv. Cytokinesis begins. Slide 30 Telophase Slide
31 3. Cytokinesis 2 types: a. Animal Cell Cytokinesis membrane
forms a cleavage furrow b. Plant Cell Cytokinesis A cell plate
forms halfway. A cell wall forms from the cell plate. Slide 32
Cytokinesis Slide 33 Slide 34 1. Cell Cycle Control a. The cell
cycle is driven by a chemical control system that triggers and
coordinates key events in the cell cycle. b. Internal Signals
involve sensing the presence of enzymes which are produced inside
the cell. Slide 35 c. External signals sensing of a chemical
outside of cell that tells it to grow i. Ex: Growth factors
proteins stimulate cell division. ii. Ex: Cell Cell Contact: When
cells meet and touch, they stop dividing. When cells are not
touching, mitosis occurs until they do Slide 36 d. Checkpoints are
critical control points where stop and go signals can regulate the
cycle. G1- DNA is checked for mistakes. If a mistake is present,
cell stops dividing G2 (beginning of G2) Rechecks replicated DNA
(after S) for mistakes M - checks to make sure all chromosomes are
lined up exactly in middle before anaphase G 0 Resting Cell stops
dividing Slide 37 2. Cancer Cells a. Cancer cells ignore the normal
signals to stop dividing. Uncontrolled cell division b. Starts when
one cell is transformed into a cancer cell. i. The immune system
will normally destroy this cell. ii. If it is not destroyed the
cell divides and each daughter cell will be a cancer cell. These
daughter cells continue to divide until a tumor forms. Slide 38
cancer cellbloodstreamnormal cell Slide 39 iii. Malignant Tumors 1.
When cancer cells invade and hurts the function of one or more
organs. 2. The cancer cells can break away from the tumor and be
carried through the bloodstream or lymph system to other parts of
the body where they form more tumors. iv. Benign Tumors 1. A mass
of abnormal cells that remains at the original site. Slide 40 Slide
41 Malignant tumors- cancer cells spread through blood vessels.
Slide 42 Slide 43 1. Homeostasis the maintenance of a stable
internal environment a. In multicellular organisms cells
communicate and work together to maintain homeostasis. b. A single
fertilized egg gives rise to many different types of cells that all
have different structures and functions. Slide 44 CELLTISSUEORGAN
Slide 45 Slide 46 Cell differentiation Slide 47 2. Cell
Differentiation a. Cell division by itself makes all identical
cells. b. Cell differentiation- takes unspecialized cells (stem
cells)and develops them into their mature forms and functions.
Slide 48 c. In a multicellular organism, all cells have the same
chromosomes and DNA. i. During differentiation, only specific parts
of the DNA are activated. The part activated determines the
function of the cell. ii. All cells have the potential to become
any type of cell. iii. Once a cell differentiates, it cannot be
reversed. Slide 49 3. Stem Cells a. Are unspecialized cells that
continually reproduce themselves and have the ability to
differentiate into one or more types of cells. b. There are two
types of stem cells: i. Embryonic Stem Cells 1. Embryonic cells
that have not differentiated yet. ii. Adult Stem Cells 1. Found in
adults such as in the bone marrow. Slide 50 Embryonic stem cells
Can become any type of cell Slide 51 Adult stem cells from bone
marrow Can only become a few types of cells. Slide 52 c. Scientists
have discovered that with the right laboratory conditions, both
embryonic and adult stem cells can be differentiated into
specialized cells. Slide 53 *Benefits of Stem Cells Stem cells are
used to treat leukemia and lymphoma. Stem cells may cure disease or
replace damaged organs. Stem cells may revolutionize the drug
development process.
