Lecture 10 Outline of Last Lecture I. Viruses and genetic material II. The lytic cycle III. The lysogenic cycle IV. Phage reproductive cycles V. Viruses and disease VI. Emerging viruses VII.AIDS: a “retrovirus” VIII.To c l o n e o r n o t t o c l o n e ? IX. Differentiation X. DNA packing XI. Animal Cloning XII.Cloning XIII.Stem cells have medical potential Outline of Current Lecture I. Like begets like, more or less II. Cells arise only from preexisting cells III. Binary Fission IV. THE EUKARYOTIC CELL CYCLE AND MITOSIS V. The cell cycle consists of two major phases VI. In the mitotic phase… BIOL 1543 Custom Edition These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best !used as a supplement to your own notes, not as a substitute. !VII.Interphase VIII.Prophase IX. Prometaphase X. Metaphase - Anaphase - Telophase & Cytokinesis XI. Cytokinesis XII.Review of the functions of mitosis: XIII.Anchorage, cell density, and chemical growth factors XIV.Apoptosis XV. Cancer XVI.THE GENETIC BASIS OF CANCER XVII.Carcinogen Current Lecture I. Like begets like, more or less a. In sexual reproduction, fertilization of sperm and egg produces offspring. b. In asexual reproduction, offspring are produced by a single parent, without the participation of sperm and egg. Their offspring are genetic copies of the parent and of each other.c. Other organisms reproduce sexually, creating a variety of offspring II. Cells arise only from preexisting cells a. Cell division is at the heart of the reproduction of cells and organisms because cells come only from preexisting cells. b. Prokaryotic cells reproduce asexually by cell division: binary fission. III. Binary Fission a. As the cell replicates its single chromosome, the copies move apart and the growing membrane then divides the cells i. in most prokaryotes and protists IV. THE EUKARYOTIC CELL CYCLE AND MITOSIS a. The large, complex chromosomes of eukaryotes duplicate with each cell division. i. A eukaryotic cell has many more genes than a prokaryotic cell and they are grouped into multiple chromosomes in the nucleus.b. Individual chromosomes contain a very long DNA molecule associated with proteins and are visible only when the cell is in the!process of dividing i.chromo= colored, some= body c.If a cell is not undergoing division, chromosomes occur in the form of thin, loosely packed chromatin fibers d.Before a cell starts dividing, the chromosomes replicate, producing sister chromatids joined together at the centromere. e.Cell division involves the separation of sister chromatids and results in two daughter cells, each containing a complete and identical set of chromosomes. V. The cell cycle consists of two major phases a. drawn in relative time spent in each section b. Know the phases and what happens in eachVI.In the mitotic phase… a. Cell division is a continuum of dynamic changes i. In mitosis, after the chromosomes coil up, a mitotic spindle moves them to the middle of the cell ii. The sister chromatids then separate and move to opposite poles of the cell, where two nuclei form iii. Cytokinesis, in which the cell divides in two, overlaps the end of mitosis b. Tw o p a r t s i. mitosis (the division of the genetic material ii. Cytokinesis the movement of the cytoplasm to the new cellsVII.Interphase a. three sections within i. G1 (growth 1) ii. DNA Synthesis (S) iii. G2 (growth 2) VIII.Prophase a. in mitosis b. early mitotic spindle - an array of micro-tubials and proteins that form between the opposite poles of the cell during mitosis c. Centrosome- the regulator IX. Prometaphase a. the centrosomes move to the poles of the cell X. Metaphase - Anaphase - Telophase & Cytokinesis a. Metaphase i. spindle fully formed ii. metaphase plate- the chromosomes have moved to the middle of the cell b. Anaphase i. the chromosomes split c. Telophase i. starts to reform d. Cytokinesis i. cytoplasm moves to the two cells XI. Cytokinesis a. Cytokinesis differs for plant and animal cellsi. In animals, cytokinesis occurs by a constriction of the cell (cleavage) 1. complete cleavage (separation) of the cells ii. In plants, a membranous cell plate splits the cell in two (do not totally separate/ incomplete cleavage) XII.Review of the functions of mitosis: a. Growth, cell replacement, and asexual reproduction i. When the cell cycle operates normally, mitotic cell division functions in 1. Growth (of the different tissue) 2. Replacement of damaged or lost cells (1and2 in both eukaryotes and prokaryotes) 3. Asexual reproduction (in prokaryotes and protists only)XIII.Anchorage, cell density, and chemical growth factors a. Most animal cells divide only when stimulated, and some not at all. i. In laboratory cultures, most normal cells divide only when attached to a surface (called anchorage dependence) ii. They continue dividing until they touch one another (called density-dependent inhibition) b. Growth factors are proteins (polypeptides) secreted by cells that stimulate other cells to divide (can lead to cancer) XIV.Apoptosis a. Programmed cell death b. Occurs billions of times daily c. “Cleaned up” by other cells (phagocytosis; phase=eat, cytosis=cell) i. phagocytosis is a specialized type of endocytosis Cells anchor to!dish surface!and divide.When cells have!formed a complete!single layer, they!stop dividing (density-!dependent inhibition).If some cells are!scraped away, the!remaining cells divide!to fill the dish with a!single layer and then!stop (density-dependent!inhibition).d. example being an unfertilized female egg XV.Cancer a. Growing out of control, cancer cells can produce malignant tumors i. Cancer cells divide excessively to form masses called tumors ii. Malignant tumors can invade other tissues iii. Radiation and chemotherapy are effective as cancer treatments because they interfere with cell division b. Tw o t y p e s i. malignant 1. severe and can metastasize (meaning they can move to a different location in the body) ii. benign 1. do not grow in an unlimited and aggressive manor, do not metastasize, do not invade other tissues c. Biopsyi. two types of testing 1. excisional a. remove the whole tumor mass b. not always done because the tumor may be too big or aggressive 2. incisional a. take just a piece of the tumor and test it ii. Three types of cancer treatment (can be one or all three depending on how bad it is) 1. radiation 2. chemotherapy 3. surgical