Exam 3 Study Guide Chapter 12 The Cell Cycle Mitosis and Cancer 1 Identify the stages in the eukaryotic cell cycle and describe their principal events a Interphase cell grows by producing proteins and cytoplasmic organelles such as mitochondria and endoplasmic reticulum i G1 first gap not really gap ii S synthesis duplication of the chromosomes crucial for eventual division of the cell iii G2 where spindle begins 2 Describe the structure of a duplicated chromosome including the sister chromatids centromeres and kinetochores a Sister chromatids has 2 of them joined copies of the original chromosome b Centromeres region of the chromosomal DNA where the chromatid is attached most closely to its sister chromatid c Kinetochores structure made up of proteins that have assembled on specific sections for DNA at each centromere 3 Describe how the mitotic spindle is organized including the functions of the kinetochore and non kinetochore microtubules a Mitotic spindle begins to form in the cytoplasm during prophase i Fibers made of microtubules and associated proteins Exam 3 Study Guide 4 Explain the significance of mitosis and describe the stages a G2 Interphase i Nuclear envelope encloses the nucleus ii Nucleus has a nucleolus iii A centrosome duplicates b Prophase 1 Centrosome organize microtubules of the spindle has centrioles iv Chromosomes cannot be seen individually i Chromatin becomes tightly coiled into discrete chromosomes ii Nucleoli disappears iii Duplicate chromosome appears as 2 identical sister chromatids joined at the centromeres iv Mitotic spindle begins to form 1 Centrosomes 2 Microtubules extending 3 Asters radial arrays of shorter microtubules v Centrosomes move away from each other partially due to the microtubules lengthening c Prometaphase i Nuclear envelope fragments ii Microtubules invade the nucleus area iii Chromosomes become even more condensed iv Sister chromatids have a kinetochore protein structure at the centromere v Microtubules attach to the kinetochores becomes kinetochore microtubules which jerk chromosomes back and forth vi Non kinetochore microtubules interact with those form the opposite side of the cell d Metaphase e Anaphase i Centrosomes are at the opposite poles ii Chromosomes at the metaphase plate equidistant between the two poles 1 Centromeres on the metaphase plate iii Kinetochores of the sister chromatids are attached to kinetochore microtubules coming from opposite poles i Shortest stage of mitosis ii Cohesion proteins cleave which let the sister chromatids to part this is when the chromatids are considered chromosomes iii The chromosomes begin moving toward opposite ends of the cell as their kinetochore microtubules shorten 1 Motor protein breaks down the subunits of microtubule in order to shorten it iv Nonkinetochore microtubules lengthen to elongate the cell Exam 3 Study Guide f Telophase i Daughter nuclei form in the cell ii Nuclear envelopes arise from fragments as well as other parts of the endomembrane system iii Nucleoli reappear iv Chromosomes became less condensed v Remaining spindle microtubules are depolymerized i Formation of cleavage furrow pinches the cell in two 5 Describe the ways in which the cycle is controlled by the cell cycle control g Cytokinesis genes Cdk and cyclin a Cyclin protein that gets its name from its cyclically fluctuating b Cyclin dependent kinases activity rises and falls with changes in the concentration in the cell concentration of the cell c MPF maturation promoting factor d Cyclin level rises through S and G2 and falls abruptly during M mitosis due to MPF e Growth factors protein released by certain cells that stimulates other cells to divide i i i i i i i i i i i i i i Density dependent inhibition crowded cells stop dividing ii Anchorage dependence in order to divide cells must be attached to a substratum inside of a culture flask or the extracellular matrix of a tissue 6 Describe how a normal cell can be transformed into a cancer cell What is metastasis and what is angiogenesis Exam 3 Study Guide a Normal cell can transform through a mutation b They do not need growth factors in their culture medium to grow and divide i Make their own growth factor ii Initiate growth factor signaling with the presence of the growth factor iii Abnormal cell cycle control system c Ex Henrietta Lacks cancerous tumor removed from her and her cells d Metastasis spread of cancer cells to locations distant from their began to divide nonstop original site e Angiogenesis when a cancer cell stimulates new blood vessel formation in order to invade lymphatic and blood vessels i Occurs in malignant tumors cells can escape the space they were in and enter into the bloodstream through the new blood vessel it created 7 Compare and contrast oncogenes and tumor suppressors and give an example of each control cell division a Oncogenes cancer causing genes switched on by growth factors and i Abnormal become permanently on and accelerate the cell cycle and cause cancer ii Types of cancer cervical bladder liver iii G Protein Ras oncogene mutations cause more than 30 of all cancers b Tumor suppressor genes code for proteins that normal block cell division when errors in mitosis are found i Loss of tumor suppressors due to mutation deletion or inactivation can cause cancer by eliminating the brakes of the cell cycle ii Types of cancer breast cancer p53 and BRAC1 iii p53 mutations cause more than 50 of all cancers 8 Explain the 4 unusual features of cancer cells Explain three general categories of drug therapy or cancer a Immortal they divide indefinitely if supplied with the necessary nutrients b Unusual karyotype the chromosome number can be different as well as the cell could have mutations to it c Abnormal cell surface round up and break attachments from d neighboring cells which allows metastasis Ignore density dependent inhibition of growth they multiply after contact with other cells and pile up until all the nutrients are exhausted Chapter 13 Meiosis and Sexual Life Cycles Exam 3 Study Guide 1 Distinguish between haploid and diploid cells and define homologous chromosomes a Haploid cells cell that contains a single set of chromosomes n 23 b Diploid cells cell that contains 2 chromosome sets 2n 46 c Homologous chromosomes 2 chromosomes of a pair that have the same length centromere position and staining pattern carry genes controlling the same inherited characters 2 Distinguish the key events in meiosis that result in reduction