Exam # 3 Study Guide Lectures: 14 – 20Chapters 12 – 16Exam FormatThe exam will have matching sections mainly for any vocabulary, terms to know, types of proteins, and diseases. Be able to draw: a cell undergoing metaphase in mitosis, meiosis I, and meiosis II; a replicated chromosome; the complementary strands of a given strand of DNA; a pie chart showing the stages of the cell cycle; Punnett squares; and what cells like undergoing all of the stages of the cell cycle in both mitosis and meiosis. Fill in the blank questions will be asked mainly regarding vocabulary, sources of genetic variation, and genetic disorders. There will be a number of short answer/discussion questions that have been included in thestudy guide. Assume everything else is multiple choice. The answers to all of the assigned homework and quizzes regarding Exam 3 have been posted on Blackboard; assume they will also be on the exam.Chapter 12 (Lecture 14): The Cell CycleVocabulary to know:Genome – the complete set of genes in an organism contained in a single haploid set of chromosomesChromatin – the set of acids/proteins that condenses to form chromosomes that is found in either the nucleoid or nucleus; it packages DNA into smaller volumes to fit in the cell, strengthens the DNA to allow mitosis and meiosis, and controls gene expression.Nuclear Envelope – the membrane made up of a lipid bilayer that surrounds the nucleus that regulates the exchange of materials between the nucleus and cytoplasm; the outer membrane is the endoplasmic reticulum and the inner membrane is a network of intermediate filaments called nuclear lamina, which acts as a site of attachment for chromosomes. BIOL 101 1st EditionCentromere – the region where chromatids are held and kinetochore is formed; serves as the point of attachment for spindle fibers when the spindle fibers are pulling the chromosomes toward the centrioles - situated on opposite poles in a cell - prior to cytokinesis.Kinetochore –the region of each chromosome where the chromatids are held together to form an X shapeSpindle – a collection of fibers made of microtubules that forms during meiosisReplicated Chromosome – the second/new set of chromosomes that are formed after metaphaseSister Chromatid – two identical strands joined by a common centromere from a chromosome that duplicated during the S phase.Metaphase Plate – The plane of the spindle where the chromosomes are lined up during mitosis or meiosisThings to know:1. Describe the cell cycle “Interphase”.Interphase has 3 parts. During G1, the cell grows and gets bigger. During S, the DNA is replicated while the cell is still growing. During G2, the cell is getting ready for mitosis and cytokinesis by making the special proteins necessary for that to happen.2. Describe the cell cycle “Mitosis”. Mitosis is the division of the nucleus. It occurs in 5 stages. In prophase, the chromosomes are replicated, the nucleoli break down, and the spindle apparatus is formed, which will move the chromosomes around. Prometaphase involves the breakdown of the nuclear envelope, while the spindle apparatus attaches to replicated chromosomes at the kinetochore (protein complexes are located at the centromere where the sister chromatids are connected). During metaphase, these replicated chromosomes line up in the middle of the cell in a single-file fashion, and during anaphase, the sister chromatids separate, and are pulled to opposite poles of the cell. These new chromosomes decondense during Telophase, and the spindle apparatus disappears while the nuclear envelope reforms. 3. Which is the shortest, Interphase or Mitosis? Interphase is longer than mitosis because it is the process in which the cell is growing to perform mitosis again.4. What happens in each phase of the cell cycle?In prophase, the chromosomes are replicated, the nucleoli break down, and the spindle apparatus is formed, which will move the chromosomes around. Prometaphase involves the breakdown of the nuclear envelope, while the spindle apparatus attaches to replicated chromosomes at the kinetochore (protein complexes are located at the centromere where the sister chromatids are connected). During metaphase, these replicated chromosomes line up in the middle of the cell in a single-file fashion, and during anaphase, the sister chromatids separate, and are pulled to opposite poles of the cell. These new chromosomes decondense during Telophase, and the spindle apparatus disappears while the nuclear envelope reforms. Based on the type of cell, it will then enter cytokinesis, which is the point in which the cells are pinched and separated into 2 separate daughter cells. 5. What is cytokinesis? Cytokinesis is the division of the cytoplasm. It is the last stage of the cell cycle, and it differs in plant cell cells and animal cells. In animal cells, the cells are pinched apart, forming a “cleavage furrow” between the 2 newly formed nuclei. The microfilaments then form a ring at the cleavage furrow and tighten to pinchthe two cells apart. In plants, the vesicles from the Golgi meet and fuse in the center of the cell, which forms 2 new membranes within a single cell wall. These 2 new membranes then form individual new cell walls. 6. How is the cell cycle controlled? What is G0? What happens at the G1/S checkpoint?The cell cycle is controlled at checkpoints that give “start” and “stop” signals. The G1/S checkpoint determines if the cell will divide based on signals from the environment and internal signals. If it decides not to divide, it exits the cell cycle into what is called the G0, which is the non-dividing stage. Most cells in the body are in the G0 phase. 7. Draw a pie chart showing the stages of the cell cycle and the order in which they occur, as well as the location of checkpoints. Show the point in the cycle where the cell exits the cell cycle to enter the non-dividing state (G0).The chart starts at G1 phase and rotates clockwise. The point between the G2 phase and prophase is where the cell would exit the cycle and enter the non-dividing G0 state.8. Draw a cell in metaphase and label sister chromatids, kinetochore and spindle.9. How do cancer cells differ from normal cells with regard to cell cycle control?Cancer cells do not die; they are mortal. They also do not respond to cell cycle controls. When cancer cellsdo stop dividing, it is often at the wrong point in the cell cycle, and this results in some cancer cells