BIOL 1406 Discussion Questions Meiosis and Sexual Life Cycles 1 Draw labeled diagrams showing the 10 stages of meiosis for a diploid cell where 2N 6 Use 3 different shapes to represent the different chromosomes in each set and use 2 different colors to represent the 2 sets of chromosomes Make sure you show the number shape color and location of the chromosomes at each stage of division Remember in some stages the chromosomes will be duplicated and in some stages they will not be duplicated Also include the spindle apparatus and nuclear membrane when appropriate 2 Diagram and describe the typical animal life cycle Be sure to indicate which stages are haploid and which are diploid Also indicate where mitosis occurs where meiosis occurs and where fertilization occurs 3 Diagram and describe the eukaryotic life cycle where a multicellular haploid generation alternates with a multicellular diploid generation alternation of generations Be sure to indicate which stages are haploid and which are diploid Also indicate where mitosis occurs where meiosis occurs and where fertilization occurs 4 Identify and describe at least 3 ways meiosis differs from mitosis 5 Describe the processes of independent assortment and crossing over and explain their biological significance 6 Describe the evolutionary significance of sexual reproduction 7 Six centromeres are observed in a prophase I cell from another species of insect a How many pairs of chromosomes does this organism contain b For each stage of meiosis indicate the number of centromeres you would expect to find and the number of copies of chromosomes attached to each centromere Stage of meiosis Anaphase I Prophase II Number of centromeres visible Number of chromosome copies attached to each centromere 8 Meiosis I is sometimes called a reduction division meiosis II is sometimes called an equational division Why 9 Meiosis results in a reassortment of maternal and paternal chromosomes If n 3 for a given organism there are 8 different combinations of paternal and maternal chromosomes If no crossing over occurs what is the probability that a gamete will receive only paternal chromosomes 10 Assume you are a microscopist viewing fruit fly cells that are undergoing mitosis Draw circles to represent the cell membrane for each stage of mitosis In each of the circles cell membranes draw what you would expect to see if you were looking at a cell in the stage of meiosis 11 TABLE Comparing Mitosis and Meiosis Interphase Mitosis Meiosis I Prophase Metaphase Anaphase Telophase cytokinesis Meiosis II 12 TABLE Mitosis vs Meiosis Interphase Prophase Metaphase Anaphase Telophase Mitosis Meiosis Similarities Mitosis Meiosis Differences 13 If the amount of DNA in a somatic cell equals 4 picograms during G1 of interphase then how much DNA is present in the cell during each phase of mitosis and meiosis Amount of DNA in Interphase Prophase Metaphase Anaphase Telophase Mitosis Meiosis I Meiosis II 14 How do the similarities in prophase of mitosis and meiosis compare with the similarities in telophase of mitosis and meiosis 15 At what stage s does do most of the differences among mitosis meiosis I and meiosis II occur Why do these differences exist 16 The DNA content of a diploid cell in the G1 phase of the cell cycle is measured If the DNA content is x then the DNA content of the same cell at metaphase of meiosis I would be 17 The DNA content of a diploid cell in the G1 phase of the cell cycle is measured If the DNA content is x then the DNA content at metaphase of meiosis II would be 18 Which of the following would not be considered a haploid cell a daughter cell after meiosis II b gamete c daughter cell after mitosis in gametophyte generation of a plant d cell in prophase I e cell in prophase II 19 A cell in G2 before meiosis compared with one of the four cells produced by that meiotic division has a twice as much DNA and twice as many chromosomes b four times as much DNA and twice as many chromosomes c four times as much DNA and four times as many chromosomes d half as much DNA but the same number of chromosomes e half as much DNA and half as many chromosomes 20 The following diagrams show a diploid cell with 2 chromosomes 1 and 2 The chromosome derived from the mother is denoted m and the chromosome derived from the father is denoted d a The picture below shows the end of mitosis meiosis I meosis II Circle one b The picture below shows the end of mitosis meiosis I meosis II Circle one c The picture below shows the end of mitosis meiosis I meosis II Circle one d In which stage of mitosis or meiosis does most of the recombination occur Explain why This material was created by or adapted from material created by MIT faculty members Professor Hazel Sive Professor Tyler Jacks Dr Claudette Gardel Introductory Biology 2004 Copyright Year Professor Hazel Sive Professor Tyler Jacks Dr Claudette Gardel