Mitosis vs Meiosis. Mitosis and Meiosis -- Internet Tutorial

Transcription

1 Mitosis and Meiosis -- Internet Tutorial In this internet lesson, you will review the steps of mitosis and meiosis and view video simulations of cell division. Mitosis: An Interactive Animation ( On the left side of the screen is a navigation bar, click on the link to MITOSIS Read the text on this page and view the animation, you can slow down the video by clicking step by step through the phases. There is text about the animations below the animation that you can read to help you. 1. List the stages of mitosis. Include small pictures of each stage. 2. In which stage does the following occur Chromatin condenses into chromosomes Chromosomes align in center of cell. Longest part of the cell cycle. Nuclear envelope breaks down. Cell is cleaved into two new daughter cells.

2 Daughter chromosomes arrive at the poles. Watch the cells alive animation carefully (you can pause and click on each phase individually). 3. The colored chromosomes represent chromatids. There are two of each color because one is an exact duplicate of the other. --How many chromosomes are visible at the beginning of mitosis? -- How many are in each daughter cell at the end of mitosis? The little green T shaped things in the top of the cell are centrioles. -- What happens to the centrioles during mitosis (watch them and notice what happens in each stage)? GAP 1 of cell cycle-review protein synthesis: In the middle of the page, click on Transcribe and Translate a Gene Follow the bolded directions on the page to transcribe and translate the gene. Answer the following questions before or after you do the web simulation. You may need to reference your notes to answer some of them. 1. Review: Define transcription. 2. Where in the cell does transcription happen? 3. What is the enzyme that facilitates transcription? 4. What is made during transcription? 5. Define translation.

3 6. Where in the cell does translation happen? 7. What are the two types of nucleic acids that facilitate translation? 8. What is made during translation? At the top horizontal arrows click on molecular inheritance and go to central dogma Click on WHAT MAKES A FIREFLY GLOW Click PLAY and answer the following questions as you go: Fireflies glow to attract a and to avoid. RNA polymerase binds to the gene. When transcription is complete, the LUC mrna moves to the. The ribosome interprets the mrna to produce a string of. In order to become a functioning luciferase enzyme, the string must. The enzymes bind to to create light. Meiosis introduction tutorial: See the Contents: You will browse through each topic. Part 1: Reproduction 1. Give an example of asexual reproduction.

4 2. What is a clone? 3. Name the two types of gametes produced by meiosis: Part 2: Chromosomes in a Diploid Cell 4. What is the diploid chromosome number for humans? 5. Egg and sperm cells are [ haploid / diploid ] Part 3: Meiosis 1 and Meiosis 2 6. Name the stage of meiosis 1 where each of the following occurs: Homologous chromosomes pair and form synapses Bivalents align at metaphase plate Two complete daughter cells form

5 Nuclear membrane disappears. Nuclear membrane reforms. Chromosomes move to separate poles. View the meiosis 1 and 2 animation 12. At the end of meiosis 2, each cell contains how many chromosomes? Part 4: A Review of Meiosis 13. Name 2 errors that can occur during meiosis. Go to McGraw Hill: and watch the animation about meiosis I. 1. Explain the part of prophase 1 where crossing of chromosomes occurs and draw a diagram of the process: 2. Answer the quiz questions from the animation: Which of the following events occur during prophase I? A) breakdown of nuclear envelope B) condensation of chromosomes C) movement of centrosomes D) A and B E) A, B and C

6 2. How many bivalents are formed in a cell with 20 chromosomes at the beginning of meiosis I? A) 1 B) 5 C) 10 D) 20 E) Which of the following events occur during anaphase I? A) separation of homologous chromosomes B) formation of synaptonemal complex C) lengthening of kinetochore microtubules D) A and B E) A, B and C 4. At the end of meiosis I, there are two haploid cells, each with two sister chromatids per chromosome. A) True B) False 5. The period between meiosis I and II is termed interkinesis. A) True B) False

7 REVIEW DNA-RNA-protein---Go to my website dvusd.org/mrhs-oshea and download the word version of this portion of the activity. Use CHAPTER 8 of text for reference and/or the internet information associated with this activity: Below are some picture boxes and text boxes diagraming the process of protein synthesis. Put the pictures in order and then put the text boxes below the appropriate picture. Use these words to label the pictures DNA, mrna, Nuclear pore, RNA Polymerase, trna, amino acid, codon, anticodon. Then to Coleen.OShea@dvusd.org RNA Polymerase unwinds DNA. trna anticodons carrying amino acids pair up with the matching mrna codons Ribosome bonds amino acids together to form a protein. Ribosome attaches to the mrna strand RNA Polymerase adds complementary bases to form mrna mrna leaves the nucleus A parent strand of DNA serves as a template in the nucleus

8 How gametes are made: Watch this video on spermatogenesis spermatogenesis quiz_1_.html (making sperm): Draw the stages (including chromosome number at each stage) starting with the spermatogonium spermatocyte 2ndary spermatocytes spermatids sperm cells Check out this diagram of oogenesis (making eggs): Draw the stages (include chromosome # s): Now take the quiz: Problem 1: Number of chromosomes A human cell has 46 total or 23 pairs of chromosomes. Following mitosis, the daughter cells would each have a total of chromosomes. After meiosis I, the two daughter cells would have chromosomes, and after meiosis II chromosomes. A. 46, 46, 46 B. 46, 23, 23 C. 23, 23, 23 D. 46, 12, 12 Problem 2: Four different cells The process of meiosis produces four cells with nonidentical chromosomes. This diversification occurs during: A. telophase I

9 B. prophase I C. metaphase II D. prophase II Problem 3: Mitosis vs. Meiosis Which of the following is unique to mitosis and not a part of meiosis? A. homologous chromosomes pair forming bivalents B. homologous chromosomes cross over C. chromatids are separated during anaphase D. homologous chromosomes behave independently Problem 4: Thompson Seedless Grapes The Thompson seedless grape is triploid, with three copies of each chromosome. Which phase of the cell cycle would you expect triploid cells to be unable to complete. A. meiosis I B. S C. meiosis II D. G2 Problem 5: Asexual vs. sexual reproduction Some organisms are capable of asexual or sexual reproduction. Under favorable conditions, reproduction proceeds asexually. When conditions become more stressful reproduction switches to a sexual mode. Why? A. Sexual reproduction is simple and more rapid allowing larger numbers of offspring to be produced. B. Sexual reproduction requires two separate individuals, who can mutually provide nutrient support during stress. C. Asexual reproduction requires more energy.

10 D. Sexual reproduction produces individuals with new combinations of recombined chromosomes increasing diversity. Problem 6: Haploid cells The stage of meiosis where cells become haploid. A. prophase I B. prophase II C. anaphase I D. anaphase II Problem 7: Events of meiosis One of the earliest events that distinguishes meiosis occurs in prophase I and involves: A. Condensation of chromosomes B. Loss of the nuclear membrane C. Movement of chromosomes towards the metaphase plate D. Pairing of homologous chromosomes Problem 8: Ocean coral Coral in the ocean grows by budding, where the new organism grows out of the old one by mitosis. This form of replication is an example of: A. meiosis to produce a zygote B. asexual reproduction C. sexual reproduction D. gamete formation Problem 9: Phases of meiosis most closely resembles events of mitosis except that the cells are.

11 A. interphase, diploid B. meiosis II, diploid C. interphase, haploid D. meiosis II, haploid Problem 10: Anaphase During anaphase, a free kinetochore formed by disrupting an attached spindle fiber results in an immediate block to the process. This result shows that: A. The chromosomes themselves provide the energy for anaphase through their attachment to spindle fibers. B. The cells have mechanisms to insure that errors are not made during anaphase.