Cell Cycle Webquest

Name: ________________________ Per. _1__________ 10/2 Date: __ _8_/2_0_2_0______________ CELL CYCLE WEBQUEST Part A. MITOSIS Practice Interphase Prophase Metaphase Anaphase Telophase Cytokenesis 10. 11. 12. 13. 14. 15. 46 ______ In humans, each cell (except sex cells) has how many chromosomes? __ After mitosis, how many daughter cells are produced? _2 ______ 30 ______ After mitosis (in a human cell), each daughter cell has how many chromosomes? __ How many phases are in MITOSIS? _5 _____________ Which phase of the cell cycle is the longest? _Int_er _p_h_as_e____________ na_ph as_e___________ During which phase does cytokinesis begin? _A_ __ Part B. “Test Yourself”  Click on “Problem 1”  Answer each of the next 11 questions. 11 _________ / 11 How did you do?__ Part C. Read instructions on each page and press “Next” to continue each time. Interphase Prophase Metaphase Anaphase Telophase Total number of cells 21 10 1 2 2 36 percent of cells 55.6 27.8 8.3 5.6 3 100% Analysis Questions: 1. Explain how mitosis leads to two daughter cells, each of which is diploid (two full sets of chromosomes) and genetically identical to the original. The cell copies its chromosomes and then splits the copied chromosomes equally to make sure that each daughter cell has a full set. 2. What activities are going on in the cell during interphase? During interphase, the cell copies its DNA in preparation for mitosis. 3. How does mitosis differ in plant and animal cells? How does plant cell mitosis accommodate a rigid, inflexible cell wall? In plants, a new cell plate is formed between the daughter cells for the future cell wall, while in animal cells the cell membrane constricts to separates the parent cell into daughter cells. 4. Based on your data, what can you infer about the relative length of time an onion root-tip cell spends in each stage of cell division? The onion root tip will spend most of its lifetime in interphase. The least amount of its life will be between the phases of metaphase and telophase. 5. Define the following terms: of the two threadlike strands into which a chromosome divides longitudinally a. chromatid – "each during cell division. Each contains a double helix of DNA." b. chromatin – "the material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed. It consists of protein, RNA, and DNA." c. chromosomes – "a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes." d. kinetochore – "a complex of proteins associated with the centromere of a chromosome during cell division, to which the microtubules of the spindle attach." Part D. 1. What is the purpose of checkpoints in the cell cycle? The purpose of checkpoints in the cell cycle is to ensure that every process is being done correctly. 2. Identify the checkpoint for the following: a. G2 Checkpoint ___Cell undergoes apoptosis after it tried to fix the mistakes undergone in DNA replication b. G1 Checkpoint __Checks for amounts of nutrients in the cell c. G2 Checkpoint __Decides if it will divide- d. M Checkpoint __Ensures cell is attached to extracellular matrix e. _G2 Checkpoint __Ensures DNA replication occurred without any mutations to the DNA molecules f. M Checkpoint __Ensures the chromosomes attached themselves to spindles during metaphase Part E. 1. Releasing p53 (a tumor suppressor protein found in checkpoint __G1 Checkpoi_) induces DN_A___________________ damage. cell cycle arrest when it notices ___ 2. The expression of the E2F protein __ inhibits replicate. ___ the cell cycle to continue and DNA to