University:
Sam Houston State University
Course:
BIOL 2413 | General Zoology
Academic year:

2022
Views:

430

Pages:

12
Author:

Giselle A.

Cell Structure and Function The Cell Cycle Agriscience Instructor: Student Objectives    1) Diagram and label the cell cycle and understand of each phase. 2) Identify cells in each stage of the cell cycle. 3) Understand how the cell controls cell division. Understanding the Cell Cycle  1. 2. 3. There are three major stages to the cell cycle – Interphase, Mitosis and Cytokinesis. Interphase encompasses the phases of G1 (Growth 1), S (DNA Synthesis) and G2 (Growth 2) phase. Mitosis encompasses the phases of prophase, metaphase, anaphase and telophase. Cytokinesis (cytoplasm divides) The Cell Cycle in Action! Why do we care about cell division?  A) Cell division is a process of reproducing cells. This occurs during growth, repair and development of tissues. What is the cell cycle?  Repeating sequence of cellular growth and division throughout the life of an organism Interphase – an Overview    1st Growth Phase DNA Synthesis Phase 2nd Growth Phase Phases of Interphase  A) 1st Growth Phase = (G1)    1. Cell grows rapidly and carries out routine functions 2. Phase takes most of the cell’s life 3. Muscle and nerve cells never divide, so they remain in G1 Phases of Interphase (cont.)  B) Synthesis Phase (S)   1. Cell’s DNA is copied 2. At the end of the stage, each chromosome consists of 2 chromatids attached @ a centromere. Phases of Interphase (cont.)  C) Second Growth Phase (G2)   1. Hollow microtubules are assembled 2. Microtubules are used to move chromosomes during mitosis Second Phase of the Cell Cycle D) Mitosis 1. Nucleus is divided into 2 nuclei 2. Each nucleus ends up with the same number of chromosomes as the original cell. 3. Includes prophase, metaphase, anaphase and telophase. Final Stage of the Cell Cycle Cytokinesis 1. During this final stage, the cytoplasm divides.