Cell Cycle
Unit 3: Cell Cycle—Lesson 3.1 Cell Cycle and Cell Divisions
Page 2: Introduction
Cells as Building Blocks
Multicellular organisms are composed of cells that form tissues, organs, and organ systems.
Organisms rely on cellular organization for proper functioning.
Cellular Reproduction
All sexually reproducing multicellular organisms start as a single cell.
Growth and development involve continuous reproduction and specialization of cells.
Understanding Components
Discuss the significance of each model component.
Explore the stepwise nature of cell cycle events.
Page 6: Genetic Material of Cells
DNA Structure and Function
DNA is the genetic material found in the nucleus.
Composed of nucleotides forming base pairs that code for traits.
Forms of DNA
Chromatin: DNA in a relaxed state during interphase.
Chromosomes: Highly condensed DNA during cell division.
Page 7: Chromosome Structure
Diploid Organisms
Chromosomes occur in homologous pairs (e.g., humans have 46 chromosomes).
Sister chromatids are identical copies linked by a centromere.
Page 8: Chromatin to Chromosome Transition
DNA Organization
Chromatin condenses into chromosomes during cell division.
Each half of a chromosome is a chromatid.
Page 9: Introduction to Cell Cycle
Life Cycle of Cells
Cells have their own life cycle, known as the cell cycle.
The cell cycle describes how cells grow, develop, and reproduce.
Page 10: Overview of the Cell Cycle
Phases of the Cell Cycle
Comprised of interphase, M phase, and cytokinesis.
Interphase is when the cell prepares for division.
Page 11: Interphase
G1 Phase
Growth of cytoplasm and doubling of organelles.
High protein synthesis and preparation for DNA replication.
Page 12: S Phase
DNA Replication
The cell synthesizes a copy of its DNA.
Essential for producing daughter cells with identical genetic material.
Page 13: G2 Phase
Preparation for Division
Continued growth and production of materials for cell division.
Ensures the cell is ready for mitosis or meiosis.
Page 14: Mitosis and Meiosis
Nuclear Division
Mitosis for somatic cells; meiosis for gametes.
Both processes involve specific phases for genetic material distribution.
Page 15: Cytokinesis
Cytoplasm Division
Different processes in animal (cleavage furrow) and plant cells (cell plate).
Results in the formation of daughter cells.
Page 16: Cell Cycle Checkpoints
Importance of Checkpoints
Cells halt the cycle to correct errors or undergo apoptosis if errors are severe.
Checkpoints include G1-to-S, G2-to-M, and metaphase checkpoints.
Page 17: G1-to-S Checkpoint
Cell Readiness Assessment
Ensures the cell is large enough and DNA is undamaged before proceeding.
Page 18: Key Points
Summary of the Cell Cycle
The cell cycle describes cell growth, development, and reproduction.
Interphase is crucial for preparation, while cytokinesis divides the cytoplasm.
Page 19: Check Your Understanding
Identify Phases and Checkpoints
Questions to reinforce understanding of cell cycle phases and checkpoints.
Page 20: Challenge Yourself
Critical Thinking Questions
Differentiate between mitosis and meiosis.
Explain the necessity of cell cycle checkpoints and the role of