Importance and Stages of Mitosis

Overview

• Objective: By the end of this lesson, understand the importance of mitosis and describe the stages of the cell cycle involving mitosis.

Key Concepts

Chromosomes and Genes

• Nucleus: Contains chromosomes made of DNA.
• Chromosomes:
  • Found in pairs in body cells (e.g., human cells have 23 pairs).
  • Carry genes; each chromosome may contain hundreds of genes.

Cell Division

• Purpose: Cells divide to form new cells for growth, repair, and reproduction.
• Methods: Mitosis and meiosis (focus on mitosis in this session).

The Cell Cycle and Mitosis

• Cell Cycle Stages:
  1. DNA Replication and Cell Growth:
     • DNA replicates to form two copies of each chromosome.
     • Cell grows and duplicates internal structures (e.g., mitochondria, ribosomes).
  2. Mitosis:
     • Chromosomes are pulled apart to opposite ends of the cell.
     • Nucleus divides.
  3. Cytoplasm Division:
     • Cytoplasm and cell membrane divide, forming two identical cells.

Functions of Mitosis

• Growth and Development:
  • Essential for growth of multicellular organisms (e.g., animals, plants).
• Repair:
  • Occurs when an organism repairs damage (e.g., healing of a broken bone).
• Asexual Reproduction:
  • Involved in reproduction without gametes (to be covered in detail later).

Additional Resources

• Revision Workbook: Available for further practice and questions on mitosis and the cell cycle.

Conclusion

• Key Learning: Understanding the importance and stages of mitosis allows for comprehension of essential biological processes like growth, repair, and reproduction.