Learning Outcomes:
i. Students will define the cell cycle and understand its significance in cell growth and division.
ii. They will identify and describe the main phases of the cell cycle: Interphase and the Division phase, which includes mitosis and cytokinesis.
Summary of Lesson:
The cell cycle is the ordered series of events that a cell goes through between one division and the next. It includes periods of growth, DNA replication, and cell division. This lesson focuses on the two main phases of the cell cycle, highlighting how cells prepare for division and how they ensure that each new cell receives the proper genetic information.
i. The Cell Cycle: An Overview
The cell cycle is a repeating sequence of cellular growth and division during the life of a cell. It ensures that each new cell receives a full set of chromosomes and sufficient cellular machinery to function.
ii. Interphase: The Preparation Stage
Interphase is the longest part of the cell cycle and is divided into three sub-phases:
G1 Phase (First Gap): The cell grows and synthesizes proteins necessary for DNA replication.
S Phase (Synthesis): The cell replicates its DNA, so each new cell will have the correct genetic information.
G2 Phase (Second Gap): The cell continues to grow and prepares for division, making proteins and organelles needed for cell division.
iii.Division Phase: Mitosis and Cytokinesis
Mitosis: The nucleus divides into two nuclei, each with an identical set of DNA. Mitosis itself has several stages: prophase, metaphase, anaphase, and telophase.
Cytokinesis: The cytoplasm divides, resulting in two separate daughter cells, each with a nucleus and cellular organelles.
List of Important Questions for Self-Study:
i. What are the main purposes of the cell cycle?
ii. What occurs during the G1 phase of interphase?
iii. How is DNA replicated during the cell cycle?
iv. What are the key stages of mitosis and what happens during each?
v. How does cytokinesis differ in plant and animal cells?
vi. Why is the cell cycle important for growth and repair in multicellular organisms?
vii. How do cells ensure that genetic material is evenly divided during mitosis?
viii. What mechanisms do cells have to regulate the cell cycle?
ix. What might happen if there is an error during the cell cycle?
x. How do cancer cells differ from normal cells in terms of cell cycle control?
Important Terminologies Used in Lesson:
i. Cell Cycle: The series of events that take place in a cell leading to its growth, replication, and division into two daughter cells.
ii. Interphase: The phase of the cell cycle in which the cell spends the majority of its time and performs the majority of its purposes including growth and DNA replication.
iii. Mitosis: A part of the cell cycle when replicated chromosomes are separated into two new nuclei.
iv. Cytokinesis: The final stage of the cell cycle that separates the cytoplasm into two new cells.
v. Chromosome: A thread-like structure of nucleic acids and protein found in the nucleus, carrying genetic information in the form of genes.
