2.1.1 Stages of the Cell Cycle

• DNA replication occurs during the S phase of interphase.


  True
• Why do chromosomes condense during prophase?

  To prepare for division
• What is the main characteristic of metaphase?

  Chromosomes align at mid-plane
• Why is chromosome condensation necessary during prophase?

  To allow easy separation
• During anaphase, the spindle fibers shorten, pulling the chromatids to the opposite poles
• What reforms around each set of chromosomes during telophase?

  Nuclear envelope
• Stages of interphase in the correct sequence

  1️⃣ G1 (Gap 1)

  2️⃣ S (Synthesis)

  3️⃣ G2 (Gap 2)
• Match the stage of interphase with its purpose:

  G1 (Gap 1) ↔️ Growth and preparation for DNA replication

  S (Synthesis) ↔️ DNA replication

  G2 (Gap 2) ↔️ Final preparation for mitosis
• What is the longest phase of the cell cycle?

  Interphase
• Arrange the key events of prophase in the correct sequence.

  1️⃣ Chromosomes condense

  2️⃣ Nuclear envelope breaks down

  3️⃣ Mitotic spindle forms

  4️⃣ Centrosomes move to opposite poles
• What is the role of the mitotic spindle during prophase?

  To prepare to pull chromosomes apart
• DNA replication ensures each daughter cell receives a complete set of DNA
• What happens to sister chromatids during anaphase?

  They separate and move apart
• Chromosomes decondense into chromatin during telophase.


  True
• Interphase is the longest phase of the cell cycle
• The G2 phase ensures the cell is ready for division
• Centrosomes move to opposite poles during prophase.
• Spindle fibers attach to the centromeres of chromosomes during metaphase.
• The centromeres split, allowing the sister chromatids to separate during anaphase.
• What is the purpose of chromosomes decondensing during telophase?

  DNA becomes accessible
• Arrange the stages of the cell cycle in the correct sequence.

  1️⃣ Interphase (G1, S, G2)

  2️⃣ Prophase

  3️⃣ Metaphase

  4️⃣ Anaphase

  5️⃣ Telophase

  6️⃣ Cytokinesis
• What is checked during the G2 phase of interphase?

  DNA errors
• The nuclear envelope breaks down during prophase to allow interaction with the mitotic spindle.


  True
• Spindle fibers attach to the centromeres of chromosomes during metaphase.


  True
• Arrange the key events of metaphase in the correct sequence.

  1️⃣ Chromosomes align at the cell's midplane

  2️⃣ Spindle fibers attach to centromeres

  3️⃣ The cell monitors correct attachment
• What splits during anaphase to allow sister chromatids to separate?

  Centromeres
• Arrange the key events of telophase in the correct sequence.

  1️⃣ Chromosomes decondense into chromatin

  2️⃣ Nuclear envelope reforms

  3️⃣ Spindle fibers disassemble

  4️⃣ The cell prepares for cytokinesis
• DNA replication occurs during the G1 phase of interphase.

  False
• What is the first stage of mitosis?

  Prophase
• Chromosomes align at the cell's midplane during metaphase.

  True
• Sister chromatids separate during anaphase.


  True
• Events of telophase in the correct sequence

  1️⃣ Chromosomes decondense

  2️⃣ Nuclear envelope reforms

  3️⃣ Spindle fibers disassemble

  4️⃣ Preparation for cytokinesis
• What structure creates a new cell wall in plant cells during cytokinesis?

  Cell plate
• What is the role of the mitotic spindle in prophase?

  Prepares to pull chromosomes apart
• Why is correct attachment monitored during metaphase?

  To prevent premature anaphase
• What ensures each daughter cell receives a complete set of genetic material during anaphase?

  Chromosomes move to opposite poles
• Cytokinesis in animal cells involves the formation of a furrow.