Cell cycle

• What is the cell cycle?

  Regular cycles of growth followed by division
• What are the three distinct stages of the cell cycle?

  Interphase, mitosis, and cytokinesis
• What occurs during interphase?

  Preparation and growth of the cell
• Which stage is the longest in the cell cycle?

  Interphase
• What are the phases within interphase?

  • G1: First growth phase
  • S: Synthesis phase (DNA replication)
  • G2: Second growth phase
• What happens during the G1 phase?

  Cell increases in size and synthesizes proteins
• What occurs during the S phase?

  Replication of DNA by semi-conservative replication
• What happens during the G2 phase?

  Organelles grow and divide
• What is mitosis?

  Nucleus divides into two identical nuclei
• What is cytokinesis?

  Division of the cytoplasm into two cells
• How does the DNA content change during the cell cycle?

  DNA mass increases during S phase, then splits
• What are the key features of mitosis?

  • Nucleus divides into two
  • Each nucleus has identical chromosomes
  • Essential for growth, repair, and asexual reproduction
• What are daughter cells?

  New cells formed from cell division
• What is the significance of mitosis?

  It produces identical daughter cells for growth
• What causes cell mass increase during the cell cycle?

  G1 and G2 phases in interphase
• What happens to cell mass during cytokinesis?

  Mass returns to original as cell divides
• When does DNA mass increase in the cell cycle?

  During the S phase of interphase
• What does the graph of DNA content during the cell cycle show?

  DNA mass doubles during S phase, then splits
• What are the events that occur in the cytoplasm and nucleus during cell division?

  • Nucleus divides during mitosis
  • Cytoplasm divides during cytokinesis
  • Organelles are distributed to daughter cells
• Interphase

  The period between cell divisions during which the cell grows, replicates its DNA, and prepares for cell division.
• G1 phase

  The first stage of interphase, during which the cell grows and prepares for DNA replication.
• S phase

  The stage of interphase where DNA replication occurs.
• G2 phase

  The final stage of interphase, during which the cell prepares for cell division.
• Chromatin

  a complex of DNA and proteins that make up the chromosome.
• Mitosis

  a type of cell division that results in two daughter cells, each having the same number and kind of chromosomes as the parent cell.
• Prophase

  The stage of mitosis where chromosomes condense and become visible, the nuclear envelope breaks down, and the spindle fibers form.
• Metaphase

  The stage of mitosis where chromosomes line up at the centre of the cell, attached to the spindle fibres.
• Anaphase

  The stage of mitosis where sister chromatids separate and move to opposite poles of the cell.
• Telophase

  The final stage of mitosis where the nuclear envelope reforms around each set of chromosomes.
• Cytokinesis

  The stage of cell division where the cytoplasm divides to form two daughter cells.
• Cytoplasmic separation

  The process where the cytoplasm divides to form two daughter cells.
• Cleavage

  The process where the cytoplasm divides to form two daughter cells, characteristic of animal cells.
• Cell plate formation

  The process where a cell plate forms in plant cells, leading to the separation of the cytoplasm.
• New cell membrane formation

  The process where a new cell membrane forms around each set of chromosomes.
• Chromosome

  a thread-like structure made up of DNA and proteins, which carries genetic information.
• Sister chromatids

  Two identical copies of a chromosome that share a common centromere.
• Centromere

  a special region on a chromosome where the spindle fibre attaches during cell division.
• Spindle fibres

  Protein structures that form during cell division, attaching to the centromere and helping to separate chromosomes.
• Checkpoints

  The mechanisms that regulate the cell cycle to ensure accurate and timely cell division.
• G1 checkpoint

  A checkpoint that occurs at the end of the G1 phase, ensuring that DNA damage is repaired before DNA replication begins.