cell cycle

• What is the purpose of mitosis in living organisms?


  To create identical copies of a cell for growth, repair, or asexual reproduction
• What type of cells are referred to as diploid cells?


  Cells that contain chromosomes in pairs
• How many pairs of chromosomes do human cells contain?


  23 pairs of chromosomes
• What happens to a diploid cell during mitosis?


  It divides into two identical diploid cells
• In what situations does mitosis occur?


  When an organism grows, repairs itself, or reproduces asexually
• What are the two main phases of the cell cycle?


  Interphase and the mitotic phase
• What occurs during interphase of the cell cycle?


  The cell increases energy stores, grows, replicates organelles, and copies DNA
• What are the two processes that occur during the mitotic phase?


  The nucleus divides into two daughter nuclei and the cell divides into two daughter cells
• What does the term mitosis specifically refer to?


  The division of the nucleus
• What is the term for the division of the cell?

  Cytokinesis
• What is chromatin?


  Dark material in the nucleus where chromosomes are not visible as distinct structures
• What happens to chromosomes during interphase?


  They are replicated
• What are sister chromatids?


  Two identical molecules of DNA joined at the centromere
• What is the centromere?


  The point where sister chromatids are joined
• Why are chromosomes not visible as distinct structures during interphase?


  Because they have a loose open structure called chromatin
• How many pairs of chromosomes do humans have that undergo replication during interphase?


  23 pairs of chromosomes
• What is the overall process of mitosis and cytokinesis in the cell cycle?


  • Mitosis: Division of the nucleus into two daughter nuclei
  • Cytokinesis: Division of the cell into two daughter cells
  • Both occur during the mitotic phase of the cell cycle
• What are the key events that occur during interphase?


  1. Cell increases energy stores
  2. Cell grows in size
  3. Organelles are replicated
  4. DNA is copied
• What is the relationship between chromatin and chromosomes during interphase?


  • Chromatin is the loose structure of DNA
  • Chromosomes are not visible as distinct structures
  • Chromatin allows for transcription and replication
• What happens to chromosomes during the replication process in interphase?


  • Each chromosome is replicated
  • Results in two identical DNA molecules called sister chromatids
  • Sister chromatids are joined at the centromere
• Who is the presenter of the biology video discussing the cell cycle and mitosis?

  Miss Estri
• What is the main focus of the video presented by Miss Estri?


  The cell cycle, mitosis, and the mitotic index
• What type of cells does the video focus on for cell division?

  Eukaryotic cells
• What is the alternative to mitosis mentioned in the video?

  Meiosis
• How do prokaryotic cells replicate?


  By binary fission
• How do viruses replicate?


  By injecting their nucleic acid into host cells
• What are the main stages of the cell cycle?


  • Interphase (G1, S, G2)
  • Nuclear division (mitosis or meiosis)
  • Cytokinesis
• What percentage of the cell cycle is typically interphase?


  About 90% or longer
• What happens during the G1 phase of the cell cycle?


  All organelles double and the cell grows in size
• What occurs during the S phase of the cell cycle?


  DNA replication happens
• What is the purpose of the G2 phase in the cell cycle?


  To check for potential mutations in the replicated DNA
• What happens if a mutation is detected during the G2 phase?


  The cell is destroyed to prevent potential harm
• What are the four key stages of mitosis?


  1. Prophase
  2. Metaphase
  3. Anaphase
  4. Telophase (or Tease)
• How many rounds of division occur during mitosis?


  One round of division
• What type of cells are produced by mitosis?


  Genetically identical diploid cells
• What is a specific example of mitosis in action mentioned in the video?


  Clonal expansion and differentiation of B cells in immunity
• What happens to chromosomes during prophase?


  • Chromosomes condense and become visible
  • Centrioles move to opposite poles
  • Nuclear envelope starts to disintegrate
• What occurs during metaphase?


  • Chromosomes align along the equator (metaphase plate)
  • Spindle fibers attach to chromatids at the centromere
  • No nucleus is present
• What happens during anaphase?


  • Spindle fibers retract, putting tension on the centromeres
  • Centromeres divide, pulling chromatids to opposite poles
  • ATP is required for this process
• What occurs during telophase?


  • Chromosomes become longer and thinner
  • Spindle fibers disintegrate
  • Nuclear envelope reforms