stem cells

• What is found in the nucleus of both plant and animal cells?

  Chromosomes made of DNA
• How are body cells characterized in terms of chromosomes?

  Body cells contain two of each chromosome, meaning they are paired
• How many pairs of chromosomes do human body cells contain?

  23 pairs of chromosomes
• What are gametes in terms of chromosome pairing?

  Gametes have chromosomes that are not paired
• What is the relationship between chromosomes and genes?

  Chromosomes carry a large number of genes that determine many features
• Why is cell division necessary for multicellular organisms?

  Because they contain a large number of cells that need to divide
• What are the two processes by which cells can divide?

  Mitosis and meiosis
• What happens during the first stage of the cell cycle?

  The DNA replicates to form two copies of each chromosome
• What occurs to the chromosomes during the first stage of the cell cycle?

  The chromosome and its copy remain attached
• What internal structures does the cell copy during the first stage of the cell cycle?

  Mitochondria and ribosomes
• What happens during the second stage of the cell cycle?

  Mitosis takes place, pulling one set of chromosomes to each end of the cell
• What divides during the second stage of the cell cycle?

  The nucleus
• What occurs in the final stage of the cell cycle?

  The cytoplasm and cell membrane divide to form two identical cells
• How many identical cells are formed at the end of the cell cycle?

  Two identical cells
• What is the significance of mitosis in multicellular organisms?

  Mitosis is essential for growth and development
• When does mitosis occur in an organism?

  When an organism repairs itself, such as when a broken bone heals
• What role does mitosis play in asexual reproduction?

  Mitosis is involved in the process of asexual reproduction
• What are the stages of the cell cycle involving mitosis?

  1. DNA replication to form two copies of each chromosome
  2. Mitosis, where one set of chromosomes is pulled to each end of the cell
  3. Division of the cytoplasm and cell membrane to form two identical cells
• What are the functions of mitosis?

  • Essential for growth and development of multicellular organisms
  • Repairs damaged tissues (e.g., healing a broken bone)
  • Occurs during asexual reproduction