Cell division and diversity

• What are the three stages of the cell cycle?

  Mitosis, cytokinesis, and interphase
• What are the four stages of mitosis?


  Prophase, metaphase, anaphase, and telophase
• What occurs during cytokinesis?


  The parent and replicated organelles move to opposite sides of the cell and the cytoplasm divides
• What happens during interphase?


  The cell grows and prepares to divide, replicating chromosomes and some organelles
• What happens to the nuclear envelope during prophase?


  It breaks down and subsequently disappears
• What is the role of centrioles during prophase?


  They move to opposite poles of the cell for spindle formation
• How do chromosomes behave during metaphase?


  They move to the equator and attach to spindle fibres via centromeres
• What occurs during anaphase?


  The sister chromatids are separated
• What happens during telophase?


  The nuclear envelope reforms, creating two daughter cells
• How does meiosis contribute to genetic variation?


  Through crossing over of chromatids and independent assortment of chromosomes
• What is the difference between meiosis I and meiosis II?


  Meiosis I separates homologous chromosomes, while meiosis II separates sister chromatids
• What are the stages of meiosis I?


  Prophase I, metaphase I, anaphase I, and telophase I
• What are examples of tissues in plants?

  Xylem and phloem
• What is the function of xylem tissue?


  To transport water and minerals and provide structural support
• What are the characteristics of xylem vessels?


  They are long cylinders made of dead tissue with open ends, thickened with lignin
• What is the role of phloem tissue?


  Involved in translocation of food substances and nutrients from leaves to storage organs
• How are phloem tubes formed?


  By elongating cells that line up end-to-end to form a long tube
• What are sieve plates in phloem tissue?


  Perforated structures at the ends of phloem cells
• What is the function of companion cells in phloem?


  To mediate the movement of photosynthesis products in the tubes
• What are the two types of epithelial tissue?


  Squamous epithelium and ciliated epithelium
• What is the function of squamous epithelium?


  To create a smooth surface by fitting closely together
• What is the role of ciliated epithelium?


  To move mucus produced by goblet cells along
• Where is ciliated epithelium found?


  In the trachea, bronchi, and oviducts
• What is the function of connective tissue?


  To provide support and hold various structures together
• What is the primary function of muscle tissue?


  Specialized for movement through contraction
• What is the role of nervous tissue?


  Specialized for impulse conduction
• What are stem cells?


  Undifferentiated cells that can develop into various kinds of cells
• What are some uses of stem cells in medicine?


  Repair of damaged tissues and treatment of neurological disorders
• What is differentiation?


  The process by which a cell specializes to carry out a particular function
• Where are stem cells found in the body?


  In the bone marrow
• What is the role of erythrocytes?


  Transporting oxygen in the blood
• Why are erythrocytes relatively short-lived?


  Because they are constantly destroyed and created
• What is the role of neutrophils?


  Involved in attacking and destroying foreign microorganisms
• What is the function of palisade cells?


  Specialized for photosynthesis and contain many chloroplasts
• What is the role of root hair cells?


  To increase surface area for water and mineral absorption
• Why are root hair cells short-lived?


  Because they are constantly produced in the root tip
• What is the function of guard cells?


  To control the opening and closing of stomata
• How do guard cells respond to water influx?


  They alter their shape, causing stomata to open
• What is the difference between haploid and diploid cells?


  Haploid cells have half the number of chromosomes compared to diploid cells
• What is the significance of meristems in plants?


  They are regions where cell division occurs at a high rate