[Biology Form 4] Plant & Growth

1. Name the phase in which the:
   a) centromeres of chromosomes are lined up at an imaginary plane across the middle of the cell
   
   • Metaphase
   
   b) nucleolus re-forms and the spindle fibres disappear
   
   • Telophase
   
   c) chromosomes are visible as duplicated, thick and short thread-like structures
   
   • Prophase
   
   d) cell is about ready to divide by cytokinesis
   
   • Telophase
   
   e) cell is gathering its energy to begin active mitosis
   
   • Interphase
   
   f) two sister chromatids of each chromosome separate at the centromere
   
   • Anaphase
   
   
   
2. 
   
   
   Based on the diagram, answer the following questions:
   
   a) Name the tissue found at the tip of a plant root.
   
   • Apical meristem
   
   b) Where else in a plant is this tissue usually found?
   
   • Shoot tip
   
   c) State the characteristics of the cells found in the tissue named in (a).
   
   • Very small in size / isodiametric in shape /contain a dense cytoplasm / have a large nucleus
   
   d) When mitosis occurs in these cells, primary growth, which records an increase in length and height, results in the root and shoot.
   
   e) For secondary growth in a plant, mitosis occurs in the vascular cambium, a tissue found between the xylem and phloem tissue in dicotyledons.
   
   f) Mitosis is important for growth because it increases the number of cells in the organism.