Wednesday, March 24, 2010

[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.


Nota Terkini