Biological Symmetry

  1. What is biological symmetry?
    Biological symmetry is the arrangement of body parts about the central axis which ends in the creation of geometric designs.
  2. What is an axes?
    An axes is an imaginary line which passes through the center of the body.
  3. What are the extremitites of axes called?
    • The extremities of axes are called poles. Which maybe similar (homopolar) or different (heteropolar).
    • Example: anteria and posteria
  4. Name the three types of biological symmetry.
    • They are:
    • Spherical Symmetry (ball)
    • Radial Symmetry (wheel)
    • Bilateral Symmetry
  5. What is speherical symmetry?
    • It is any plane through the centre of the body producing halves which are mirror images of each other.
    • This type favours rolling or floating movements.
  6. What is radial symmetry?
    • Radial Symmetry are parts which radiate from the central or longitutual axis; consentric parts (havin same center).
    • This type favours sessile or sedentary mode of living
    • Stationary organisms who dont move about. eg coral and sponges.
    • It also enables animals to respond equally on all sides.
  7. What is bilateral symmetry?
    • Bilateral symmetry consits of only one plane (mid-saggittal) which divides the organism in halves which are mirror images of each other.
    • This type of symmetry is marked by head specialization called Cephalisation.
    • Bilateral symmetry favours rapid, forward motion.
  8. What is Cephalisation?
    Cephalisation is the concentration of sense organs in the head region.
Card Set
Biological Symmetry
Talking about the different types of biological symmetry