Which one of the following acts as a communication system?

A. Blood

B. Nerve

C. Lymph

D. Enzymes

Please do not use chat terms. Example: avoid using "grt" instead of "great".

You can do it
  1. The age of a tree can be determined by
  2. pH of blood remains constant due to
  3. Wallace's line is a line
  4. The liver destroys old
  5. Which of the following is a vector-borne disease for which a special programme has been launched by…
  6. One of the following is called a feminine hormone. Which one is it?
  7. Formation of blood
  8. Niche' refers to
  9. Scurvy is prevented by vitamin
  10. The tear glands help us in
  11. Coagulation of blood in vessels is prevented during normal circulation by
  12. The insect vector for the disease Leishmaniasis is
  13. Late Blight' is a disease that affects the _______ crop.
  14. Haemophilia is a hereditary disease carried by
  15. Sterilization, as the means for the prevention of sepsis in surgery, was practised and advocated by
  16. Most of the enzymes are
  17. Which one of the following cells helps in storing water and food materials?
  18. What is the other name for the brain?
  19. Appearance of offspring resembling their remote ancestor is called
  20. The equilibrium and co-ordination is looked after by which part of the brain?
  21. The plant that is dispersed with the help of water is
  22. Fat present below the skin surface in our body acts as a barrier against
  23. The first sign of life made its appearance on the earth about
  24. Spontaneous generation signifying the development of living organisms from non-living has been termed
  25. Insulin is produced in the human body by the
  26. What is the colour of the outer portion of the spinal cord?
  27. The first person to observe the bacteria, protozoa and spermatozoa under the microscope was
  28. Typhoid is a disease caused by
  29. Gases of Jupiter' are
  30. What do you mean by the term fauna?