The main function of white blood cells is (a)To help red blood cells in the transportation of oxygen and carbon dioxide. (b)To clot the blood at the time of injuries (c)To accelerate the production of red blood cells in the bone marrow (d)To defend the body against infections

What type of questions asked from the lesson of magnetic effect of electric current 

Wavelength of green light is

A) 400-450 nm

B) 500-550 nm

C) 660-720 nm

D) 720-800 nm

What is the difference between anaerobic & aerobic respiration? Name some organism that uses the aerobic mode of respiration?

What are the main components of our environment? Explain each of them briefly.

What are examples of hydrotropism plants?