Answer: Option B
Explanation: The first line of defense acts a barrier and does not allows the foreign materials to enter inside the body. It includes chemical and physical barriers that are always ready to protect the body from infection.
Example: Skin and mucous membrane.
Skin is largest organ and it acts as a barrier between pathogens and human body. It acts a waterproof material and the pathogens cannot get inside through skin unless the skin is broken.
Mucous membranes also acts as first line of defense and breaks the cell wall of many bacteria entering through the openings of the body.
So, skin and mucous membrane are the first line of defense.
Bacteria move using a tail like structure called flagellum .
Answer: C) Turbine
Explanation: Crude oil is turned into usable forms of energey by a Combustion Turbine. Hope this helped!
Answer:
A critical function of proteins is their activity as enzymes, which are needed to catalyze almost all biological reactions.
