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.
The tundra :)
hope this helps
Answer:
b positive
Explanation:
and this is the heavier gene that y
I think B would be the correct answer
Answer:
Pangaea was 1 huge super continent and with plate tectonics, the plates underneath the land began rubbing against each other and eventually eroded the rock and the pieces of land began to drift away from each other.
Explanation: