Because it allows only certain substances to permeate. If it was totally permeable that would be good enough to having no barrier as it would let everything though. Totally impermeable means that nothing would get through.
Answer:
C. makes the most sense so I hope I'm right
Explanation:
If this isn't correct I am so so so sorry!
So white blood cell’s(WBCs for short) main job is to fight infections.
They do this by swallowing the infection.
You see,WBCs do not have a permanent shape.this means that they enlarge and decrease size of parts of their body.So they grow two long arm like structures called pseudopodia which swallow the infection.(pseudopodia means false feet).
You can see the process in the photo I attached from google
Answer:
Charles Darwin had a theory that states that evolution happens by natural selection. Individuals in a species show variation in physical characteristics. ... As a consequence those individuals most suited to their environment survive and, given enough time, the species will gradually evolve.
A. "power plant" that provides energy for cells
The food we eat is brought to the mitochondria and broken down. Once it gets broken down the mitochondria converts the food into ATP
Hope this helped!
~Just a girl in love with Shawn Mendes