The hiker followed the north trail a distance of two kilometers in thirty minutes.
Cell membranes serve as barriers and gatekeepers. They are semi-permeable, which means that some molecules can diffuse across the lipid bilayer but others cannot. Small hydrophobic molecules and gases like oxygen and carbon dioxide cross membranes rapidly.
C)
Explanation:
They are not able to synthesise their own food
The phagocytotic barrier, which is a part of innate immunity best describes the above scenario.
Answer: Option C
<u>Explanation:</u>
The largest organ of the body is the skin, similarly the skin also an immune barrier to the body. If there is any damage in the skin , its pH gets compromised and there it calls in for a microbial attack.
When there is a cut in the skin and bacteria enter the body, the immune system responds. First, macrophages approach the area of the cut. Next, the macrophages surround any bacterial cells and engulf them, the Phagocytosis barrier which is the part of the innate immunity
Amino acids are the building blocks that make up proteins.
