Exchange of gases in fish is very efficient because of: the large surface area of the gills. the large surface area of the blood capillaries in each gill filament. the short distance required for diffusion – the outer layer of the gill filaments and the capillary walls are just one cell thick.
<span>tRNA - Transfer RNA: Brings amino acids to ribosomes during translation.
rRNA - Ribosomal RNA: With ribosomal proteins, makes up the ribosomes, the organelles that translate the mRNA.
<span>snRNA - Small nuclear RNA: With proteins, forms complexes that are used in RNA processing in Eukaryotas. (Not found in prokaryotes.)</span></span>
I think it would be either A or B but I am not sure.... If anything I think I would go with A.
Hope this helps
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.
