Aprotein contains 131 amino acids. how many bases will there
beon the mrna strand corresponding to these amino acids and how
doyou know?

393 nitrogenous bases

Explanation:

During the Translation process, the nitrogenous bases on the mRNA are read by the tRNA in triplets called codons.  Each codon codes for a specific amino acid which gets bonded to each other via peptide bonds and forms a peptide.

In the given question since the protein contains 131 amino acids these might have been coded by 393 nitrogenous bases shown below:

Since 1 amino acid coded by 3 nitrogenous bases  

so 131 amino acid will be coded by- 131 x 3 = 393 bases.

Thus, 393 bases are the correct answer.

answer and explanation;

volcanic rocks are igneous rocks which form from lava, molten rock which has been thrust out of a volcano onto the surface of a rocky body such as an asteroid, planet, or dwarf planet.  

plutonic rocks are igneous rocks which form from subterranean chambers of molten rock or magma. plutonic rocks make up the base of continental crust as well as oceanic crust. their slow rate of formation causes them to be coarse grained since there is plenty of time for large crystals to form before the magma solidifies into rock.

the textural difference is that plutonic rocks are more coarse grained than volcanic rocks. plutonic rocks are coarse grained while volcanic are fine grained ; glassey or fragmental. since fine and coarse are adjectives the decision as to whether a rock is fine or coarse grained is generally made on the bases of whether or not the individual crystals can be seen in most if the rock.