Which mRNA base must be the one which is substituted in the sixth codon that would result in the change of GLU (glutamic acid), whose mRNA codon is GAG into Val

The mRNA base that must be substituted is A. A is substituted by U.

Explanation: In the sixth position of the beta chain of hemoglobin, valine replaces glutamine acid. The effect of this substitution is an abnormal red blood cells with a sickle shape. Every amino acid is coded for by a least one codon. A codon is a triplet of nucleotides in a mRNA. The mRNA codons for glutamic acid are GAA and GAG, while the mRNA codons for valine are GUU, GUC, GUA and GUG.

When the base Adenine (A) in the mRNA codon GAG which codes for glutamic acid is substituted by the base Uracil (U), the new mRNA codon will be GUG which codes for valine.

what bodys are there orbiting?

wild parsnip is a perennial plant which reproduces rapidly in areas which have no sign of agricultural activity such roadside or at no tillage open areas. it's considered invasive because it can inhibit the growth of another plant  and its reproduction is fast. there are several harmful effects of this invasive plant although its taproot is edible since it is a member of the carrot family. wild parsnips can cause skin blistering when in contact because of the chemicals it contains, second it inhibits the growth of other plants, it will restrict the growth of animals when eaten and lastly, it drives away natural pollinators like bees.