Answer:
A reaction that joins the nuclei of two atoms into one
Explanation:
Think of the words "nuclear fusion".
Nuclear = "relating to a nucleus"
Fusion = "joining"
So, nuclear fusion is the joining of two nuclei into one.
A and B are wrong, because chemical reactions involve electrons.
D is wrong, because the splitting of a nucleus is fission.
A, because it the constant variable
1. <span>Protists are the members of an informal grouping of diverse eukaryotic organisms that are not animals, plants or fungi. They do not form a natural group, or clade, but are often grouped together for convenience, like algae or invertebrates.
2.</span><span>Todays protists include groups whose ancestors were among the very last to split from the organisms that gave rise to plants, animals, and fungi.</span>
Answer:
Pituitary gland is known as the master gland
