Why animal-like organisms did not appear on Earth until after the first organisms that could photosynthesise had appeared.

800 million years ago , these clusters of specialized, cooperating cells eventually became the first animals, which DNA evidence suggests evolved around that time. Sponges were among the earliest animals.

The matched pairs are the following:

Neutralization --> products are always salt and water
Combustion --> Oxygen is one of the reactants, and a large amount of energy is released
Synthesis --> the reaction has at least two reactants and one product
Decomposition --> the reaction has one reactant and at least two products
Replacement --> one or more atoms replaces a part of a compound