This is merely a biological reaction, I scolded myself, brought about by two years of celibacy.

A digester is a huge vessel where chemical or biological reactions are carried out.

A biological reaction caused by the proximity of a male, she thought bleakly.

Many of them catalyze important biological reactions, such as the ones in plants and animals that help turn food into energy.

She could tell that from her husband's biological reaction, in the small of her back.

So I think that vinegar tends to suppress most biological reactions.

The doctor had one hand on his forehead, mumbling, "A normal biological reaction."

"However, I can analyze the environmental logs to determine if the subspace field could have caused a biological reaction."

It's just the normal biological reaction of the male animal.

That makes it difficult to use for biological reactions.