Given a scientific question, generate a correct answer to it.

Input: Consider Input: A complementary pair of chromosomes have genes for the same characteristics in the same location on the chromosome are known as?

Output: homologous chromosomes

Input: Consider Input: If only one atom of a specific type is present what is not used?

Output: subscript

Input: Consider Input: Hydras and sea anemones are examples of what form?
Output: polyp