Someone please help i do not understand urgent

When does dna replication(make a copy of itself)?

One statements is an example of a scientific observation. another statement is an example of a scientific explanation. identify the correct statement for each category to illustrate how scientific explanations are inferred from scientific observations.

The wings of insects, birds, and bats evolved independently but carry out similar functions. this is an example of a. analogous structures. b. embryonic structures. c. vestigial structures. d. homologous structures.