What phrase describes a good scientific question? has a wide focus
addresses a gap in knowledge
does not lead to a testable hypothesis
has a simple yes or no answer

addresses a gap in knowledge

Explanation:

Every scientific experiment begins with an observation or a question. This question is called a scientific question. A scientific question is a question that helps the scientist or experimenter get to the root of an investigation, like a head start. One important character a scientific question is that it must be able to be tested via experimentation.

In this question, the phrase that best describes a good scientific question is that it should ADDRESS A GAP IN KNOWLEDGE. This means that it should aim at filling a void or contribute to knowledge.

the answer is d.) homologous; have mammary glands

a. to encourage apoptosis