Teacher:Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.
Teacher: Now, understand the problem? Solve this instance: Passage: These chloroplasts, which can be traced back directly to a cyanobacterial ancestor, are known as primary plastids ('plastid' in this context means almost the same thing as chloroplast). All primary chloroplasts belong to one of three chloroplast lineages—the glaucophyte chloroplast lineage, the rhodophyte, or red algal chloroplast lineage, or the chloroplastidan, or green chloroplast lineage. The second two are the largest, and the green chloroplast lineage is the one that contains the land plants. Question: What does 'plastid' mean?
Student:
chloroplast