First eukaryotic chromosome sequenced What was the first eukaryotic chromosome to be completely sequenced and assembled?

Introduction / Context:
Sequencing a complete eukaryotic chromosome was a landmark achievement, showcasing strategies for assembling larger, more repetitive genomes compared with bacteria. Yeast, with its compact genome and genetic tools, served as a key model organism for this work.

Given Data / Assumptions:

• Question asks specifically for the first eukaryotic chromosome sequenced.
• Several plausible eukaryotic chromosomes are listed.
• Historical sequencing efforts proceeded from simpler to more complex eukaryotes.

Concept / Approach:
The first fully sequenced eukaryotic chromosome was S. cerevisiae chromosome III, reported in the early 1990s. This project provided a proof of concept for systematic chromosome-by-chromosome approaches that later enabled complete yeast and higher eukaryote genomes.

Step-by-Step Solution:
Recall organism: baker’s yeast (S. cerevisiae).Recall specific chromosome: chromosome III.Choose the option naming yeast chromosome III.

Verification / Alternative check:
Human chromosomes (e.g., 22) and plant chromosomes were completed later, after yeast served as a prototype system.

Why Other Options Are Wrong:

• Yeast chromosome XI and Arabidopsis chromosome IV were sequenced later.
• “None of these” is incorrect because yeast chromosome III fits the historical record.

Common Pitfalls:
Assuming human chromosomes were first due to notoriety; in reality, simpler eukaryotes led the way.

Final Answer:
Yeast (Saccharomyces cerevisiae) chromosome III.