Just imagine for a moment that NASA's Curiosity Rover that landed on Mars in the summer of 2012 finds evidence of life at the cellular level on Mars. Imagine that their initial observations show that this Martian cell has a nucleoid region and also a cell wall, and measures 7 microns in diameter. Conclude what you can about this cell. Check all that apply.a. It is a prokaryote
b. It is a eukaryote
c. It must cause disease
d. It is a virus
e.It shares characteristics with cells on Earth

Nucleoid means nucleus-like and it is irregular center of prokaryotic cells and it doesn't have any membrane. 7 microns diameter is not necessarily a prokaryote attribute and they usually range from 0.1 to 5 microns while eukaryotic cell range from 10 to 100 microns in diameter. You just need to memorize that prokaryotes generally smaller than eukaryotes. (Fun fact smallest eukaryotic organism Ostreococcus only measures 0.8 microns across. It is also not a virus since this organism have cell wall and nucleoid. Our theoretic cell also shares characteristics with cells on Earth such as cell wall and nucleoid. And we can't say "it must cause disease" without knowing other attributes and evidence is insufficient.