Question

a scientist discovers a new single - celled organism that has ribosomes but no nucleus. which classification is most accurate?
a. it is a eukaryote because all cells have ribosomes.
b. it is a prokaryote because it lacks a nucleus.
c. it is a plant cell because it has ribosomes.
d. it is an animal cell because it is single - celled.
which statement correctly compares prokaryotic and eukaryotic cells? *
a. prokaryotes have membrane - bound organelles, but eukaryotes do not.
b. both prokaryotes and eukaryotes have nuclei.
c. prokaryotes are always multicellular, while eukaryotes are always unicellular.
d. eukaryotes have a nucleus, while prokaryotes do not.

Explanation:

• Prokaryotes: Lack membrane - bound organelles (including a nucleus). Have ribosomes. Can be single - celled.
• Eukaryotes: Have membrane - bound organelles (including a nucleus). Can be single - or multi - celled.
• Option A: Prokaryotes have membrane - bound organelles? No. Prokaryotes lack membrane - bound organelles. Eukaryotes have them.
• Option B: Both have nuclei? No. Prokaryotes lack a nucleus (a type of membrane - bound organelle).
• Option C: Prokaryotes are always multicellular? No. Prokaryotes are usually single - celled.
• Option D: Eukaryotes have a nucleus (a membrane - bound organelle), prokaryotes do not. This is correct.

Answer:

D. Eukaryotes have a nucleus, while prokaryotes do not.