Question

a student observes this cell under the microscope. he is discussing the structure indicated by the arrow with his lab partner. what would be the most likely classification of the cell pictured? what evidence supports your choice? a this cell is eukaryotic because it is enclosed in a cell membrane and does not have a cell wall. b this cell is prokaryotic because it contains ribosomes to carry out protein synthesis. c this cell is prokaryotic because it contains a nucleus with circular dna. d this cell is eukaryotic because it contains membrane - bound organelles such as lysosomes and vacuoles.

Explanation:

• Option A: Both prokaryotic and eukaryotic cells have a cell membrane. The absence of a cell wall is not a definitive characteristic for classifying a cell as eukaryotic. Plant cells (eukaryotic) have cell walls, while animal cells (eukaryotic) do not. So, this option is incorrect.
• Option B: Both prokaryotic and eukaryotic cells contain ribosomes for protein synthesis. Ribosomes are not a distinguishing feature between prokaryotes and eukaryotes. So, this option is incorrect.
• Option C: Prokaryotic cells do not have a nucleus. Their DNA is in the form of a circular chromosome located in the nucleoid region (not enclosed by a membrane). Eukaryotic cells have a nucleus with linear DNA (in most cases, except for some organellar DNA like mitochondrial DNA). So, this option is incorrect.
• Option D: Eukaryotic cells are characterized by the presence of membrane - bound organelles such as lysosomes, vacuoles, mitochondria, endoplasmic reticulum, etc. Prokaryotic cells lack these membrane - bound organelles. This is a key difference between prokaryotic and eukaryotic cells.

Answer:

D. This cell is eukaryotic because it contains membrane - bound organelles such as lysosomes and vacuoles.