Question

question #21
a student collects and records data about two different cells in a table.

based on an analysis of the information, which conclusion is supported with the best reasoning?
a cell a is a bacterial cell because it is microscopic.
b cell b is a plant cell because it is very large.
c cell a is a bacterial cell because it lacks membrane - bound organelles.
d cell b is an animal cell because it can be seen with the unaided eye.

question #22
a student compares three organisms, as shown in the table.

which inference about the organisms is accurately supported with evidence?
a all of the organisms are classified as prokaryotes because they are microscopic.
b all of the organisms are classified as eukaryotes because they are unicellular.
c e. coli and paramecium are classified as prokaryotes because both move using flagella.
d paramecium and amoeba are classified as eukaryotes because both have true nuclei.

Explanation:

Question #21

• Option A: Just being microscopic is not sufficient to classify a cell as bacterial. Many eukaryotic cells are also microscopic.
• Option B: Size alone (being “very large” is relative and the size range given for Cell B is \(10 - 100\ \mu m\)) is not a definitive characteristic to classify a cell as a plant cell. Plant cells have specific features like a cell wall, chloroplasts (in photosynthetic cells) etc. that are not indicated here.
• Option C: Bacterial cells (prokaryotes) lack membrane - bound organelles (including a nucleus). Cell A has no nucleus and no membrane - bound organelles, which is a key characteristic of prokaryotic (bacterial) cells.
• Option D: Cell B has a size range of \(10 - 100\ \mu m\), which is still microscopic (cells are generally microscopic, and being able to be seen with the unaided eye is not relevant here). Also, the presence of a nucleus and membrane - bound organelles does not specifically point to an animal cell (plant and fungal cells also have these features).

• Option A: Prokaryotes are defined by the absence of a true nucleus. Paramecium and Amoeba have a true nucleus, so they are not prokaryotes. Just being microscopic is not the defining characteristic of prokaryotes.
• Option B: Eukaryotes are defined by the presence of a true nucleus, not by being unicellular. E. coli is unicellular but is a prokaryote (lacks a true nucleus).
• Option C: E. coli is a prokaryote (lacks a true nucleus), but Paramecium is a eukaryote (has a true nucleus). Movement using flagella is not the defining characteristic of prokaryotes.
• Option D: Eukaryotes are organisms with a true nucleus. Paramecium and Amoeba both have a true nucleus, so they can be classified as eukaryotes.

Answer:

C. Cell A is a bacterial cell because it lacks membrane - bound organelles.

Question #22