Prokaryotic cells are smaller than eukaryotic cells. What is a plausible explanation?

Question

A.  Prokaryotic cell walls limit their cell growth.
B.  Prokaryotes lack the genetic material needed for protein synthesis.
C.  Eukaryotes have compartmentalization, which allows for specialization.
D.  Prokaryotes have more diverse energy sources.
E.  Eukaryotes are immobile allowing them to grow larger.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
· What key words does the question contain and what do they mean?

Gather Content
· What do you know about the structure of cells? How does it relate to the question?

Consider Possibilities · What other information is related to the question? Which information is most useful?

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

C.  Eukaryotes have compartmentalization, which allows for specialization.

Clarify Question
· What is the key concept addressed by the question?
        o The question asks about the difference in size between prokaryotic and eukaryotic cells.
· What type of thinking is required?
        o You are being asked to apply your knowledge of the structure of prokaryotic and eukaryotic cells to explain why the prokaryotic cells are smaller.
· What key words does the question contain and what do they mean?
        o Prokaryotic cells – these are bacterial cells that contain DNA and the machinery for metabolism and replication, but no organelles.
        o Eukaryotic cells – these cells can be single celled organisms or part of a larger multicelled organism.  They contain a nucleus and other organelles.

Gather Content
· What do you know about the structure of cells? How does it relate to the question?
        o Prokaryotic cells do not contain organelles while eukaryotic cells do contain organelles.
        o Eukaryotes are diverse organisms, some can move (animals and some protists) while others have cells walls (fungi, plants, some protists).  Some are multicellular (plants, animals, and fungi) while some can be single celled (plants, protists, fungi).

Consider Possibilities · What other information is related to the question? Which information is most useful?
        o While prokaryotes are single celled and do not contain organelles they have the normal functions of all cells, namely they can replicate, produce energy through metabolism, and have a plasma membrane.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o Some eukaryotes can move and some have a cell wall.  Bacteria can make proteins and their choice of energy source should not influence their size.  The best answer is that eukaryotic cells all contain organelles such as a nucleus, mitochondria, chloroplasts, lysosomes, etc.  These internal structures take up space making eukaryotic cells larger than prokaryotic cells.

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?         o This question asked you to apply your understanding of the differences in the cell structure of prokaryotes and eukaryotes to explain why eukaryotes are larger. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you have trouble recalling that eukaryotes have internal organelles?  Did you forget that many eukaryotes can move or have cell walls like prokaryotes so this would not explain the difference in size?  Did you think that prokaryotes could not make proteins, an essential function for any living cell?