Chapter 1, Problem 16RE

RECALL List five differences between prokaryotes and eukaryotes.

Interpretation Introduction

Interpretation:

The five differences between eukaryotes and prokaryotes are to be listed.

Concept introduction:

The term “prokaryote” is derived from two Greek words, pro and karyon. Pro means before and karyon means kernel or nut.

The eukaryotes are organisms that possess a true nucleus and they evolved from prokaryotes.

Although the eukaryotes evolved from prokaryotes, their characteristics are different from each other.

Answer to Problem 16RE

Solution:

$\begin{array}{lll}\text{Chracters}\hfill & \text{Prokaryotes}\hfill & \text{Eukaryotes}\hfill \\ \begin{array}{l}\text{Nucleus}\hfill \end{array}\hfill & \begin{array}{l}\text{Well defined }\\ \text{nucleus is absent }\end{array}\hfill & \begin{array}{l}\text{Well defined }\\ \text{nucleus is present}\text{.}\end{array}\hfill \\ \text{Plasma membrane}\hfill & \begin{array}{l}\text{Only one }\\ \text{plasma membrane }\\ \text{is present}\text{.}\end{array}\hfill & \begin{array}{l}Aninternal\\ membranesystem\\ ispresent.\end{array}\hfill \\ \text{Membrane bound organelles}\hfill & \begin{array}{l}\text{They do not possess}\\ \text{ any membrane }\\ \text{bound organelles}\text{.}\end{array}\hfill & \begin{array}{l}\text{Membrane bound }\\ \text{organelles }\\ \text{ are present}\end{array}\hfill \\ \text{Size}\hfill & \begin{array}{l}\text{They have smaller size than }\\ \text{eukaryotes}\text{.}\end{array}\hfill & \begin{array}{l}\begin{array}{l}\text{Eukaryotes are}\\ \text{ larger in size}\text{.}\end{array}\hfill \end{array}\hfill \\ \text{Organization of cells}\hfill & \begin{array}{l}\text{They are single-celled}\\ \text{ organisms}\end{array}\hfill & \begin{array}{l}\text{They can be single celled}\\ \text{ organisms or }\\ \text{multi-celled organisms}\\ \end{array}\hfill \end{array}$

Explanation of Solution

The earliest cells that were present on the surface of Earth were prokaryotes. The prokaryotes eventually evolved into eukaryotes. The eukaryotes have membrane-bound organelles that are absent in prokaryotes. The differences between eukaryotes and prokaryotes, based on certain characters, are listed below:

$\begin{array}{lll}\text{Chracters}\hfill & \text{Prokaryotes}\hfill & \text{Eukaryotes}\hfill \\ \begin{array}{l}\text{Nucleus}\hfill \end{array}\hfill & \begin{array}{l}\text{Well defined nucleus is absent }\\ \text{in prokaryotes}\text{. The nucleus}\\ \text{ is present as nucleiod body}\text{.}\end{array}\hfill & \begin{array}{l}\text{They contain well }\\ \text{defined nucleus}\text{.}\end{array}\hfill \\ \text{Plasma membrane}\hfill & \begin{array}{l}\text{Only one plasma membrane }\\ \text{is present}\text{.}\end{array}\hfill & \begin{array}{l}\mathrm{They}containinternal\\ membranesystem.\end{array}\hfill \\ \text{Membrane bound organelles}\hfill & \begin{array}{l}\text{They do not possess any membrane }\\ \text{bound organelles}\text{.}\end{array}\hfill & \begin{array}{l}\text{Membrane bound }\\ \text{organelles }\\ \text{like mitochondria,}\\ \text{endoplasmic reticulum,}\\ \text{ ribosome, lysosomes }\\ \text{and others are present}\\ \text{ in eukaryotes}\text{.}\end{array}\hfill \\ \text{Size}\hfill & \begin{array}{l}\text{They have smaller size than }\\ \text{eukaryotes}\text{.}\end{array}\hfill & \begin{array}{l}\begin{array}{l}\text{Eukaryotes are}\\ \text{ larger in size}\text{. }\\ \text{Yeast is the smallest}\\ \text{ eukaryotic cell that}\\ \text{ is much larger than }\\ \text{the prokaryotic cells}\text{.}\end{array}\hfill \end{array}\hfill \\ \text{Organization of cells}\hfill & \begin{array}{l}\text{They are single-celled}\\ \text{ organisms}\end{array}\hfill & \begin{array}{l}\text{They can be single celled}\\ \text{ organisms like yeast or }\\ \text{multi-celled organisms}\\ \text{ like hydra, echinoderms,}\\ \text{ mammals and other }\\ \text{organisms}\text{.}\end{array}\hfill \end{array}$

Conclusion

Prokaryotes and eukaryotes differ on the basis of cell size, level of organization, presence of membrane-bound organelles, organization of nucleus, and presence of the internal membrane system.