Chapter 3, Problem S1.2BYB

Summary Introduction

To review:

The differences between prokaryotic and eukaryotic cells.

Introduction:

Among the entire group of organisms, the distinction between prokaryotic and eukaryotic organisms is considered to be the most important. It is assumed that prokaryotes were the only form of life on Earth for millions of the years until the evolution of complicated eukaryotic cells took place.

Explanation of Solution

Eukaryotic cells comprise of membrane-bound organelles like the nucleus, while prokaryotic cells do not contain any membrane-bound organelles. Apart from this, the number of chromosomes present in a eukaryotic cell is greater in the number than the prokaryotic cells which is actually a plasmid. Eukaryotic cells are usually multicellular while the prokaryotic cells are unicellular. However, some types of cyanobacteria are found to be multicellular as an exception.

Eukaryotic cells contain a true membrane-bound nucleus while prokaryotic cells do not. The examples of eukaryotic cells include animals and plants, while the examples of prokaryotic cells include bacteria and archaea. The genetic recombination in eukaryotic cells occurs by meiosis and fusion of the gametes, while genetic recombination in prokaryotic cells occurs by the partial, unidirectional transfer of DNA.

Furthermore, eukaryotic cells include structures like lysosomes, peroxisomes, microtubules, endoplasmic reticulum, mitochondria, and cytoskeleton which are absent in prokaryotic cells. The prokaryotic cells may have cytoskeleton and microtubules in very rare situations.

The cell wall of prokaryotes is made of peptidoglycan, whereas eukaryotic cells do not have a cell wall. Prokaryotes are smaller than eukaryotic cells. Additionally, prokaryotes have a high metabolic rate, a higher growth rate and shorter generation time in comparison to eukaryotic cells. Prokaryotes have compact genomes.

Conclusion

Hence, it can be concluded that prokaryotic and eukaryotic cells differ greatly in their cell and nuclear composition, types of structures present, genomic recombination, metabolic rate, etc.