Use the following choices to answer questions 9 and 10.
1. 9 + 2 flagella
2. 70s ribosome
3. fimbria
4. nucleus
5. peptidoglycan
6. plasma membrane


Which is (are) found only in prokaryotes?
a. 1,4,6
b. 3,5
c. 1,2
d. 4
e. 2,4,5

Verified step by step guidance

1. Identify the structures and components listed in the choices that are unique to prokaryotes.
2. Recall that prokaryotes are characterized by the absence of a nucleus and membrane-bound organelles.
3. Recognize that peptidoglycan is a major component of the cell wall in most bacteria, which are prokaryotes.
4. Understand that fimbriae are hair-like appendages found on the surface of many bacteria, aiding in attachment.
5. Match the identified prokaryotic structures (fimbriae and peptidoglycan) with the given answer choices.

Key Concepts

Prokaryotic Cell Structure

Prokaryotic cells are characterized by their lack of a true nucleus and membrane-bound organelles. Instead, their genetic material is located in a nucleoid region. Key structures include the plasma membrane, cell wall, and ribosomes, which differ from those in eukaryotic cells. Understanding these distinctions is crucial for identifying features unique to prokaryotes.

Peptidoglycan

Peptidoglycan is a polymer that forms a protective layer in the cell walls of bacteria, providing structural integrity and shape. It consists of sugars and amino acids, and is a defining characteristic of prokaryotic cells. Eukaryotic cells do not possess peptidoglycan, making it a key feature for distinguishing between these two cell types.

Ribosome Differences

Ribosomes are essential for protein synthesis, and their size differs between prokaryotes and eukaryotes. Prokaryotic ribosomes are classified as 70S, composed of 50S and 30S subunits, while eukaryotic ribosomes are 80S. This difference is significant in microbiology, as it can influence antibiotic targeting and the understanding of cellular functions.