| 1) Which two structures play direct roles in permitting bacteria to adhere to each other, or to other surfaces?|
A) 1 and 3
B) 3 and 4
C) 3 and 5
D) 1 and 2
E) 2 and 3
|A) 1 and 3|
| 2) Which of the following is a structure that permits conjugation to occur?|
B) sex pilus
C) cell wall
|B) sex pilus|
| 3) Not present in all bacteria, this cell covering enables cells that possess it to resist the defenses of host organisms:|
C) sex pilus
D) cell wall
| 4) Which of the following requires ATP to function, and permits some species to respond to taxes (plural of taxis)?|
A) sex pilus
D) cell wall
|5) What's the difference between a prokaryotic cell and a eukaryotic one?||-Eukaryotic cells have a true nucleus, bound by a double membrane. Prokaryotic cells have no nucleus.|
-Eukaryotic DNA is linear; prokaryotic DNA is circular (it has no ends)
-Eukaryotic DNA is complexed with proteins called "histones," and is organized into chromosomes; prokaryotic DNA is "naked," meaning that it has no histones associated with it, and it is not formed into chromosomes
-Both cell types have many, many ribosomes, but the ribosomes of the eukaryotic cells are larger and more complex than those of the prokaryotic cell
-The cytoplasm of eukaryotic cells is filled with a large, complex collection of organelles, many of them enclosed in their own membranes; the prokaryotic cell contains no membrane-bound organelles which are independent of the plasma membrane
-Eukaryotic cells are the largest cells, while Prokaryotic cells are smaller than Eukaryotic cells.
|6) What's the difference between the cell wall of bacteria, archaea, plants and fungi?||Bacteria: contain peptidoglycan, a network of sugar polymers cross-linked by polypeptides |
Archaea: the wall is assembled from surface-layer proteins, which form an S-layer. An S-layer is a rigid array of protein molecules that cover the outside of the cell (like chain mail.) This layer provides both chemical and physical protection, and can prevent macromolecules from contacting the cell membrane. Unlike bacteria, most archaea lack peptidoglycan in their cell walls.
Plants: composed of cellulose and hemicellulose, pectin and in many cases lignin, and secreted by the protoplast on the outside of the cell membrane. This contrasts with the cell walls of fungi (which are made of chitin), and of bacteria, which are made of peptidoglycan.
Fungi: contain chitin, unlike the cell walls of plants, which contain cellulose.