Structures external to the bacterial cell wall that is used for motility (movement) by chemotaxis:

Okay, everyone. Structures external to the bacterial cell wall that is used for motility or movement by chemotaxis is which of these answers? Okay. So we know that chemotaxis is the process that bacterial cells can take when they move towards a chemical attractant in their environment and or away from a chemical repellent in their environment. This is very similar to phototaxis where the bacterial cell can move towards or away from a light source. But, basically, the thing to understand here is that these bacterial cells are moving through their environment towards something or away from something. And, how do they do that? What structure do they use? They're going to use their flagella. The correct answer here is answer choice c. Flagella are those whip or tail like structures that allow bacterial cells to swim long distances through their environment. And, this structure is gonna be used by chemotaxis and phototaxis. The only other answer here that could be utilized for locomotion would be pili, but they're not really used for extremely long distances or swimming through their environment, such as flagella. So, this is not the correct answer. All these other answers here, endospores, capsules, and ribosomes are not utilized for movement and are actually Remember that endospores are dormant cells. Capsules are an outer layer of bacteria not used for movement, and ribosomes are gonna be used for protein production inside the cell, they're not gonna be used for movement, so none of these other answers are correct. These structures external to the bacterial cell wall used for movement in chemotaxis and phototaxis are the flagella. Okay, everyone. Let's move on to our next video.