Lecture 2- Prokaryotes Flashcards
A(n) _____ is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently.
Plasmid
What organism is thought to be the ancestor of chloroplasts?
Cyanobacteria
Which domain do methanogens belong to?
Archaea
Which type of horizontal gene transfer involves the incorporation of foreign DNA as plasmids or into bacterial genome?
Transformation
_____ is a carbohydrate polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of most bacteria, forming the cell wall
Peptidoglycan
What is the difference between positive and negative taxis?
Positive taxis is movement towards a stimulus, whereas negative taxis is movement away from a stimulus
What color do gram-positive bacteria appear after gram staining?
Purple
How do prokaryotes reproduce?
Binary fission
True or False: Both prokaryotic and eukaryotic flagella are covered by a plasma membrane
False; only eukaryotic flagella are covered by plasma membrane
What color do gram-negative bacteria appear after gram staining?
Pink
What is the difference between vertical gene transfer and horizontal gene transfer?
Vertical gene transfer is the transfer of genetic material from parent to offspring, whereas horizontal gene transfer is the transfer of genetic material NOT from parent to offspring
______ is the process by which foreign DNA is introduced into a cell by a virus
Transduction
True or False: Cell walls of plant cells contain peptidoglycan
False; peptidoglycan is exclusive to bacteria
What is the most recent ancestor of the mitochondria?
Alpha proteobacteria
What are halophiles?
Extremophiles that thrive in high salt concentrations
Why do gram-positive bacteria appear purple after gram staining?
Due to the thick peptidoglycan layer in their cell wall
______ is the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surroundings through the cell membrane(s)
Transformation
A(n) ____ _____ is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation or anaerobic respiration if oxygen is absent
Facultative anaerobe
What are thermophiles?
Extremophiles that thrive in high temperatures
What is the outer membrane of gram-negative bacteria composed of?
Lipopolysaccharides (LPS) and a thin peptidoglycan layer