NURSING EXAM QUESTIONS
MICROBIOLOGY
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Variable numbers of protein-encoding genes
|
|
|
Large stretches of AT-rich DNA
|
|
|
rRNA genes most closely related to Bacteria
|
|
|
Linear and circular genome structure in different organisms
|
Detailed explanation-1: -Most important are the many striking similarities between prokaryotes (like bacteria) and mitochondria: Membranes-Mitochondria have their own cell membranes, just like a prokaryotic cell does. DNA-Each mitochondrion has its own circular DNA genome, like a bacteria’s genome, but much smaller.
Detailed explanation-2: -The serial endosymbiosis theory, currently the most popular hypothesis to explain the origin of mitochondria, postulates the capture of an alpha-proteobacterial endosymbiont by a nucleus-containing eukaryotic host resembling extant amitochondriate protists.
Detailed explanation-3: -The mitochondrial genome contains 37 genes that encode 13 proteins, 22 tRNAs, and 2 rRNAs. The 13 mitochondrial gene-encoded proteins all instruct cells to produce protein subunits of the enzyme complexes of the oxidative phosphorylation system, which enables mitochondria to act as the powerhouses of our cells.