AP BIOLOGY

EVOLUTION

THE ORIGIN OF LIFE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Mitochondria and chloroplasts are thought to be ____ cells engulfed by a larger one.
A
plants
B
prokaryotic
C
eikaryotic
D
viruses
Explanation: 

Detailed explanation-1: -Mitochondria and chloroplasts likely evolved from engulfed prokaryotes that once lived as independent organisms. At some point, a eukaryotic cell engulfed an aerobic prokaryote, which then formed an endosymbiotic relationship with the host eukaryote, gradually developing into a mitochondrion.

Detailed explanation-2: -The theory of how mitochondria, chloroplasts and other membrane-bound organelles in eukaryotic cell likely arose from a symbiosis between aerobic prokaryotes and host anaerobic eukaryotic ancestors. Developed by Lynn Margulis.

Detailed explanation-3: -Although both organelles are found in eukaryotic cells, both mitochondria and chloroplast are often found in prokaryotic cells. These prokaryotic cell characteristics include: enclosed double membrane, circular DNA, and bacteria-like ribosomes.

Detailed explanation-4: -Mitochondria and chloroplasts are the same size as prokaryotic cells and divide by binary fission. Mitochondria and chloroplasts have their own DNA which is circular, not linear. Mitochondria and chloroplasts have their own ribosomes which have 30S and 50S subunits, not 40S and 60S.

Detailed explanation-5: -Mitochondria and chloroplasts are much larger than prokaryotic cells.

There is 1 question to complete.