AP Biology · Topic 2.11
Origins of Cell Compartmentalization Practice
Part of Cell Structure and Function.(ENE-1.K)
Practice questions
3
Sample questions
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Sample 1difficulty 3/5
Evidence supporting the endosymbiotic origin of mitochondria includes all of the following <strong>except</strong>
- A
Mitochondria have their own circular DNA
- B
Mitochondrial ribosomes resemble bacterial ribosomes
- Ccheck_circle
Mitochondria contain a nucleus
- D
Mitochondria have double membranes
Why
Mitochondria do not have a nucleus. The other three are classic pieces of evidence for engulfed-bacteria ancestry.
- A
Sample 2difficulty 4/5
Evidence for the endosymbiotic origin of mitochondria includes
- A
Synthesis of all their proteins by free cytosolic ribosomes
- B
Their absence in all anaerobic eukaryotes
- C
Their identical genetic code with the host nucleus
- Dcheck_circle
Circular DNA, 70S ribosomes, double membrane, and binary-fission replication
Why
Margulis's serial endosymbiosis: mitochondria show prokaryote- like features (circular genome, 70S ribosomes, double membrane, fission) — descended from a captured α-proteobacterium.
- A
Sample 3difficulty 4/5
Mitochondria contain their own circular DNA, divide by binary fission, are surrounded by a double membrane, and have ribosomes more like bacterial than eukaryotic ribosomes. These observations were used to propose the endosymbiotic theory.
Which observation provides the STRONGEST support for the endosymbiotic origin of mitochondria?
- A
Mitochondria are smaller than the nucleus
- Bcheck_circle
Mitochondria contain their own circular DNA distinct from nuclear DNA
- C
Mitochondria contain proteins encoded by nuclear DNA
- D
Mitochondria can be removed by centrifugation
Why
Possessing their own circular bacterial-style genome and ribosomes that resemble those of bacteria most directly supports a free-living bacterial ancestry.
- A