B
The chloroplasts of all of the following are thought to be derived from ancestral red algae, except those of
A) golden algae.
B) diatoms.
C) dinoflagellates.
D) green algae.
E) brown algae.
What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth?
1. origin of mitochondria
2. origin of multicellular eukaryotes
3. origin of chloroplasts
4. origin of cyanobacteria
5. origin of fungal-plant symbioses
A) 4, 3, 2, 1, 5
B) 4, 1, 2, 3, 5
C) 4, 1, 3, 2, 5
D) 4, 3, 1, 5, 2
E) 4, 3, 1, 2, 5
Which of these observations gives the most support to the endosymbiotic theory for the origin of eukaryotic cells?
A) the existence of structural and molecular differences between the plasma membranes of prokaryotes and the internal membranes of mitochondria and chloroplasts
B) the similarity in size between the cytosolic ribosomes of prokaryotes and the ribosomes within mitochondria and chloroplasts
C) the size disparity between most prokaryotic cells and most eukaryotic cells
D) the observation that some eukaryotic cells lack mitochondria