Question

According to the phagotrophic (predatory) hypothesis of Thomas Cavalier-Smith, the correct sequence for the origin of the earliest eukaryotic cell structures was:

A. the cytoskeleton originated first, the nucleus second, and the protomitochondrion last

B. the protomitochondrion originated first, the nucleus second, and the cytoskeleton last

C. the cytoskeleton originated first, the protomitochondrion second, and the nucleus last

D. the nucleus originated first, the protomitochondrion second, and the cytoskeleton last

E. the protomitochondrion originated first, the cytoskeleton second, and the nucleus last

Answer 1

D. the nucleus orginated first, the protomitochondrion second and   the cytoskeketon last.

The first eukaryote may have orginated from an ancestral prokaryote that had undergone membrane prolifration,compartmentalization of cellular function into nucleus and ER.

In a first endosymbiotic event, the ancestral eukaryote consumed aerobic bacteria that evolved into mitochondria.

In a second endosymbiotic event,the early eukaryote consumed photosynthetic bacteria that evolved into chloroplast and cytoskeleton.