53) Based on cladistics, which eukaryotic kingdom is polyphyletic and, therefore, unacceptable?
A) Plantae
B) Fungi
C) Animalia
D) Protista
54) Which eukaryotic kingdom includes members that are the result of endosymbioses that
included an ancient aerobic bacterium and an ancient cyanobacterium?
A) Plantae
B) Fungi
C) Animalia
D) Protista
55) A large proportion of archaeans are extremophiles, so called because they inhabit extreme
environments with high acidity, salinity, and/or temperature. Such environments are thought to
have been much more common on the primitive Earth. Thus, modern extremophiles survive only
in places that their ancestors became adapted to long ago. Which of the following is,
consequently, a valid statement about modern extremophiles, assuming that their habitats have
remained relatively unchanged?
A) Among themselves, they should share relatively few ancestral traits, especially those that
enabled ancestral forms to adapt to extreme conditions.
B) On a phylogenetic tree whose branch lengths are proportional to the amount of genetic
change, the branches of the extremophiles should be shorter than the non-extremophilic
archaeans.
C) They should contain genes that originated in eukaryotes that are the hosts for numerous
species of bacteria.
D) They should currently be undergoing a high level of horizontal gene transfer with non-
extremophilic archaeans.