Within the human body, bacteria exist in greatest numbers in the _____, with most of these bacteria having a ______ relationship with their human host.

a. lungs; commensal

b. feet; antagonistic

c. digestive tract; mutualistic

d. digestive tract; pathogenic

e. kidneys; mutualistic

Archaea (select all that apply):

a. are single-celled prokaryotes.

b. are restricted to marine environments.

c. are superficially similar to bacteria.

d. are restricted to extreme environments.

e. constitute one of the three domains of life.

Protists were the first life-forms to (select all that apply);

a. appear on Earth.

b. reproduce through binary fission.

c. reproduce sexually.

d. evolve following bacteria and archaea.

e. exhibit true multicellularity.

Phytoplankton are important because they (select all that apply):

a. produce antibiotics.

b. produce oxygen.

c. sit at the base of terrestrial food chains.

d. sit at the base of aquatic food chains.

e. fight viruses.

Human beings appear to have evolved into their present anatomical form in _______.

Were modern human beings the first hominin species to reach Europe and Asia?

The “Hobbit” people, Homo floresiensis, are thought to have survived until as recently as _______ years ago on an island that is part of present-day _______.

The two most important features in distinguishing hominins from apes are _______ walking and _______ structure.

The “Lucy” hominin was like modern human beings in that she was _______. but unlike them with respect to _______ size.

Lucy shows us that hominin features evolved in a _______ pattern, which is to say that different features evolved at different points in time and in different species.

The taxonomic group of human-like primates, the hominins, is thought to have originated between _______ years ago with a common primate ancestor who gave rise to both the hominin and _______ evolutionary lines.