Problem 12
True or false? Bipedalism is the defining trait of primates.
Problem 13
Homo erectus is a likely ancestor of \(H .\) sapiens and ________. a. Homo habilis b. australopiths c. the great apes d. Neanderthals
Problem 14
Match the organisms with the appropriate description. $$ \text {sponges} \quad \quad \text {a. most diverse vertebrates} $$ $$ \text {cnidarians} \quad \quad \text {b. no true tissues, no organs} $$ $$ \text {flatworms} \quad \quad \text {c.jointed exoskeleton} $$ $$ \text {roundworms} \quad \quad \text {d. mantle over body mass} $$ $$ \text {annelids} \quad \quad \text {e. segmented worms} $$ $$ \text {arthropods} \quad \quad \text {f. tube feet, spiny skin} $$ $$ \text {mollusks} \quad \quad \text {g. have specialized stinging cells} $$ $$ \text {echinoderms} \quad \quad \text {h. lay amniote eggs} $$ $$ \text {amphibians} \quad \quad \text {i. feed young secreted milk} $$ $$ \text {fishes} \quad \quad \text {j. unsegmented, molting worms} $$ $$ \text {birds} \quad \quad \text {k. first terrestrial tetrapods} $$ $$ \text {mammals} \quad \quad \text {l. tailless primates} $$ $$ \text {apes} \quad \quad \text {m. bilateral with a saclike gut} $$
Problem 15
Arrange the events in order, from most ancient to most recent. a. Cambrian explosion of diversity b. Origin of animals c. Tetrapods move onto the land d. Extinction of dinosaurs e. Homo erectus leaves Africa f. First jawed vertebrates evolve
