Which factor contributed least to the extinction of the passenger pigeon species?
A) laws that banned the hunting of passenger pigeons to sell in new markets
B) improved communication technology, which tracked the pigeon flocks
C) expansion of the railroads, which opened up new markets for selling pigeons
D) increased use of the passenger pigeons as a good source for humans

The intervention of extraterrestrials has been used to explain the bermuda triangle, a region of the atlantic ocean where ships and planes are frequently lost, leaving no evidence behind. how would this explanation best be characterized?

What sentence best supports the statement that hormones are involved in the regulation of homeostasis? a. the hormone erythropoeitin increases the production of red blood cells when oxygen levels are low. b. the hormone oxytocin promotes labor contractions of the uterus during childbirth. c. the hormone melatonin induces sleep and its production is slowed by exposure to light. d. the hormone cortisol suppresses the immune system and is produced when the body is under stress.

Food webs - transferring energy and matter from one level to another. here you see four food webs. one or more are incorrect. which food web(s) show the correct sequence of organisms, from start to top level consumer? a) a b) d c) c d) a and d