Which of the following is caused by the modification of density–independent factors? a. parasitic wasps invade cocoons, killing many caterpillars. b. periodic drought causes an abrupt decrease in vegetation. c. organisms compete for food, water, and other resources.

What is thought to have caused the mass extinction at the end of the cretaceous period?

2. how does the miller-urey experiment fall short of demonstrating that life can arise from inorganic molecules? explain. a. it doesn't show a leap between a collection of amino acids and a single-celled organism. b. it recreates the conditions that existed at the earth's beginning, but no molecules form as a result. c. it doesn't provide evidence of the formation of amino acids. d. it doesn't show how multicellular organisms developed from unicellular organisms

Other than earth, is also known to have magnetic pole reversal? a: venus b: mars c: earths moon d: the sun