The energy input into an ecosystem can come from a. sunlight
b. chemical compounds
C. soil
d. A and B

Which of the following is the most likely result of converting forestland to urban development? a.the amount of land available for lumber production decreases. b.fewer trees are needed because cities are made mainly of concrete. c.people discover more efficient ways to grow trees. d. the price of lumber goes down.

Imagine you are introducing the lac operan and the trp operon to students who have never learned about it before. complete the table to compare the similarities and differences between the two operons

Ivan is looking at a cross section of a stem taken from a vascular plant. he sees two different types of vascular tissue: the xylem, which is closer to the center of the stem, and the phloem, located around the xylem, closer to the outside of the stem. how do these two structures work together in a living plant?