Anew hormone, hormone x, is found to regulate the blood concentration of hormone y via a negative feedback loop. when blood concentrations of hormone y increase,
a. hormone x secretions will decrease due to the negative feedback. b. hormone x secretions will increase due to the negative feedback. c. hormone x will be in its normal range. d. hormone x will decrease due to positive feedback.

Which of the following typically characterizes a tropical rainforests

The distant ancestors of tigers may have had bodies without stripes. use the theory of natural selection to explain how tigers may have evolved to have stripes.

This is a typical grassland food web. it is also a small picture of an important cycle on earth: the carbon cycle. describe how the carbon gets into this food web. a) bacteria and fungi, the decomposers, recycle carbon from dead organisms. b) carbon is found in the grass and is passed from one level to the next in this food web. eliminate c) all living things give off carbon dioxide as a by-product of respiration and it is released into the atmosphere. d) plants use carbon dioxide as a reactant in photosynthesis, to make usable chemical energy in the form of a sugar.