What system is one in which hormones are fed back to inhibit the original signal

*will mark brainliest to first correct answer* photosynthesis led to increasing levels during the later proterozoic eon? a. oxygen b. water c. carbon dioxide d. none of the above

Can happen anywhere along the spine if the neural tube does not close all the way. the backbone that protects the spinal cord does not form and close as it should. this often results in damage to the spinal cord and nerves. a) cleft palate b) spina bifida c) encephalocele d) down's syndrome

Explain how negative feedback caused the changes in plasma glucagon concentration observed during the experiment.