Which of these best describes a hormone? O A. A chemical message with a specific target
O B. An enzyme delivered to a specific gland
O C. Any message carried by the bloodstream
D. A steroid carrying a message to a receptor cell

(select all the correct choose each statement that is scientific. - the opinions of randomly selected participants in a survey prove the idea that global temperatures are not increasing on earth. - the universe's average temperature and rate of expansion support the idea that it began as one super-dense and hot mass 13.8 billion years ago. - ocean tides are caused by the uneven gravitational pulls of the moon and sun on different parts of earth. - human life is more valuable than other forms of life on earth because humans are more intelligent than other organisms.

Explain why it’s important for scientists to study the sun. list at least two challenges researchers face when examining earth’s nearest star.

If the charge that enters each meter of the axon gets distributed uniformly along it. true or false