Why is it necessary to keep the frog's heart moistened with ringer's solution?

What hormonal preparations are used to raise the sperm count in infertility cases?

What is the answer to 4z^2-z^2?

What has to be true in order for organisms to be considered the same species?

Why is this a scientific question? "Do people perform better on exams when they wear their favorite color?" The question is not specific The question reflects an opinion The question can be tested by a systematic procedure.

The north pole of a bar magnet is moved close to the north pole of a second bar magnet. What prediction best describes how the first magnet responds when it is released?

During which stage of disease should an infected person be considered contagious

A scientist observed the boundrary between teo tectonic plates for a decade and finds that no new volcanoes have formed over the course of her investigation. Does this result suppor the theory of plate tectonic? Why or why not?

Do you think the channel on Mars was formed by flowing water or flowing lava

Does the presence of acid-fast organisms in a clinical specimen always suggest serious clinical disease? why or why not?

A plant using the sun the grow leaves, this is an example of A. photosynthesis. B. ecosystem. C. plant succession. D. evolution.