Which one of these exhibits gill slits at some stage of its development?

A. all echinoderms

B. all mollusks

C. all cnidarians

D. all chordates

Describe how the body responds to different types of medicine.

What part of genes control a trait

Imagine five forest communities, each with one hundred individuals distributed among four different tree species (W, X, Y, and Z). Which forest community would be most diverse?

If a drug were found that blocked all calcium channels that are linked to G-protein coupled receptors, would it completely block the use of calcium as second messenger? Explain your answer.

Freud referred to a lingering focus of pleasure-seeking energies at an earlier psychosexual stage as

Which of the following scenarios describes an epistatic gene interaction?

An 1815 volcanic eruption in Indonesia was followed by a three-year famine around the world. How was the volcano linked to the famine? O A. The eruption's ash and gas significantly dimmed the sun. B.

In the general equation of photosynthesis, why is chlorophyll written over the arrow rather than on the left side of the equation'

How many years did the Precambrian Era span? 2.5 billion 5 million 5,000 none of the above

Explain why most quartz is useful?