Your book cites 3 signals necessary for CD4 T cells’ activation and differentiation. What are they? 

Echinoderm means

In what form do autotrophs pass carbon to heterotrophs?

Which body plan represents an acoelomate?

True or False?  Evaporation can occur over land and over bodies of water?

While wading in the ocean, you look down into the water and notice an umbrella-shaped, translucent animal. It swims by pulsing its body, and long tentacles trail behind it. One of them brushes your leg. Ouch! You feel a burning sensation where it touched you. The burning sensation, or sting, was caused when the _________ brushed your skin.

Which of the following best describes this organism?  

The organism indicated is  

All seaweeds are

Which of the following structures does this organism possess?