Choose the correct answer.

Which phylum includes animals that lack tissues?

A. Cnidaria

B. Porifera

C. Platyhelminthes

D. Arthropoda

E. Chordata

What is an advantage of sexual reproduction?

Write a paragraph as if you are a molecule of ammonia that will be converted to uric acid and then to urea and excreted as urine. Start in the blood and finish as the urine leaves the body.

Which of these are greenhouse gases? Choose ALL that are correct. carbon dioxide nitrogen oxygen methane carbon monoxide water vapor

What part of the brain controls breathing and heart rate?

In scientific investigations, experimental results are checked by?

Natural Killer cells react in predictable ways. Put the following steps in order to describe the actions of an activated NK cell. A. Recognition and adhesion B. Section of perforins C. Lysis of the abnormal cell D. Realignment of Golgi apparatus

In the Hershey-Chase experiment, the material that entered cells upon infection by T2 virus was labeled with which radioactive isotope?

Compared to absolute dating, what is a disadvantage of relative dating? Fossils must be in undisturbed rock layers to determine age. Age, in years, cannot be determined for an individual fossil.

How many laces are on a shoe

Solve for x: one over five (5x + 12) = 18 A) 78/5 B) 102/5 C) 6 D) 30