I'm the part of the digestive tract that absorbs only water.
What is the large intestine?
I have lots of surface area for gas exchange in a clam.
What are gills?

I'm made of only proteins and DNA.
What are viruses? What is a bacteriophage?
I help the cell maintain its internal environment, as in homeostasis.
What is a cell membrane?
I'm a single-celled swimmer with a nucleus in your pond water.
What is an "animal-like" protist?
Urine has this in it.

What is urea? What is water? What is salt? What is H+? Basically, what is anything EXCEPT big molecules like ______________?

I have a 4 chamber heart, one-way lungs, amniotic eggs, and am a endotherm.
What is a bird?
I'm a eukaryote cell and this helps me organize 'cause I'm HUGE!
What is compartmentalization or having organelles?
Oops, forgot to drink milk. No worries. I'll get calcium from this in my body.
What is bone? What is parathyroid hormone?
I'm a "fun guy" and this bigger part of me stays in the dirt.
What is mycelium?
Photosynthesis needs water and this molecule - which it "fixes".
What is carbon dioxide?
I have two spirals that twist to the right and can be found in a nucleus or in the nucleoid.
What is DNA?
Love using this for bacterial infections, but I better not see you use it for a viral infection!
What are antibiotics?

I'm the random portion of natural selection
What is a mutation (to generate variation)?
I'm the shortest of plants, with a little root that goes sideways, and I don't have xylem or phloem, sigh...
What is a moss?
I'm a red blood cell and, sadly, I burst in this kind of environment.
What is hypotonic?
I'm little holes where water evaporates and CO2 enters.
What are stomata?
I'm great for seed dispersal.
What is a fruit?
Drs. Hardy and Weinberg wanted big populations to avoid this mechanism of microevolution.
What is genetic drift (bottleneck or founder effect)?
The variable that is measured in an experiment.
What is a dependent variable.
I'm the process that moves water from the roots to the atmosphere through a tree....
What is inspire? No! Respire? No! What is TRANSPIRE!!
I'm the product of two meiotic events and am 1 in 8 million possibilities for each.
Who am I???
String me together with others to make a protein.
What are amino acids?
I'm a Galapagos finch who is very picky about who I mate with - my mate must have the same beak size and love my song.

What is they have a behavioral barrier (different mating songs), habitat barrier (different islands), etc? Any answer that has a barrier to breeding/reproduction. What is speciation?
I'm dead, but I can move water
What is a xylem?