Josh notices that the frog he is dissecting has many different types of tissues and cells. the cells are different due to
a) different gene expression.
b) different environmental factors.
c) different dna in the cells of the frog.
d) different rna in the cells of the frog.

“in 1492 columbus sailed the ocean blue” is an example of: a)explicit memory b) procedural memory c) semantic memory d)episodic memory

How do living things obtain phosphorus

Juan and carol were studying invertebrates in biology. they knew that segmented or earth worms preferred a dark, moist habitat. during this lab, they would be investigating the responses of organisms called planaria or dugesia tigrina. these were simple flatworms that still had a one-way digestive system and a very simple nervous system. juan and carol placed the planaria in a petri dish containing cool, distilled water that was partially covered with black paper. they shined a light on the dish. next, they removed the paper and placed a small amount of chicken liver at one end of the dish. they added a few large salt crystals to the water. finally, they added drops of hot water to the cool water in the petri dish. their results can be seen in the data table. according to their experiment, all but one conclusion is valid.