Celery stalks that are immersed in fresh water for several hours become stiff. Similar stalks left in a 0.15 M salt solution become limp. From this, we can deduce that the fresh water ________.

Cell A has half as much DNA as cells B, C, and D in a mitotically active tissue. Cell A is most likely in

Use the following map of four genes on a chromosome to answer the question. Between which two genes would you expect the highest frequency of recombination? 

Cell A has half as much DNA as cells B, C, and D in a mitotically active tissue. Cell A is most likely in

Energy released by the electron transport chain is used to pump H+ ions into which location in eukaryotic cells?

Besides the ability of some cancer cells to over proliferate, which of the following situations might logically result in a tumor?

When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by _____. 

When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by _____. 

Density-dependent inhibition is explained by which of the following processes?

During which of the following processes does independent assortment of chromosomes occur?