Terrestrial vertebrates use the urea cycle to convert the ammonium ion to urea, which can then be excreted. In the production of urea, only one of the nitrogens in the product comes from an ammonium ion. What is the source of the other nitrogen in urea?

Sarah wants to know where in her garden chamomile would grow the best. she thinks chamomile will grow best in the corner of the garden that gets the most sunlight. to test her hypothesis, she decides to plant several groups of chamomile in her garden as an experiment. which of the following variables will sarah need to measure to know which group of plants grew best? a. the location of the plants b. the type of plants c. the height of the plants d. the amount of water she gives the plants

This image is an example of a(n) a) atom. b) compound. c) mixture. d) molecule.

Take a look at this dandelion. the yellow flower on the right is pollinated and the seeds on the left are transported by