Where do plants get the nitrogen they need to create amino acids and DNA? A. Plants get their nitrogen from nitrogen gas (N2), which moves into leaves through holes called stomata.

B. Plants take up nitrates (NO3-) from the soil and convert them into ammonia (NH3).

C. Nitrogen-fixing bacteria convert nitrogen gas (N2) into ammonia (NH3), and plants take up some of the ammonia (NH3) through their roots.

D. Both B and C are correct.

E. A, B, and C are all correct.

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.

This class has taught you that the use of science and medicine in practical ways has become an international endeavor. one of the greatest examples of an international science accomplishment is which allows the profiling of human dna, useful not only to science but also medicine. a) forensic science b) the fbi c) the human genome project d) bioterrorism

Use the above pedigree for questions 1,2, and 3 1. what kind of genetic disorder is represented in the pedigree? a. recessive b. dominate refer to the pedigree in question 1. 2. is the mutated gene in this disorder located on a sex chromosome (x or y) or an autosome? a. sex chromosome b. autosome refer to the pedigree in question 1. 3. which generation has individuals that you are certain are heterozygous for the mutated gene? a. generation 1 b. generation 2 c. generation 3