involved! In a comparison between Earth's biomes, it was noted that the desert and the tundra are similar in the fact that they both A)only receive less than 60 cm of rain annually.
B)support the fewest animal and plant species per square acre.
C)have the lowest annual precipitation and the highest temperatures.
D)have a mean annual temperature that rarely exceeds 20oC.

Which class of molecules contains the amino group, nh2 (a) sugars (b) water (c) proteins (d) hydrocarbons

What are antigens and antibodies? how are they involved in the body’s response to incompatible blood?

Which of the following best describes the purpose of the parathyroid hormone? a. it decreases the blood calcium level and decreases blood phosphorus level. b. it decreases the blood calcium level and increases the blood phosphorus level. c. it increases the blood calcium level and increases blood phosphorus level. d. it increases the blood calcium level and decreases blood phosphorus level.