steady state of an ecosystem where all organisms are in balance with their environment and each other

hormone produced by the kidneys to stimulate red blood cell production in the bone marrow

tubular organ that connects the mouth to the stomach

nutrient that cannot be synthesized by the body; it must be obtained from food

torpor in response to extremely high temperatures and low water availability

reproductive hormone in females that assists in endometrial regrowth, ovulation, and calcium absorption

a group of steroid hormones, including estradiol and several others, that are produced by the ovaries and elicit secondary sex characteristics in females as well as control the maturation of the ova

biomes where a source of fresh water, such as a river, meets the ocean

biological study of animal behavior

volatile plant hormone that is associated with fruit ripening, flower wilting, and leaf fall

animal with a body cavity completely lined with mesodermal tissue

organism with cells that have nuclei and membrane-bound organelles

proposal that prokaryotes evolved from eukaryotes

cell that has a membrane-bound nucleus and several other membrane-bound compartments or sacs

protein that binds first to an mRNA to initiate translation