Tissue cultures (samples of cancer cells) are taken from cancer patients, and the cells are then grown in a laboratory. What is the purpose of growing cancer cells in a laboratory? to test medicinal treatments before giving them to patients
to replace cancer cells with healthy cells
to provide evidence of cancer cells in the patient
to stop the cancer from growing in the patient

According to the law of conservation of energy, energy can neither be created nor destroyed. if this is true, why is there less energy in the top of the energy pyramid than there is in the bottom of the energy pyramid?

Ryan rears sheep for their wool. recently the quantity of wool that ryan gets has diminished. this is because the new sheep are not that wooly. ryan should add which nutrient to their feed so that the sheep becomes more wooly? a. cornb. ironc. cottonseedd. vitamin a

What sentence best supports the statement that hormones are involved in the regulation of homeostasis? a. the hormone erythropoeitin increases the production of red blood cells when oxygen levels are low. b. the hormone oxytocin promotes labor contractions of the uterus during childbirth. c. the hormone melatonin induces sleep and its production is slowed by exposure to light. d. the hormone cortisol suppresses the immune system and is produced when the body is under stress.