Which structure represents the body's first line of defense against infection? A. Thymus
B. Skin
C. Bone marrow
D. Tonsils

Question 3(multiple choice worth 4 points) (02.04 lc) which best describes the function of chloroplast? allows certa molecules to enter and exit the cell makes food during photosynthesis detoxifies waste products o packages proteins into vesicles

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.

Why is it incorrect to say that mitochondria function only as energy factories with cell