PLEASE HELP!! IM STRUGGLING LOL All chordates have:
A. A single, dorsal, tubular, nerve cord
B. All of these
C. A dorsal heart
D. pharyngeal gill slits used for respiration

Although there are a limited number of amino acids many different types of proteins exist because..

My question says on my assignment. read the following scenarios and decide which of the properties of life are being described. the first one is. katherine stopped on the way to school to grab some donuts. 2. because a dog cannot sweat, it has to pant in order to stay cool. 3. an elephant trun had no bone but 4,000 muscles. i have no idea what i am supposed to anwer. i can't find the answer in my notes or book that i can understand anyway

The two tubes contain bromothymol blue. after 24 hours, what will the color of the water be in tube b? a. green (it won't change) b. yellow c. blue d. colorless (clear)