In the secondary structure of proteins, what type of bond dictates how the protein folds? A. Hydrogen bonds
B. Covalent bonds
C. Ionic bonds
D. Metallic bonds

What does it mean for a cell membrane to be selectively permable

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

15 ! come and answer! a(n) is the general term for an infectious disease that has spread across a city, region, or country.