What do proteins, nucleic acids, and carbohydrates all have in common? A. They all use peptide bonds to form macromolecules.
B. They all contain the instructions for building organisms.
C. They are all formed from the same elements.
D. They are all made of chains of amino acids.

When analyzing tree rings, what do scientists assume a thin ring indicates?

Cells destroy body cells infected by a virus or bacteria.

True or false: (a) the strings of little red dots represent carbohydrates. (b) the model is called a bilayer because there are two main types of molecules present, lipids and proteins. (c) the many black lines represent amino acid tails. (d) this model shows membrane transport. (e) the blue ovals are hydrophobic. (f) the blue ovals represent phospholipid heads.