What kind of bond exists between two amino acid in polypeptide

Aperson with age is more likely to catch diseases that healthy people usually don’t catch.what are these infections called?

If the dimensions of a cube-shaped cell with a length,height, and width of 1 micrometer were to double, what would be the cell's new ratio of surface area to volume? a.3 to 1 b.4 to 3 c.1 to 2 d1 to 6

What would most likely happen to a unicellular organism if it was exposed to a hypotonic solution for an extended period of time?