Which part of an amino acid is the only one that varies and is what defines its properties? a. the amino group b. the r group c. the carboxylic acid group d. the nitrogen base

Which statement is true about the cell theory? a) it is well-supported by evidence. b) it is unchangeable and permanent.

Discuss the functions of epithelial connective nerviud and muscular tissues

Which sentence best describes the relationship between chlorophyll and the chloroplast? a.)chlorophyll is a chemical found in a chloroplast. b.) chloroplast is a chemical found in a chlorophyll. c.) both chlorophyll and chloroplasts are found in animals. d.) both chlorophyll and chloroplasts make carbon dioxide.