Answer:
Fossil record, history of life as documented by fossils, the remains or imprints of organisms from earlier geological periods preserved in sedimentary rock. Their ages can be established by comparing the fossils in each layer.
One reason could be that they do not have most of the seven characteristics of life (reproduction, homeostasis, heredity, response to the environment, growth, cellular organization, and metabolism.)
Answer:
C. Pepsinogen is the active form of pepsin.
Explanation:
Pepsin is a gastric protease belonging to the aspartic proteinase family which breaks down polypeptide chains into smaller peptides by hydrolyzing peptide bonds. Pepsin is found in the gastric juice where it digests proteins from foods together with other digestive enzymes and hydrochloric acid. Moreover, pepsinogen is a precursor of pepsin which is secreted by the gastric chief cells of the human stomach and then is converted into pepsin (its active form) by hydrochloric acid.
