Is the following an example of a. Negative feedback loop b. Positive feedback loop Hydrochloric acid and pepsin are enzymes secreted by cells in your stomach to digest proteins. The presence of partially digested protein in the stomach triggers the secretion of more hydrochloric acid and pepsin. Thus, once digestion begins, it becomes a self-accelerating process. Is the following an example of a. Negative feedback loop b. Positive feedback loop

 This is a positive feedback loop.

Explanation:

The protein digestion in the body is an example of the positive feedback. The gastric secretions is stimulated chiefly by the action of three chemicals.

These chemicals are acetylcholine, histamin and gastrin. These chemicals stimulate the parietal cells to secrete HCL and intrinsic factors.

The chief cells secrete pepsinogen in response to the gastrin and ACh. As the dietary proteins are digested, it breaks down the amino acids and peptides.

This stimulates the G cells of the stomach to secrete more gastrin. This is how the positive feedback loop for the protein digestion works.

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.