Answer: Rosalind Franklin discovered the density of DNA and, more importantly, established that the molecule existed in a helical conformation. Her work to make clearer X-ray patterns of DNA molecules laid the foundation for James Watson and Francis Crick's suggestion that DNA is a double-helix polymer in 1953.
Explanation:
Answer: 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.
Answer:
Among the oldest methods of preservation are drying, refrigeration, and fermentation. Modern methods include canning, pasteurization, freezing, irradiation, and the addition of chemicals.
Explanation:
Answer:
C. development of vascular tissue for bulk flow
Explanation:
