Hey there!
The purpose of guard cells is to control the opening and closing of the Stomata, keeping it the correct width, or size.
Therefore, your correct answer would be Option 3, control the size of the Stomata.
Hope this helps!
Explanation:
Hormone production and release are primarily controlled by negative feedback. In negative feedback systems, a stimulus causes the release of a substance whose effects then inhibit further release. In this way, the concentration of hormones in blood is maintained within a narrow range.
One advantage of genetic engineering is the production of valuable proteins: recombinant DNA made possible the use of bacteria to produce proteins of medical importance such as genetically engineered human insulin which is of great importance.
Another advantage is the production of vaccines. Vaccines produced by genetic engineering offer an advantage that the microbial strains from which proteins are extracted do not contain complete viruses and thus there is no risk of accidental inoculation with live virus.
