The answer is B. a nucleus.
Prokaryotic cells do not have a nucleus. They have ribosomes, a cell membrane, a cell wall, and DNA, but lack a nucleus. Prokaryotes also don't have mitochondria or chloroplasts and generally lack organelles.
Change the pH and the enzyme<span> stops working. Increasing the temperature to 60°C will cause a permanent change to the shape of the active site. This is why </span>enzymes<span> stop working when they are heated. We say they have become </span>denatured<span>.</span>
Answer:
In solids, precipitation occurs if the concentration of one solid is above the solubility limit in the host solid, due to rapid quenching or ion implantation, and the temperature is high enough that diffusion can lead to segregation into precipitates.
Explanation: