Answer:
Nucleus
Explanation:
Prokaryotes are the organism that came earlier than eukaryotes on this earth. These prokaryotes do not have a nucleus and other membrane-bound organelles like chloroplast, mitochondria, Golgi apparatus, endoplasmic reticulum, etc.
So as prokaryotes lack membrane-bound organelle their genetic material is not enclosed in the nucleus therefore their genetic material remains in the cytoplasm of the cell while eukaryotes have membrane-bound nucleus in which their genetic material are present.
So the nucleus is the major organelle that prokaryotes are missing that eukaryotes have.
True
Chloroplasts are organelles that are responsible for the photosynthetic functioning of an organism.Photosynthesis is the process by which an organism uses the photons to produce energy. These organisms uses the sun, together with the acquired resource of water and carbon dioxide to create sugar and process into energy.
B .............................................................................
Answer:
The options A, B, and D are all valid.
Explanation:
- The reason is that some proteins require molecular chaperones if they are to fold properly within the environment of the cell. In the absence of chaperones, a partially folded polypeptide chain has exposed amino acids that can form non-covalent bonds with other regions of the protein itself and with other proteins, thus causing nonspecific aggregation of proteins.
- The option A) is correct because the protein you are expressing in bacteria is being made in large quantities, it is possible that there are not enough chaperone molecules in the bacterium to fold the protein. Expressing the protein at lower levels might increase the amount of properly folded protein.
- The option B) is correct as urea should solubilize the protein and completely unfold it. Removing the urea slowly and gradually often allows the protein to refold. Presumably, under less crowded conditions, the protein should be able to refold into its proper conformation.
- The option C) is not correct as treating the aggregate with a protease, which cleaves peptide bonds, will probably solubilize the protein by trimming it into pieces that do not interact as strongly with one another; however, chopping up the protein will also destroy its enzymatic activity.
- The option D) is correct because overexpressing chaperone proteins might increase the amount of properly folded protein.
- The option E) is not correct as heating can lead to the partial denaturation and aggregation of proteins to form a solid gelatinous mass, as when cooking an egg white, and rarely helps solubilize proteins.
