The linking of amino acids is used to build which macromolecule?

You are looking at a sample from the top green layer of a colorful bacterial mat. Using phase contrast and fluorescence microscopy, you see evenly spaced cells in the middle of a filament that are slightly smaller than the others

The smaller cells are not fluorescent, indicating they lack photosystem II, but the rest of the filament is fluorescent. What type of filamentous bacteria are you most likely looking at? A) purple nonsulfur bacteria B) green sulfur bacteria C) Acidobacteria D) Cyanobacteria

The first part of the renal tubule is called the _____ and is specialized for _____

A. proximal convoluted tubule; reabsorption of electrolytes and other nutrients. B. loop of Henle; creation of a concentration gradient in the interstitial fluid C. distal convoluted tubule; secretion of additional wastes into the urine D. distal convoluted tubule; reabsorption of water E. collecting duct; reabsorption of water

Which of the following steps is the third step of the mating-type switch mechanism?

A. A 3' single-stranded overhang is created. B. The MAT locus is cleaved by a specific nuclease to create a double-stranded break. C. Strand invasion of HMLa or HML? is mediated by Rad51. D. As the 3' invading end is extended by DNA polymerase, the HML locus information is copied, whereas the MAT gene information is degraded. E. When the extension has proceeded far enough, it dissociates and reanneals to its original strand.

Which statement is NOT correct about the results of the Hershey-Chase experiment with the T2 virus?

a. Radioactively labeled protein was found in the bacteria, not in the virus coats. b. Radioactively labeled DNA was found in the bacteria, not in the virus coats. c. DNA was labeled with radioactive phosphorus. d. Protein was labeled with radioactive sulfur. e. Two separate experiments were actually run, one with radioactive phosphorus and one with radioactive sulfur.