USABO Open Exam 2010 with 100% complete answers

Both amino acids and nucleotides form complex chains. Select all the answers below that are accurate. A. The chains formed by both have polar phosphate groups. B. Both contain peptide bonds. C. Both contain nitrogen. D. The chains formed by both can be lysed by trypsin. E. The sequence of chains both form from preexisting templates. correct answersC. Both contain nitrogen. E. The sequence of chains both form from preexisting templates. When a population is in Hardy-Weinberg equilibrium, which of the following is true? A. All of its recessive lethal genes are wiped out, leaving only healthy dominant genes. B. dN/dt = 0, N = population size. C. Mutations occur at five times the normal rate to balance the loss of genes by way of natural selection. D. The frequencies of the alleles in the population change over time. E. The frequencies of genotypes in the population are stable over time. correct answersE. The frequencies of genotypes in the population are stable over time. Which of the following is NOT an accurate description of protein synthesis and folding? A. All protein synthesis is initiated in the cytoplasm. B. Many copies of a protein can be synthesized simultaneously from the same mRNA. C. The 3D shape of a protein is determined largely by its amino acid sequence. D. The entire chain of amino acids exits the ribosome before it begins folding into its 3D shape. E. The first encoded amino acid in every protein is methionine. correct answersC. The 3D shape of a protein is determined largely by its amino acid sequence.