Problem 21.12 Histone genes are unusual among eukaryotic genes because they do not have introns, and histone mRNAs do not have poly(A) tails. Moreover, in almost all eukaryotes, histone genes are arranged in multiple tandem domains, each domain carrying one copy of each of the five histone genes. Part A Explain these features in terms of the special requirements for histone synthesis. Drag the terms on the left to the appropriate blanks on the right to complete the sentences. translation Histones are required in large amounts during only one brief period in the cell cycle - the beginning of S phase nucleomeres They are required in equivalent amounts, to make . The presence of multiple copies aids in rapid introns translation, with equal amounts of each histone being produced. G1 phase nucleus S phase The absence of eukaryotic genes can be avoided, so that histone mRNAs can be delivered rapidly, and in equal amounts, to the and poly(A) tails means that two of the major steps in most exons G2 phase transcription processing silencing cytoplasm nucleosomes replication