Q10.2:  The mRNA codon 5'-UGU-3' corresponds to 5'-TGT-3' in the DNA coding strand.  Name each type of mutation - and the functional consequence - of the 3' thymidine deoxynucleotide being mutated to C, A, and G with regard to the encoded protein.

Q7. Meselson and Stahl conducted an experiment to prove that the replication of DNA is semi-conservative (a) Replication of DNA is described as 'semi-conservative'. Explain this term. (b) Explain how the DNA molecule replicates. (c) Meselson and Stahl's experiments involved growing bacteria in culture media containing either heavy nitrogen (15N) or light nitrogen (14N). The DNA was then extracted from the bacteria.

Which statements are true? Explain why or why not.1 The different cells in your body rarely havegenomes with the identical nucleotide sequence.2 In E. coli, where the replication fork travels at 500nucleotide pairs per second, the DNA ahead of the fork—in the absence of topoisomerase—would have to rotate atnearly 3000 revolutions per minute.3 In a replication bubble, the same parental DNAstrand serves as the template strand for leading-strandsynthesis in one replication fork and as the template forlagging-strand synthesis in the other fork.4 When bidirectional replication forks from adja-cent origins meet, a leading strand always runs into a lag-ging strand.5 DNA repair mechanisms all depend on the exis-tence of two copies of the genetic information, one in eachof the two homologous chromosomes

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4-10 Assuming that the 30-nm chromatin fiber con- tains about 20 nucleosomes (200 bp/nucleosome) per 50 nm of length, calculate the degree of compaction of DNA associated with this level of chromatin structure. What fraction of the 10,000-fold condensation that occurs at mitosis does this level of DNA packing represent?

GQ7

5’-CCTAGACCATAACAT-3’ What happens to the amino acid sequence above as a result of each of the following mutations in the DNA: Substitution of A with T at position 4?  Addition of T between positions 8 and 9?  Substitution of A with T at position 11? Deletion of A at position 12?   Substitution of C with T at position 7? State the type of mutation for each of the base changes indicated.

Macmillan Learning What factors promote the fidelity of replication during synthesis of the leading strand of DNA? removal of the RNA primers between Okazaki fragments by DNA polymerase I breaks that occur in the leading strand are repaired by DNA ligase prevention of mismatched nucleotides at the replication fork by topoisomerase removal of wrongly inserted nucleotides by the 3'-exonuclease activity of DNA polymerase III Watson-Crick base pairing between the template and leading strand Incorrect

7.25 Describe, base-excision repair, light repair of pyrimidine dimers, nucleotide-excision repair, mismatch repair, and error-prone repair, such as the SOS response.

Pls help ASAP.