To create a knockout mouse, after introducing to ES cells a DNA construct in which a specific gene is mutagenized by the insertion of a drug resistance marker, the cells Multiple Choice that have incorporated the transgene by homologous recombination grow in the presence of the drug and these are injected into a host blastocyst. that lack the transgene grow in the presence of the drug and these are injected into a host blastocyst. that have deleted the transgene grow in the presence of the drug and the nuclei are injected into a host blastocyst. that lack the transgene grow in the presence of the drug and the nuclei are used for nuclear transfer.

You will create a molecular clock model for an arthropod gene. follow these guidelines to make your model: . your timeline will span from 90 million years ago to the present. the common ancestor in your model is an arthropod that lived 90 million years ago. the gene that you'll track codes for a protein in the species venom . the dna sequence youll track contains 10 nitrogen bases. you can choose the order of the bases and where the mutations occur. this gene mutates at a rate of approximately 0.76 base pairs every 17.1 million years. to build your model,/ calculate the estimated time period it takes for 1 base pair to mutate. the first time period will only show the common ancestor. at the beginning of the second time period, three lineages will diverge from the common ancestor, each with a different mutation in their gene sequences. the first and third descendant species will survive for the rest of the timeline. the second descendant species was extinct 50 million years ago. calculate how long it will take for one full base pair mutation to occur. explain your reasoning by constructing a mathematical equation