What chemical messenger can directly influence gene expression

Indicate whether the following statements about the biases in the fossil record are true or false. a) inland species are more likely to be preserved than marine species b) organisms with hard body parts are more likely to be preserved than are those composed soft tissues. c) species that existed over a larger area are more likely to be preserved than species existing over a smaller area. d) organisms that lived very long ago are more likely to be found as fossils than organisms that lived relatively recently e) the fossils of larger organisms are more likely to be found than the fossils of smaller organisms

Radiometric dating is used to tell the absolute age of materials by studying the decay rate of radioactive isotopes. the decay rates of isotopes are constant and are expressed as .

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