Anursing student notes the characteristics of middle-range theories.
which points noted by the nursing student are accurate? select all that apply.

a. middle-range theories are systematic and broad in scope and complexity.
b. middle-range theories provide a basis to nurses understand how clients cope with uncertainty and the illness response.
c. middle-range theories do not address a specific phenomenon and do not reflect practices such as administration, clinical, or teaching.
d. middle-range theories include mishel's theory of uncertainty in illness, which focuses on a client's experiences with cancer while living with continual uncertainty.
e. middle-range theories tend to focus on a specific field of nursing (such as uncertainty, incontinence, social support, quality of life, and caring) rather than reflect on a wide variety of nursing care situations.

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