Calculate the frequency of b cells specific for antigen a on day 36 if the antibody concentration on day 36 is about 8 × 103. (for practice doing calculations with proportions, try this exercise. for practice doing calculations with numbers written in scientific notation, try this exercise.)

Which of the following protists gets nutrients mainly by absorbing molecules from other organisms through their cell walls and cell membranes? a. amoebas b. water molds c. ciliates d. slime molds

2. how does the miller-urey experiment fall short of demonstrating that life can arise from inorganic molecules? explain. a. it doesn't show a leap between a collection of amino acids and a single-celled organism. b. it recreates the conditions that existed at the earth's beginning, but no molecules form as a result. c. it doesn't provide evidence of the formation of amino acids. d. it doesn't show how multicellular organisms developed from unicellular organisms

Construct at least two possible hypotheses for the student’s experiment.