Ne ol Ealin. Tutorial 30 of 44
B Save & E
Directions
Read the instructions for this self-checked activity. Type in your response to each question, and check your answers. At the
end of the activity, write a brief evaluation of your work.
Activity
A student drew this model to show the flow of convection currents on Earth.
90° desending dry, cold air
66.5°
2
ascending warm,
moist air
ascending warm,
moist air
equator
2
66.5°
90° desending dry, cold air
Part A

You are studying several alleles of an e. coli helicase gene. one allele, called rsr, confers resistance to rs2014, an antibiotic that works by inhibiting helicase activity. bacteria with the rss allele are sensitive to rs2014. another allele, called ts-, produces a temperature sensitive mutation of the helicase. in bacteria with the ts- allele, helicase is inactivated at 42 °c but functions normally at 37 °c. helicase functions normally at both temperatures in bacteria with the ts allele. you obtain the following data while testing four strains of e. coli at different temperatures and doses of rs2014. each number represents the percentage of maximal dna synthesis. based on this data, assign the appropriate genotype to strains a–d in the spaces provided