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3. a farmer wants to expand his fields, but only has hills left. he is worried about water erosion because of the rate at which water is pulled down
the hills during rainstorms. what can this farmer do to reduce the water erosion he fears?

a)rotate his crops so that there is permanent groundcover.

b)reshape the hills with terraces.

c)use contour plowing on the hills.

d)install silt fences at the bottom of the hills.

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