Which of the following is the most likely impact of plastic and marine debris on coral ecosystems?
a. microplastics can be ingested by the corals and can smother the reefs.
b. debris can cause the temperature of the water near corals to increase
c. microplastics can increase the numbers of phytoplankton near the reef.
d. it can prevent marine mammals from finding appropriate mates near the reefs.

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