g In the lac operon (above), what will be the effect on the expression of the lacZ and lacY genes if there is a mutation in the operator sequence (lacO) that prevents the repressor protein from binding to the operator

Which statement describes characteristics of planarians? a they live in oceans, are parasites, and reproduce only sexually. b they live in fresh water, are parasites, and reproduce only asexually. c they live in oceans, are free living, and reproduce sexually and asexually. d they live in fresh water, are free living, and reproduce sexually and asexually.

Plant species a has a diploid number of 12. plant species b has a diploid number of 16. a new species, c, arises as an allopolyploid from a and b. the diploid number for species c would probably be a) 12. b) 14. c) 16. d) 28. e) 56.

Which of the following is a true statements about viruses? viruses have no nucleus. viruses are alive. viruses have a cell membrane. all viruses are deadly.