Rods are a. units of measurement for brightness. b. sensory receptors in your eyes. c. the smallest difference threshold. d. a type of vision stimulus.

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food