An experimenter wants to know which type of light bulb promotes the most plant growth. He plants 50 pea plants in a room under GE brand light bulbs and another 50 pea plants under Phillips brand light bulbs. Water, temperature, soil type, and other conditions are kept the same between both groups of plants. He allows both groups of plants to grow for 30 days and records the growth of each plant twice daily. The rate at which the plants grow is the

The images show two species of tree frogs in a particular region. the gray tree frogs are adapted to the trees of the woodlands, while the green tree frogs can survive in woodlands or grasslands. the gray frog was abundant in the woodlands. because of climatic changes, most of the trees in the region died, and the woodlands changed to grasslands. in such a case, the . the gray tree frog is closely related to the green tree frog genetically, but they have different mating calls. this suggests that speciation occurred because of .