Carlos is trying to determine how music affects the growth of bean plants. He hypothesizes that classical music will cause a plant to grow at a higher rate than no music or rap music. He grows nine bean plants in similar
lighting, temperature, and soil conditions. Three are exposed to classical music 24 hours a day, three are exposed
to rap music 24 hours a day, and three are grown in complete silence. Carlos measures the growth of the plants
every day and finds that the plants all seem to have the same rate of growth.
What is missing from Carlos's scientific investigation? (2 points)
A specific hypothesis predicting a relationship between independent and dependent variables
o Controlled variables to ensure only the independent variable is being changed
Experimental data collected regularly that can be recorded and analyzed
Research on what other scientists have observed and investigated on this topic.

Many bird species build nests in which they raise their offspring. one of these species is known as the magnolia warbler. breeding pairs of magnolia warblers build nests out of pieces of grass and twigs. the female warbler will then lay her eggs in the nest and sit on the eggs for a few weeks until they hatch. after the offspring have hatched, the female will continue to sit on the newborn chicks to keep them warm. both the male and the female bring food for the offspring to eat until the young are mature enough to find food on their own. which of these most likely describes why birds such as the magnolia warbler build nests in which to raise their offspring? a. nest building decreases the amount of energy used by the parent birds to raise their offspring to adulthood. b. nest building increases the probability that the offspring will survive and eventually produce offspring of their own. c. nest building decreases the amount of food that the offspring require the adult birds to provide. d. nest building increases the probability of the offspring being located by airborne predators.