After researching the possible effects of music, Elaina proposes that if people listen to faster-paced music, their pulse rates
will increase more than if they listen to slower music. Her mother listens to classic rock at a high volume for 30 minutes, her younger brother listens to classical music quietly while he sleeps at night, and her grandmother listens to two hours of rap at a medium volume. Elaina records each person's pulse before and after listening to the music. What is missing from Elaina's scientific investigation?
Elaina's investigation lacked the critical ingredient of constant variables which are important components of every scientific investigation. In every research, there are 3 important variables, namely:
1. Dependent variables: the actual variable to be measured during the course of investigations and whose values are dependent on another variable (independent variable) supplied by the investigators.
2. Independent variable: one of the variables that are supplied by investigators whose values are often manipulated to see the kind of changes it will cause to the dependent variable.
3. Constant variables: other variables that are neither independent nor dependent but constant for all the various experimental groups in investigations.
Assuming there is no typo with the genotypes, both parents are recessive in both traits. Therefore the phenotype of the offspring can only show recessive traits,namely green and short. In otherwords, the probability of having green and short phenotypes is 100%.
Drugs hit the same part of the brain that releases dopamine which makes you happy. Other things that by this part of the brain are good and sex. This part of the brain is called the "reward" circuit , which is part of the limbic system.
