Dr. Liza conducted a sleep study in which half of the volunt…

Dr. Liza conducted a sleep study in which half of the volunteers were randomly assigned to scroll through their friends’ photos on social media right before bedtime. The other half of the volunteers were told to avoid screens at bedtime. Dr. Liza measured the length of time it took for the volunteers to fall asleep once they got into their beds.   Which body chemical is most implicated in Dr. Liza’s research?

(03.01 MC)While sitting on a picnic blanket at the park, Sam…

(03.01 MC)While sitting on a picnic blanket at the park, Sami didn’t notice ants swarming around her feet and repeatedly biting her. The bites were very itchy, and her feet became swollen. Now each time she goes to the park for a picnic, she feels itchy and uncomfortable. What is feeling itchy and uncomfortable just by going to the park in this scenario?