Students ask if convection currents are strong enough to move heavy objects. they use a fish tank and a toy boat that floats. then they place the boat in the tank and watch it for 10 minutes. it doesn’t move. next they put a hot plate under one side of the fish tank and turn it on. they watch for a half hour, and at the end of that time, the boat has moved across the aquarium away from the heat. what is a flaw in the experimental design of this experiment? question 14 options: the toy boat should have enough weight to sink. the hot plate should have been used in the first test. the fish tank should have been filled with different liquids. the amount of time should have been the same for both tests.

During a hot day, warm and moist air rises and cools in the atmosphere. which even would occur next on such a day? a. condensed droplets would gather to become water vapor. b. water vapor would condense into tiny droplets. c. water droplets would evaporate to form rain and snow.

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data

Ms. w, a 21-year-old woman, came into a clinic after suffering a deep laceration on her foot while walking barefoot around her yard. the wound was cleaned, sutured, and bandaged, and she was released to return home after receiving tetanus antitoxoid. within 72 hours, the wound area was red and swollen, the suture line was dark in color, and it was accompanied by severe throbbing pain. ms. w had a high fever, her heart felt like it was racing, and she was finding it hard to concentraten even on simple tasks. she returned to the clinic and was immediately taken to the hospital. following lab tests, a diagnosis of acute necrotizing fasciitis was made. discussion questions 1. explain why ms. w. received a tetanus antitoxoid before leaving the hospital. (see chapters 3 and 4, infection and passive immunity.) 2. explain how acute necrotizing fasciitis developed in this case and the pathophysiology involved. (see acute necrotizing fasciitis.) 3. what is the potential outcome for ms. w if antibiotic drugs do not reduce the infection quickly?