In a recent experiment, anti-bacterial hand sanitizer was compared to hand soap. Students washed their hands using the sanitizer or soap and warm water for two minutes; then they dried their hands with a paper towel. The standard of comparison was rubbing hands vigorously for 2 minutes in warm water, without any soap or sanitizer, and then drying with a paper towel. The sanitizer advertisement claimed to kill bacteria more effectively than any soap. After washing, hands were swabbed and then the swab applied to a culture plate and incubated. Finally, the bacterial cultures were counted. Students using the antibacterial santizer had the lowest bacterial culture count. What is the control in the experiment? A) washing with soap B) rubbing vigorously C) the time: two minutes D) rubbing hands in warm water

Which best describes red blood cells? a. they are colorless b. they protect against disease-carrying microorganisms c. they transport oxygen throughout the body d. they aid in blood clotting

This is the main structural axis of the plant that supports leaves, flowers and fruits; transports fluids; stores nutrients and produces new tissue.

On a backpacking trip, kenny hikes all day at a steady pace, covering 30 kilometers and burning 4000 calories. at the school track, janelle runs the 100-meter sprint in 13.5 seconds, burning 10 calories. afterward, janelle’s leg muscles are aching and she is breathing hard, while kenny maintains normal breathing all day, even though he burns 400 times more calories than janelle. which two statements offer the best explanation for this phenomenon? a. if the aerobic pathway—cellular respiration—cannot meet the energy demand, then the anaerobic pathway—lactic acid fermentation—starts up, resulting in lactic acid buildup and "oxygen debt." b. aerobic cellular respiration produces more energy, but its use is limited because of lactic acid buildup in the muscles and the resulting "oxygen debt." c. after about 90 seconds of intense exercise, the muscles become depleted of oxygen, and anaerobic respiration can no longer function to produce atp, resulting in "oxygen debt." d. the rate of energy demand determines how the muscles will obtain energy, either from cellular respiration or from lactic acid fermentation if not enough oxygen is present.