Question

1. two teams of scientists hiked 10 kilometers to different study sites. before their hike, the valley team ate a lunch of mostly protein. the mountain team ate a lunch of a mix of starch and protein, but hiked at high altitude, where there is much less oxygen. which team probably had an easier time hiking? a both teams had an easy time hiking because their digestive systems broke down proteins into amino acids for cells to release energy. b neither team had an easy time hiking; the valley teams cells needed more glucose from broken - down starch for a reaction, and the mountain teams cells needed more oxygen from air. c the mountain team had an easier time hiking; their cells released energy from protein reacting with glucose, which was broken down from starch in the digestive system. d the valley team had an easier time hiking; their cells released energy from protein breaking down in the digestive system, which then combined with oxygen in cells.

Explanation:

• Option a: Proteins are not the primary source of energy for cells during physical activity like hiking. Carbohydrates (such as glucose from starch) are the preferred source. Also, the Mountain team faced an oxygen - limited environment.
• Option b: The Valley team ate mostly protein. Proteins are not easily converted to glucose (the main fuel for cells during exercise) compared to starch. The Mountain team was at high altitude with less oxygen. Cellular respiration (which releases energy) requires oxygen. So, neither team had an easy time. The Valley team lacked sufficient glucose (as starch was not the main component of their lunch) and the Mountain team lacked oxygen.
• Option c: Protein - glucose reaction is not the typical energy - releasing mechanism for cells during physical activity. Glucose from starch is broken down through glycolysis and then (in the presence of oxygen) through the Krebs cycle and electron transport chain. But the Mountain team had an oxygen - deficiency problem.
• Option d: Proteins are not the main source of energy for cells during exercise. Carbohydrates are the primary fuel.

Answer:

B. Neither team had an easy time hiking; the Valley team’s cells needed more glucose from broken - down starch for a reaction, and the Mountain team’s cells needed more oxygen from air.