Question

Use the following formation to answer the next three questions A researcher makes the following hypothesis: endurance because they are able to use angen more effectively athletes who have trained at a high altinde before competing at a low aloitude will have greater The researcher does a search of several studies related to his hypothesis. Experimental Designs of Some Circulatory System Studies The average red blood cell count of a group of people living at a high-altitude was compared with the average red blood cell count of a similar group of people living at a low altitude. Il The average white blood cell count of runners before a high-altitude marathon race was compared with the average white blood cell count of the runners after the race. III The quantity of hemoglobin per millilitre of blood was measured in people who trained at a low altitude and then measured again after these people spent one-month training at a high altitude IV The average platelet count of a group of people living at a high altitude was compared with the average platelet count of a similar group of people living at a low altitude V The concentration of antibodies in a group of people living at a high altitude was compared with the concentration of antibodies in a similar group of people living at a low altitude 26. Two studies described above that would best test the researcher's hypothesis are I and II I and IV II and V III and IV ta 27. Two of the studies described above helped to establish that altitude has an effect on immunity. The studies that this evidence most likely came from are a. I and II b. I and IV c. II and V d. III and V Use the following additional information to answer the next question. Variables in One of the Circulatory System Studies Manipulated variable - Altitude Responding variable - Ability to clot blood Controlled variable - Age of participants 28. The variables listed above most likely came from study b. III e IV d. v

Answer 1

Main Answer:

27. The studies that best test the researcher's hypothesis are a) II and d) V.

Therefore, the correct answer is a) II and d) V.

Step-by-step explanation:

The researcher's hypothesis suggests that athletes who train at a high altitude before competing at a low altitude will have greater endurance due to more effective use of oxygen. Studies II and V directly address this hypothesis. In Study II, the average white blood cell count of runners before and after a high-altitude marathon race provides insights into how altitude may affect the immune system, which is crucial for endurance. Meanwhile, Study V, which compares the concentration of antibodies in people living at high and low altitudes, further explores the potential impact of altitude on immunity and endurance.

Study II examines a relevant aspect of the circulatory system—white blood cell count—before and after a physically demanding activity at high altitude, directly addressing the researcher's hypothesis regarding endurance. On the other hand, Study V delves into the immune system's response by comparing antibody concentrations in individuals living at different altitudes, contributing to the evidence supporting the hypothesis.

These studies collectively help establish that altitude has an effect on immunity, aligning with the researcher's hypothesis. Altitude, as a manipulated variable, is explored in the context of its impact on the ability to clot blood, which is indicative of its broader influence on endurance. The controlled variable, age of participants, ensures a more accurate comparison across groups.

Therefore, the correct answer is a) II and d) V.