At the Beginning and End of a 10-Week Exercise Program

question 33

Multiple Choice

At the beginning and end of a 10-week exercise program the subjects have their lung vital capacity measured by the researchers. The readings are plotted on a graph and then the results are recorded. Which of the following can pose a threat to the internal validity in this study?

• A) Instrumentation
• B) Selection
• C) Setting
• D) Testing

---

Definitions:

Areolar Connective Tissue

Areolar connective tissue is a loose connective tissue that supports and cushions organs, and is characterized by a matrix with collagen and elastin fibers.

Serous Acinus

A cluster of cells found in serous glands that produce watery, enzyme-rich secretions.

Mucous Acinus

A secretory unit of a gland that produces mucous, typically found in salivary glands and other mucous-secreting glands.

Acinar Cell

A cell of the exocrine glands that is responsible for producing and releasing certain substances, such as enzymes in the pancreas.