Use the Following Information to Answer the Question(s) Below

question 16

Multiple Choice

Use the following information to answer the question(s) below.
The mechanism of cell crawling in protist species is not well defined. Pseudopodia extension involves interactions between actin and myosin (the same molecules that are involved in vertebrate muscle contraction) . However, prior to the study described below, no one had provided convincing data that actin and myosin were actually involved in cell crawling in protists. Anatomical studies had identified the cytoskeletal protein actin just below the surface of the cell membrane in several species of protist, but physiological studies had failed to show a functional link between actin, myosin, and cell crawling.
In a study by N. Poulsen et al. (Diatom gliding is the result of an actin-myosin motility system, Cell Motility and the Cytoskeleton 44 (1999) :23-22) , researchers tested whether motility in a particular species of diatom involves interactions between actin and myosin.
-Refer to the study by Poulsen et al. and the accompanying figure. Cultures of a species of diatom were treated with BDM, a reversible inhibitor of myosin function. Which of the following predictions is consistent with the hypothesis that an actin-myosin interaction is necessary for motility?

• A) BDM will significantly decrease motility of the cells in culture.
• B) BDM will not significantly alter motility of the cells in culture.
• C) BDM will significantly increase motility of the cells in culture.

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Definitions:

Capillary Refill Time

A quick test performed to estimate blood circulation, where a fingernail is pressed to turn it white and the time for color to return is measured.

Venous Insufficiency

A condition characterized by inadequate blood flow in the veins, leading to symptoms such as swelling, varicose veins, and leg discomfort.

Brachial

Pertaining to the arm, specifically the area from the shoulder to the elbow.