The Proportion of Fast- and Slow-Twitch Fibers Found in an Individual's

question 138

Multiple Choice

 The proportion of fast- and slow-twitch fibers found in an individual's quadriceps muscle is primarily determined by the

• A) individual's diet.
• B) number of hours the individual spends each week engaged in anaerobic activity, like weightlifting.
• C) the type of ACTN3 genes that person has.
• D) number of hours the individual spends each week engaged in aerobic activity, like running or cycling.

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Definitions:

Planula

The free-swimming, ciliated larva form of certain cnidarians, such as jellyfish, before it settles on a surface and develops into a polyp.

Miracidium

A free-swimming larval stage in the life cycle of certain parasitic flukes, hatching from eggs and infecting the first intermediate host, typically a snail.

Polyp Colony

An aggregation of many individual, yet genetically identical, polyps that are connected, forming organisms such as corals.

Collar Cells

Specialized cells found in sponges (Porifera) that have a collar-like structure and are involved in water filtration and nutrient capture.