Muscular Dystrophy Is a Group of Inherited Disorders That Lead

question 4

Multiple Choice

Muscular dystrophy is a group of inherited disorders that lead to increasing muscle cell loss and thus muscle weakness over time. There are many different types of muscular dystrophy. Symptoms can vary, although all involve muscle weakness. Duchenne muscular dystrophy (DMD) is a recessive X-linked form that leads to muscle degeneration and death usually by age 25. Symptoms begin before age 5 and include low endurance and difficulties standing. As the condition progresses, muscle tissue is replaced with adipose and other types of connective tissue. Abnormal bone development and some neurobehavioral and learning disabilities may also occur. DMD occurs as a result of a mutation in a single gene on the X chromosome. This gene codes for a particular protein, dystrophin, which plays a major role in the structure of muscle cells. The protein formed by the mutated gene is nonfunctional, and the absence of a functional protein eventually leads to cell death. Bone and adipose are examples of __________.

• A) connective tissue
• B) muscle tissue
• C) organ systems
• D) cell types

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Definitions:

Factorial Analysis

An analytical technique for interpreting the variability in observed, correlated variables through fewer unseen variables termed factors.

Interaction Effects

Occur when the effect of one variable depends on the level of another variable in statistical models.

Independent Variables

Variables that are manipulated or changed in an experiment to test their effects on dependent variables.

Planning Beyond

A strategic approach focusing on setting long-term goals and objectives beyond the usual planning horizon.