Discuss some of the important factors responsible for the diversity of muscle types
What will be an ideal response?
Answer: The driving force behind the diversity of muscle types in more complex animals was the trend toward greater body size. Diffusion of respiratory gases work well for small animals, however, simple diffusion cannot meet the demands of larger animals. Thus, the evolution of genes for muscle protein was combined with evolution of primitive respiratory and circulatory systems. For example, in arthropods, muscles control both ventilation and movement.
Vertebrates, however, show the greatest diversity in muscle types. Two rounds of genome duplication occurred in ancestors of vertebrates, resulting in extra copies of genes for muscle proteins, which enabled the evolution of specialized muscle types. As land animals evolved, they had to adapt to challenges of movement on land combined with weight of gravity, and the challenges were met by evolution of muscle genes resulting in muscle specialization and diversification.
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Answer the following statement true (T) or false (F)
The brain and spinal cord together compose the
A) visceral nervous system. B) somatic motor division of the nervous system. C) autonomic division system. D) central nervous system. E) peripheral nervous system.
The prefix ________ means "under."
A) sub- B) super- C) supra- D) eu-
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A) in all body regions and buried deep in the dermis B) beneath the flexure lines in the body C) in the axillary and anogenital area D) in the palms of the hands and soles of the feet