Exam 30: How Animals Move

Which part of this figure depicts the thoracic vertebrae?

Which of the following statements best describes the power stroke of muscle contraction?

Why is a newly molted crab unusually slow and clumsy?

The calcium that triggers muscle contraction is stored in

After reading the paragraph below, answer the questions that follow. When sarcomeres contract, they generate force (tension). However, the amount of force generated depends on the sarcomere length and the amount of thick and thin filament overlap. Below is a figure that details the force-generating properties of a single sarcomere. This figure was modified from a scientific paper by Al Gordon and colleagues from 1966 and is a classic illustration of the relationship between sarcomere length and force. -Mammalian muscles can shorten approximately 35% of their resting length when all sarcomeres contract. If a sarcomere passes through maximal tension generation during this 35% contraction, what is the likely starting point for contraction of a sarcomere?

Muscles that are constantly active, such as those maintaining our body posture, have a high proportion of

Which of the following would have the greatest number of muscle cells per motor unit?

After reading the paragraphs below, answer the questions that follow. Rickets is a softening of the bones that can lead to frequent fractures and skeletal deformities. The legs of a person with rickets tend to bow outward under the force exerted by body weight and movement. British scientists recently found a serious increase in the incidence of rickets and other bone deficiencies among women in Middle Eastern countries who cover their bodies completely to express a form of religious belief, as well as among their breast-fed children. Most of the body's vitamin D, which is necessary for calcium absorption by bone tissue, is obtained through sunlight acting on the skin. Doctors warn that women who completely cover their skin do not get enough sunlight to produce the vitamin D necessary for bone health. This lack of sun exposure also lowers the level of vitamin D in their breast milk, which means that their children may develop the same vitamin D deficiencies. Lack of calcium and phosphorous, which are needed for bone repair and replacement, can also lead to rickets. Rickets caused by a dietary lack of these minerals is more common in developing countries because dairy products and green vegetables, the best sources of calcium, are not commonly eaten. -In rickets, lack of calcium decreases the strength of the mineral matrix of compact bone so that it is unable to

Which of the following structures constitutes part of the axial skeleton?

Acetylcholine (ACh)is released by motor neurons and binds to receptors on muscle cells to initiate action potentials. Some snake venom contains specific toxins that bind irreversibly to these receptors and block acetylcholine's ability to bind. If an animal is bitten by a snake with these toxins in its venom, what do you predict would happen?

If you lay your forearm along a table, you can rotate it so that your hand changes from a palm-down to a palm-up position. This is possible because your radius and ulna join at a

Which of the following lists muscle components in the correct order from smallest to largest?

After reading the paragraph below, answer the questions that follow. When sarcomeres contract, they generate force (tension). However, the amount of force generated depends on the sarcomere length and the amount of thick and thin filament overlap. Below is a figure that details the force-generating properties of a single sarcomere. This figure was modified from a scientific paper by Al Gordon and colleagues from 1966 and is a classic illustration of the relationship between sarcomere length and force. -What portion of the graph would involve myosin forming cross-bridges and going through power strokes?

Which of the following statements regarding exercise is true?

Which part of a bone contains the cells that produce blood cells?

Evolution has provided enormous diversity in the number of vertebrae among vertebrate species. Vertebrae are differentiated during embryonic development by

Which of the following structures is most like an exoskeleton?

The way the tendons in the legs of a kangaroo aid in locomotion is most like

The role of calcium in muscle contraction is to

A motor unit is