From your knowledge of the cellular mechanism of muscle contraction, propose a

During the contraction of a vertebrate skeletal muscle fiber, calcium ions a. break cross-bridges by acting as a cofactor in the hydrolysis of ATP. b. bind with troponin, changing its shape so that the myosinbinding sites on actin are exposed. c. transmit action potentials from the motor neuron to the muscle fiber. d. spread action potentials through the T tubules. e. re-establish the polarization of the plasma membrane following an action potential.

During the contraction of a vertebrate skeletal muscle fiber, calcium ions a. break cross-bridges by acting as a cofactor in the hydrolysis of ATP. b. bind with troponin, changing its shape so that the myosinbinding sites on actin are exposed. c. transmit action potentials from the motor neuron to the muscle fiber. d. spread action potentials through the T tubules. e. re-establish the polarization of the plasma membrane following an action potential.

According to Hamiltons rule, a. natural selection does not favor altruistic behavior that causes the death of the altruist. b. natural selection favors altruistic acts when the resulting benefit to the recipient, corrected for relatedness, exceeds the cost to the altruist. c. natural selection is more likely to favor altruistic behavior that benefits an offspring than altruistic behavior that benefits a sibling. d. the effects of kin selection are larger than the effects of direct natural selection on individuals. e. altruism is always reciprocal.

The binding of calcium to the troponin complex a. activates myosin kinase, causing phosphorylation of myosin heads. b. disrupts cross-bridges, allowing filaments to slide past each other. c. allows tropomyosin to bind actin. d. opens ion channels, allowing sodium to rush into the muscle cells. e. causes tropomyosin to shift position, exposing myosin bind sites on actin

Curare, a substance that blocks the acetylcholine receptors on skeletal muscle, will cause a. rapid muscle twitches. b. sustained muscle contraction (tetanus). c. muscle relaxation. d. specific disruption of blood pressure and digestive functions. e. no effect in the absence of acetylcholinesterase.

Although many chimpanzees live in environments containing oil palm nuts, members of only a few populations use stones to crack open the nuts. The likely explanation is that a. the behavioral difference is caused by genetic differences between populations. b. members of different populations have different nutritional requirements. c. the cultural tradition of using stones to crack nuts has arisen in only some populations. d. members of different populations differ in learning ability. e. members of different populations differ in manual dexterity

Which of the following is not required for a behavioral trait to evolve by natural selection? a. In each individual, the form of the behavior is determined entirely by genes. b. The behavior varies among individuals. c. An individuals reproductive success depends in part on how the behavior is performed. d. Some component of the behavior is genetically inherited. e. An individuals genotype influences its behavioral phenotype.

From your knowledge of the cellular mechanism of muscle contraction, propose a hypothesis to explain how paramyosin enables clamshell muscles to remain contracted for long periods. How would you test your hypothesis experimentally

Scientists studying scrub jays found that helpers often assist mated pairs of birds in raising their young. The helpers lack territories and mates of their own. Instead, they help the territory owners gather food for their offspring. Propose a hypothesis to explain what advantage there might be for the helpers to engage in this behavior instead of seeking their own territories and mates. How would you test your hypothesis? If it is correct, what results would you expect your tests to yield?

We often explain our behavior in terms of subjective feelings, motives, or reasons, but evolutionary explanations are based on reproductive fitness. What is the relationship between the two kinds of explanation? For instance, is a human explanation for behavior, such as falling in love, incompatible with an evolutionary explanation?

Learning is defined as a change in behavior based on experience. In a short essay (100150 words), describe the role of heritable information in the acquisition of learning, using some examples from imprinting and associative learning.