What initiates an action potential on a muscle cell?
a. acetylcholine binding to receptors on the sarcolemma within the neuromuscular junction
b. acetylcholinesterase
c. myosin cross bridges binding to actin
d. atp?

What have we learned from fossil evidence about evolution? a) it is an abrupt change. b)the process is observable. c) it takes place during one lifetime only. d)the most complex traits are always selected.

3points hurry! what is the relationship between biotechnology, sharkskin, and disease resistance? bioengineers have developed an artificial sharkskin that does not allow resistant bacteria to grow on it. disease-causing microbes have been genetically modified to keep them from infecting the skins of sharks. scientists have created a device that can be attached to the skins of sharks that dramatically increases their abilities to resist disease. sharkskin produces many chemicals that can be collected and used to create antibiotics.

During which conditions would a river most likely develop? when evapotranspiration exceeds precipitation when it rains more than it snows when precipitation equals evapotranspiration when precipitation exceeds evapotranspiration