Given what you know about the hierarchy of chemical organization, answer the following question. If Los Angeles was a molecule, Orange County was a cell, and California was a tissue, what would the United States be?
|A)||a sister cell|
|B)||an organ system|
Which organ system is primarily responsible for coordinating, regulating, and integrating the various activities of the body?
Which of the following statements best describes endocrine glands?
|A)||Endocrine glands are ductless glands that secrete hormones.|
|B)||Endocrine glands are ductless glands that secrete sweat, saliva, and digestive enzymes.|
|C)||Endocrine glands secrete hormones through a duct.|
|D)||Endocrine glands secrete sweat, saliva, and digestive enzymes through a duct.|
Which of the following is not considered a connective tissue?
Which of the following statements about nerve tissue is false?
|A)||Neurons transmit sensory information to the brain.|
|B)||Both neurons and neuroglia are present in the CNS and PNS.|
|C)||Neurons conduct electrical impulses.|
|D)||All types of cells in nerve tissue conduct electrical impulses.|
Exoskeletons provide excellent protection to internal organs. However, animals that utilize exoskeletons are usually relatively small. Why?
|A)||These animals are only able to produce a limited amount of chitin.|
|B)||Exoskeletons are not living tissue, and therefore they cannot grow.|
|C)||A large exoskeleton would be too heavy to move.|
|D)||During molting, these animals are especially vulnerable to predators and therefore do no usually live long enough to grow bigger.|
Which of the following statements best describes the sliding filament mechanism of muscle contraction?
|A)||Actin and myosin filaments do not shorten, but rather, slide past each other.|
|B)||Actin and myosin filaments shorten and slide past each other.|
|C)||As they slide past each other, actin filaments shorten, while myosin filaments do not shorten.|
|D)||As they slide past each other, myosin filaments shorten, while actin filaments do not shorten.|
What is the role of Ca++ in muscle contraction?
|A)||It binds to tropomyosin, enabling troponin to move and reveal binding sites for cross-bridges.|
|B)||It binds to troponin, enabling tropomyosin to move and reveal binding sites for cross-bridges.|
|C)||It binds to tropomyosin, enabling troponin to release ATP.|
|D)||It binds to troponin, enabling tropomyosin to release ATP.|
Motor neurons stimulate muscle contraction via the release of
Which of the following statements about muscle metabolism is false?
|A)||Skeletal muscles at rest obtain most of their energy from muscle glycogen and blood glucose.|
|B)||ATP can be quickly obtained by combining ADP with phosphate derived from creatine phosphate.|
|C)||Exercise intensity is related to the maximum rate of oxygen consumption.|
|D)||ATP is required for the pumping of the Ca++ back into the sarcoplasmic reticulum.|