The sphincter between the esophagus and the stomach serves to ________
a. produce digestive enzymes
b. generate peristalsis to propel food
c. block the flow of substances when it is contracted
d. produce bile
c
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Four of the five answers are adaptations for flight in birds. Select the exception
a. sound production b. lightweight bones c. feathers d. efficient respiration e. four-chambered heart
Explain why mutations are almost always neutral or harmful. What will be an ideal response?
Respond to the following statements with reference to the five vitamins listed below.
A. This vitamin functions in carbohydrate metabolism. B. A deficiency of this vitamin causes Beri beri. C. D. This vitamin is a component of the coenzyme NAD. E. This vitamin is a coenzyme involved in protein metabolism and immune function. F. A deficiency of this vitamin causes anemia and neurological disorders and is a coenzyme important in amino acid synthesis.
While walking in your basement, you hear a crunching noise and notice that you have stepped on an organism. You look closely and see part of a segmented body and a few jointed appendages. What phylum does this animal represent?
A) Echinodermata B) Annelida C) Arthropoda D) Chordata