The structure of RNA differs from DNA in that
A) the backbone of RNA contains ribose.
B) RNA contains pyrimidines but not purines.
C) RNA contains purines but not pyrimidines.
D) DNA contains pyrimidines but not purines.
E) DNA contains purines but not pyrimidines.
Ans: A) the backbone of RNA contains ribose.
You might also like to view...
Cerebrospinal fluid is produced by ________ and it ________.
A. dura mater; maintains a stable ionic concentration in the CNS B. capillaries in the dura mater of the ventricles; moistens the surface of the brain C. arachnoid villi in the dura sinus; provides a pathway to the blood for waste D. choroid plexuses in the ventricles; protects the brain from blows to the skull
Of the following muscles that work the hand, which one runs from the humerus to the phalanges and extends the fingers and wrist?
A) palmaris longus B) flexor digitorum superficialis C) extensor carpi radialis brevis D) extensor digitorum
This figure shows the scapula. The feature indicated by number 6 is the ________ border.
A. vertebral B. superior C. anterior D. lateral E. medial
When a person is exposed to temperature extremes, why is it difficult to distinguish hot from cold objects?
A. At extremes, pain receptors are stimulated by both very hot and very cold objects. B. Temperature perception requires more than one type of receptor. C. Most temperature receptors cannot differentiate hot from cold. D. Pain receptors are inhibited by both very hot and very cold objects. E. Temperatures above 37 degrees centigrade actually stimulate the cold receptors.