A point mutation involving substitution of one base pair for another by replacement of one purine by another purine and of one pyrimidine by another pyrimidine but without change in the purine-pyrimidine orientation.
What Are Transition Words?Good transitions connect one sentence or paragraph to the next. A word, phrase, or sentence can serve as a transition to help make a shift in relationship, space, or time. Transitions connect ideas and supporting examples. They signal the coming of additional information or a conclusion. Transitions in Relationship Some transition words and phrases are used to compare and contrast. These include comparable to, in …
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.