Bud

A daughter cell formed by mitosis in yeast; one daughter cell retains the cell wall of the parent, and the other (the bud) forms a new cell wall; Rudimentary shoot of flower; a gemma.

Megabase

Unit of length for DNA fragments equal to 1 million nucleotides and roughly equal to 1 cM.

Back Mutation

The process that causes reversion. A change in a nucleotide pair in a mutant gene that restores the original sequence and hence the original phenotype.