Suppose you want to isolate E. coli mutants incapable of synthesizing the amino acid arginine. You grow mutagenized bacteria on a master plate of complete defined media and make a replica plate (by pressing a velvet block onto the master plate and then pressing it onto the replica plate—bacteria will be transferred) on media lacking arginine. Colonies that grew on the master plate but not the replica plate are arginine-synthesizing mutants. In this example, the replica plate

Often, caries will develop in an area of the tooth that's not readily accessible. which cavity preparation form defines this? a. retention b. resistance c. outline d. convenience

Two male mice, which we will call male a and male b, are both phenotypically normal. male a was from a litter that contained half phenotypically normal mice and half dwarf mice. the mother of male a was known to be homozygous for the normal igf2 allele. male b was from a litter of eight mice that were all phenotypically normal. the parents of male b were a phenotypically normal male and a dwarf female. male a and male b were put into a cage with two female mice that we will call female a and female b. female a is a dwarf and female b is phenotypically normal. the parents of these two females were unknown, although it was known that they were from the same litter. the mice were allowed to mate with each other, and the following data were obtained: female a gave birth to three dwarf babies and four normal babies. female b gave birth to four normal babies and two dwarf babies. which male(s)mated with female a and female b? male a with both females male a with female b, and male b with female a male a with female a, and male b with female b could not be determined male b with both females

What causes the force that pushes magma from the magma chamber through the pipe and vent of a volcano?