Chapter 9 - Microbial Genetics

Question 1

P site

Answer 1

holds the tRNA that carries the growing polypeptide chain

Question 2

A site

Answer 2

holds the tRNA that carries the next amindo acid to be added to the chain

Question 3

E site

Answer 3

is the exit site, where discharged tRNAs leave the ribosome

Question 4

constituitive enzymes

Answer 4

synthesized constantly

Question 5

inducible enzymes

Answer 5

not routinely produced; synthesize only when needed

Question 6

repressible enzymes

Answer 6

produced routinely; turned off when not required

Question 7

spontaenous mutations

Answer 7

random change in the DNA due to errors in replication that occur without known cause

Question 8

induced mutations

Answer 8

result from exposure to known mutagens, physical (primarily radiation) or chemical agents that interact with DNA in a disruptive manner

Question 9

point mutation

Answer 9

addition, deletion, or substitution of a base

Question 10

missense mutation

Answer 10

causes change in a single amino acide

Question 11

nonsense mutation

Answer 11

changes a normal codon into a stop codon

Question 12

silent mutation

Answer 12

alters a base but does not change the amino acid

Question 13

back-mutation

Answer 13

when a mutated gene reverses to its original base composition

Question 14

frameshift mutation

Answer 14

when the reading frame of the mRNA is altered