chapter 7

Question 1

the hypothesis, proposed by Beadle and Tatum, that each gene is unique and codes for the synthesis of a single enzyme

Answer 1

one gene- one enzyme hypothesis

Question 2

the hypothesis that each gene is unique and codes for the synthesis of a single polypeptide; the restated version of the one gene-one enzyme hypothesis

Answer 2

one gene- one polypeptide hypothesis

Question 3

the fundamental principle of molecular genetics, which states that genetic information flows from DNA to RNA to proteins

Answer 3

central dogma

Question 4

mechanism by which the information coded in nucleic acids of DNA is copied into the nucleic acids of RNA; something rewritten in the same language

Answer 4

transcription

Question 5

mechanism by which the information coded in the nucleic acids of RNA is copied into the amino acids of proteins

Answer 5

translation

Question 6

the end product of the transcription of a gene; is translated by ribosomes into a protein

Answer 6

messenger RNA

Question 7

a carrier molecule that binds to a specific amino acid and adds the amino acid to the growing polypeptide chain

Answer 7

transfer RNA

Question 8

an RNA molecule within the ribosome that bonds the correct amino acid to the polypeptide chain

Answer 8

Ribosomal RNA

Question 9

an enzyme that reads a DNA strand and creates a complementary strand of RNA

Answer 9

RNA polymerase

Question 10

the DNA strand that is copied into an mRNA molecule during gene transcription

Answer 10

template strand

Question 11

the initial RNA transcription product

Answer 11

precursor mRNA

Question 12

the specific coding relationship between bases and the amino acids they specify; the genetic code can be expressed in terms of either DNA or RNA bases

Answer 12

genetic code

Question 13

a group of three base pairs that code for an individual amino acid

Answer 13

codon

Question 14

the codon that signals the start of a polypeptide chain and initiates translation

Answer 14

start codon

Question 15

a codon that signals the end of a polypeptide chain and causes the ribosome to terminate translation

Answer 15

stop codon

Question 16

a nucleotide sequence that lies just before a gene and allows for the binding of RNA polymerase

Answer 16

promoter

Question 17

a region of the promoter that enables the binding of RNA polymerase

Answer 17

TATA box

Question 18

the DNA strand that is not being copied but contains the same sequence as the new RNA molecule

Answer 18

coding strand

Question 19

a sequence of bases at the end of a gene that signals the RNA polymerase to stop transcribing

Answer 19

termination sequence

Question 20

a chain of adenine nucleotides that are added to the 3’ end of the pre-mRNA molecule to protect it from enzymes in the cytosol

Answer 20

poly(A) tail

Question 21

a sequence of seven Gs that is added to the start of a pre-mRNA molecule; ribosomes recognize this site and use it as the site of initial attachment

Answer 21

5’ cap

Question 22

a sequence of DNA or RNA that codes for part of a gene

Answer 22

exon

Question 23

a non-coding sequence of DNA or RNA

Answer 23

intron

Question 24

an enzyme-protein complex that removes introns from the mRNA

Answer 24

spliceosome

Question 25

a protein that binds to introns and signals them for removal

Answer 25

small ribonucleoprotein (snRNP)

Question 26

a process that produces different mRNAs from pre-mRNA (exons and introns), allowing more than one possible polypeptide to be made from a single gene

Answer 26

alternative splicing

Question 27

the complementary sequence of base pairs on a tRNA that corresponds to a codon on an mRNA

Answer 27

anticodon

Question 28

the process by which a tRNA molecule is bound to its corresponding amino acid

Answer 28

aminoacylation

Question 29

a molecule of transfer RNA bound to its associated amino acid

Answer 29

aminoacyl-tRNA

Question 30

a particular system for separating a base pair sequence into readable codons

Answer 30

reading frame

Question 31

a complex that is formed when multiple ribosomes attach to the same mRNA molecule in order to facilitate rapid translation

Answer 31

polysome

Question 32

a hormone produced in the pancreas that lowers the blood glucose level by promoting the uptake of glucose by the body cells

Answer 32

insulin

Question 33

a cluster of genes that contains the DNA sequences to regulate the metabolism of lactose

Answer 33

lac operon

Question 34

the region in the operon that regulatory factors bind to

Answer 34

operator

Question 35

a protein that binds to the operator to repress gene transcription

Answer 35

repressor protein

Question 36

a signal molecule that triggers the expression of an operon’s genes

Answer 36

inducer

Question 37

a signal molecule that binds to a regulatory protein to reduce the expression of an operon’s genes

Answer 37

corepressor

Question 38

a change in a single nucleotide within a gene

Answer 38

point mutation

Question 39

the replacement of one base pair in a DNA sequence by another base pair

Answer 39

substitution

Question 40

the addition of a base pair (small-scale mutation) or larger coding region (large-scale mutation) to a DNA sequence

Answer 40

insertion

Question 41

the removal of a base pair (small-scale mutation) or larger coding region (large-scale mutation) from a DNA sequence

Answer 41

deletion

Question 42

two adjacent bases trading places (small-scale mutation) or the reversal of a sequence of DNA (large-scale mutation)

Answer 42

inversion

Question 43

a difference in the DNA between individuals caused by point mutations

Answer 43

single nucleotide polymorphism (SNP)

Question 44

a mutation that changes a single amino acid in the coding sequence

Answer 44

missense mutation

Question 45

a mutation that results in a premature stop codon

Answer 45

nonsense mutation

Question 46

a mutation that does not alter the resulting sequence of amino acids

Answer 46

silent mutation

Question 47

a shift in the reading frame resulting in multiple missense and/or nonsense effects

Answer 47

frameshift mutation

Question 48

the movement of entire genes or sequences of DNA from one chromosome to another

Answer 48

translocation

Question 49

a mutation that is caused by an error in DNA replication

Answer 49

spontaneous mutation

Question 50

a mutation that is caused by an environmental agent

Answer 50

induced mutation

Question 51

an environmental agent that directly alters the DNA within a cell

Answer 51

mutagen