Chapter 11 Gene Expression and Regulation

Question 1

Anticodon

Answer 1

A sequence of three bases in transfer RNA that is complementary to the three bases of a codon messenger RNA.

Question 2

Codon

Answer 2

A sequence of three bases of messenger RNA that specifies a particular amino acid to be incoprated into a protein; certain codons also signals the beginning or end of protein synthesis.

Question 3

Deletion Mutation

Answer 3

A mutation in which one or more pairs of nucleotides are removed from a gene.

Question 4

Gene

Answer 4

A unit of herdity that encodes the information needed to specify the amino acid sequence of proteins and hence particular traits; a functional segment of DNA located at a particular place on a chromosone.

Question 5

Genetic Code

Answer 5

The collection of cdons of messenger RNA (mRNA), each of which directs the incorporation of particular amino acid into a protein during protein synthesis.

Question 6

Insertion Mutation

Answer 6

A mutation in which one or more pairs of nucleotides are inserted into a gene.

Question 7

Messenger RNA (mRNA)

Answer 7

A strand of RNA, complementary to the DNA of a gene, that conveys the genetic information in DNA to the ribosomes to be used during protein synthesis; sequences of three bases (codons) in mRNA specify particular amino acids to be incorporated into a protein.

Question 8

Mutation

Answer 8

A change in the base sequence of DNA in a gene; normally refers to a genetic change significant enough to alter the appearance or function of the organism.

Question 9

Nucleotide Substitution

Answer 9

A mutation that replaces on nucleotide in a DNA molecule with another; for example, a change from an adenine to a guanine.

Question 10

Point Mutation

Answer 10

A mutation in which a single base pair in DNA has been changed.

Question 11

Promoter

Answer 11

A specific sequence of DNA to which RNA polymerase binds, initiating gene transcription.

Question 12

Ribonucleic Acid (RNA)

Answer 12

A molecule composed of a ribose nucleotides, each of which consists of a phosphate group, the sugar ribose, and one of the bases adenine, cytosine, guanine, or uracil; transfers herditary instructions from the nucelus to the cytoplasm; also the genetic material of some viruses.

Question 13

Ribosomal RNA (rRNA)

Answer 13

A type of RNA that combines with proteins to form ribosomes.

Question 14

Ribosome

Answer 14

An organelle consisting of two subunits, each composed of ribosomal RNA and protein; the bases of messenger RNA is translated into the sequence of amino acids in a protein.

Question 15

RNA Polymerase

Answer 15

In RNA synthesis, an enzyme that catalyzes the bonding of free RNA nucleotides into a continous strand, using RNA nucleotides that are complementary to those of a strand of DNA.

Question 16

Start Codon

Answer 16

The first AUG codon in a messenger RNA molecule.

Question 17

Stop Codon

Answer 17

A codon in messenger RNA that stops protein synthesis and causes the completed protein chain to be released from the ribosome.

Question 18

Template Strand

Answer 18

The strand of the DNA doble helix from which RNA is transcribed.

Question 19

Transcription

Answer 19

The synthesis of an RNA molecule from a DNA template.

Question 20

Transfer RNA (tRNA)

Answer 20

A type of RNA that binds to a specific amino acid byt means of a set of three bases (the anticodon) on the tRNA that are complementary to the messenge RNA (mRNA) codon for that amino acid; carries its amino acid to a ribosome during protein synthesis, recognizes a codon of mRNA, and positions its amino acid for incorporation into the growing protein chain.

Question 21

Translation

Answer 21

The process whereby the sequence of bases of messenger RNA (mRNA) is converted into the sequence of amino acids of a protein.