CHAPTER 6-DNA AND GENE EXPRESSION

Question 1

Nucleotide

Answer 1

unit of a DNA molecule has three components: a phosphate group, a nitrogenous base and a sugar

Question 2

Base Pairs

Answer 2

DNA bases are connected with hydrogen bonds: A-T(U), G-C

Question 3

DNA and RNA

Answer 3

are nucleic acids consisting of long chains (polymers) of chemical units (monomers) called nucleotides

Question 4

DNA (deoxyribonucleic acid)

Answer 4

nucleic referring to DNA’s location in the nuclei of eukaryotic cells

Question 5

RNA (Ribonucleic acid)

Answer 5

uses the sugar ribose and has nitrogenous base Uracil (U) instead of Thymine (T)

Question 6

Structure of DNA

Answer 6

two polynucleotide strands wrapped around each other in a double helix

Question 7

Genome

Answer 7

an organism’s complete set of DNA – found in the nucleus of almost every cell

Question 8

Chromosome

Answer 8

one or more unique pieces of DNA, they vary in length and can consist of hundreds of millions of base pairs

Question 9

Gene

Answer 9

a specific sequence of DNA on average about 3,000 base pairings long that contains the information necessary for protein synthesis

Question 10

Allele

Answer 10

different versions of a gene that code for the same trait – version of gene expressed is influenced by the environment and in some cases other genes

Question 11

Transcription: SLIDE 26-27

Answer 11

the gene’s sequence is copied from DNA to a middleman molecule called mRNA

Question 12

Translation

Answer 12

the gene’s sequence is now encoded in mRNA which directs the production of a protein

Question 13

Transcription: Recognize and Bind

Answer 13

once RNA polymerase recognizes a promoter site, it binds to one strand of DNA and begins reading the gene’s message

Question 14

Transcription: Transcribe

Answer 14

As the DNA strand is processed through the RNA polymerase, the RNA polymerase builds a single stranded RNA copy of the gene, called the mRNA transcript

Question 15

Transcription: Terminate

Answer 15

when the RNA polymerase encounters a code signaling the end of the gene, it stops transcription and releases the mRNA transcript

Question 16

Transcription: Cap and Process

Answer 16

In eukaryotes, mRNA receive extra processing before thy can be translated into a protein. a cap and tail are often added for protection and to promote recognition and noncoding sections are removed

Question 17

Translation: Recognize and initiate protein building

Answer 17

the START sequence of the mRNA signified by the bases, A, U and G is recognized by the corresponding tRNA molecule and the two ribosomal subunits; the attachment site of the tRNA molecule binds to the mRNA as the ribosomal subunit assemble around them

Question 18

Translation: Elongate

Answer 18

As the ribosome moves along the strand of mRNA, each new amino acid carrying tRNA molecule binds to the next three bases of the mRNA

Question 19

Translation: Terminate

Answer 19

once the ribosome encounters the three base STOP sequence, protein assembly is complete

Question 20

Operon

Answer 20

group of several genes along with the elements that control their expression as a unit all within one section of DNA

Question 21

Promoter

Answer 21

the region of DNA that RNA polymerase recognizes and binds to in order to produce an mRNA transcript of genes

Question 22

Operator

Answer 22

the region of DNA that a repressor protein can bind to and by doing so, block RNA polymerase from transcribing genes

Question 23

Dogma

Answer 23

a principle or set of principles laid down by an authority as incontrovertibly true

Question 24

Point mutations

Answer 24

nucleotide substitution, nucleotide insertion, nucleotide deletion

Question 25

Chromosomal aberrations

Answer 25

Gene deletion, gene relocation, gene duplication