Ch.7

Select all of the following that are true about the genetic code.

-AUG encodes methionine and "start." -There are three codons that act as "stop" codons. -The same genetic code is used by nearly all species.

Select all of the following that are utilized in the process of translation.

-amino acids -ribosome -mRNA -tRNA

During production of a protein, the information encoded in a DNA base sequence is transcribed to produce a molecule of ________ , which is then processed and translated to produce the sequence of ________ acids in a protein.

-mRNA -amino

During the production of a protein, the information encoded in a DNA base sequence is transcribed to produce a molecule of _______ , which is then processed and translated to produce the sequence of ________ acids in a protein.

-mRNA -amino

Select all of the following that are components of nucleotides.

-sugar -phosphorus-containing groups -nitrogen-containing base

Select all the reasons a cell regulates gene expression.

-to have a specialized function -to respond to changing conditions

Regulating gene expression allows cells to produce

certain proteins only when they are needed.

In the Hershey and Chase experiment, ______ was found inside the infected bacteria, indicating that the labeled viral ______ had entered the bacterial cells to direct new virus production.

radioactive phosphorus; DNA

In his experiments with S. pneumoniae bacteria and mice, Frederich Griffith found that

something in heat-killed S bacteria could transform type R bacteria.

What role does DNA play in the cell?

store genetic information

A(n) ______ mutation is caused by the replacement of one nucleotide with another.

substitution

Select all of the correct statements regarding the results of Frederick Griffith's 1928 experiment involving Streptococcus pneumoniae.

-Live S strains caused pneumonia in mice. -Heat-killed S strains mixed with live R strains caused pneumonia in mice.

The information that each cell needs to produce proteins is stored in a molecule called

DNA

The term genome refers to

all the genetic material in an organism's cell.

Mutations can lead to genetic variability because they create new ________ , or variants of genes.

alleles

What gene regulation mechanism allows for the production of different proteins from the same mRNA?

alternative splicing of exons

On a tRNA molecule, the _________ is a three-base sequence that is complementary to and binds to an mRNA codon during translation.

anticodon

What 3-base site of a tRNA molecule is complementary to an mRNA codon?

anticodon

Epigenetics is the study of changes in gene expression due to

chemical modifications of histones or DNA bases.

In an RNA molecule, a(n) ______ is a genetic "code word" that corresponds to one amino acid.

codon

The genetic code specifies what amino acid is matched to each three-nucleotide ______ in the mRNA.

codon

In the Hershey and Chase experiment, radioactively-labeled sulfur was found in the ______ within one test tube, while radioactively-labeled phosphorus was found in the ______ within the other test tube, indicating that ______ was the genetic material.

fluid; bacterial cells; DNA

After translation is complete, the newly synthesized polypeptide must ______, as determined by some regions of the amino acid chain.

fold into its functional shape

All of the genetic material that is within a cell is called its

genome

A(n) _______ mutation is one that occurs in the cells that give rise to sperm or egg.

germline

A(n) ________ is a portion of RNA that averages about 1,000 nucleotides long and that is removed before translation.

intron

In eukaryotes, a part of an mRNA molecule that is removed before translation is called a(n)

intron

As described by Jacob and Monod, what E. coli genes and regulatory sequences are only produced when the bacteria need to break down lactose in the immediate environment?

lac operon

The lac operon in E. coli bacteria includes three genes that produce

lactose-degrading proteins.

In transcription, the genetic information in DNA is copied into a(n) ______ molecule, and in translation, the "message" in an mRNA molecule is translated into a(n) ______ sequence.

mRNA; amino acid

During the elongation stage of translation, the ribosome exposes codons on the ______ one at a time; each codon determines what ______ will bring its attached amino acid to the ribosome to be added to the polypeptide chain.

mRNA; tRNA

A change in a protein-encoding DNA sequence or a regulatory DNA sequence, such as an enhancer, is called a(n)

mutation

A(n) __________ is a change in a cell's DNA sequence.

mutation

Because of ______, the "language gene" (FOXP2) in humans has two unique amino acids compared to other primates.

mutations

______ in DNA may arise spontaneously as errors in replication, or they can be induced by external agents, like chemicals and radiation.

mutations

What describes a substitution mutation?

one DNA base is replaced with another

Enzymes and chaperone proteins assist in ______ that takes place after translation is complete.

polypeptide folding

Splicing of different exons together from the same mRNA molecules can result in

production of different proteins.

The ______ is a sequence of DNA that signals the start of a gene and is the site where RNA polymerase binds to begin transcription.

promoter

In the "central dogma," information flows from DNA to RNA to

proteins

At the beginning of transcription, RNA polymerase binds to

the promoter.

In eukaryotic cells, proteins called ______ factors bind at specific DNA sequences, which allows RNA polymerase to initiate transcription.

transcription

In eukaryotes, what regulatory proteins are required for RNA polymerase to bind to the promoter and initiate transcription?

transcription factors

True or false: A mutation that occurs in a sperm cell has the potential of being passed on to the next generation.

true

Select all the statements about nucleotides that are accurate.

-They are composed of a sugar, a nitrogen-containing group, and one or more phosphorus-containing groups. -DNA always contains the same sugar in its nucleotides.

Select all of the following that are true about codons.

-They are composed of three mRNA bases. -They correspond to one amino acid.

Select all of the following organisms that have introns in their primary mRNA transcripts.

-archaea -animals -eukaryotes

Select all of the following agents or processes that can cause mutations.

-chemical mutagens -errors in DNA replication -some forms of radiation

Select all of the following that are affected by epigenetic modifications in eukaryotes.

-gene expression -developmental patterns -cell division

In the "central dogma" describing the flow of genetic information from DNA to protein, DNA is copied to RNA in a process called ______ , and the information in RNA is used to direct the synthesis of a protein in a process called ________ .

-transcription -translation