Chapter 7 SmartBook

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 the reasons a cell regulates gene expression.

to respond to changing conditions to have a specialized function

At the beginning of transcription, RNA polymerase binds to

the promoter.

The term genome refers to

all the genetic material in an organism's cell.

A variant of a gene is referred to as a(n)

allele

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

alleles

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

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

mutation

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

mutation

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

mutation.

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

mutations

Select all of the following that are components of nucleotides.

nitrogen-containing base sugar phosphorus-containing groups

Place these translation initiation and elongation events in order from the first step at the top to the last step at the bottom.

1. The 5' end of the mRNA molecule binds with the small ribosomal subunit.2. The first tRNA binds to the start codon on the mRNA molecule.3. The large ribosomal subunit binds to the small ribosomal subunit.4. The second tRNA molecule binds to the second codon on the mRNA molecule.5. A covalent bond is formed between the two amino acids.6. The ribosome releases an empty tRNA.

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.

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

Blank 1: intron or Introns

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.

Blank 1: mRNA, RNA, or messenger rna Blank 2: amino

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

Blank 1: transcription Blank 2: translation

Hershey and Chase showed that the part of a virus that could enter bacterial cells and cause the production of more viruses was

DNA

Select all the statements about nucleotides that are accurate.

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

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

DNA.

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.

Select all of the following that are true about codons.

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

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

True

Explain the data shown in the image, as it relates to FOXP2, the "language gene."

Two amino acids have changed in the human FOXP2 protein relative to an ancestor.

Regulating gene expression allows cells to produce

certain proteins only when they are needed.

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

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

developmental patterns cell division gene expression

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

errors in DNA replication chemical mutagens some forms of radiation

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

eukaryotes animals archaea

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

The ______ describes the correspondence of three-nucleotide codons to specific amino acids or directions for starting and stopping translation.

genetic code

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

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

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

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

proteins

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

ribosome mRNA amino acids tRNA