McGraw hill DNA structure and gene function

Watson and Crick were able to use Blank______ about proportions of bases in DNA and the pattern revealed by Franklin's Blank______ to deduce and build a model showing the double helical structure of DNA.

"Chargaff's rule"; X-ray diffraction

What is an allele?

A similar but slightly different form of the same gene.

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

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

What molecule in all cells is copied before cell division and carries the genetic information for the production of proteins to the next generation of cells?

DNA

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 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.

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.

RNA;amino

Select all of the following that are true about codons.

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

Select all the reasons a cell regulates gene expression.

To respond to changing conditions To have a specialized function

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

True

What scientists built a model revealing that the structure of DNA is a double helix?

Watson and Crick

What scientists worked out the double helical structure of DNA using a ball-and-stick model?

Watson and Crick

What is a mutation?

a change in the nucleotide sequence of a gene

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

What represents Chargaff's discovery about the amounts of the nitrogenous bases A, G, C, and T in the DNA molecule?

amount of A = amount of T; amount of G = amount of C

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

anticodon

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

In Blank______, the lac operon is a group of genes and their regulatory elements that increase production of lactose-digesting enzymes only when Blank______is present in the environment, which maximizes efficiency.

bacteria; lactose

Select all of the following that are true about frameshift mutations.

can be caused by the addition of one nucleotide likely to change the amino acid sequence can be caused by the deletion of two nucleotides disrupts the codon reading frame

The regulation of gene expression in eukaryotic cells allows for

cell specialization in multicellular eukaryotes.

A germline mutation is a DNA sequence change that occurs in

cells that give rise to sperm and eggs.

Epigenetics is the study of changes in gene expression due to

chemical modifications of histones or DNA bases.

In an RNA molecule, a(n) Blank______ 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 Blank______ in the mRNA.

codon

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

developmental patterns cell division gene expression

In humans, the production of the protein keratin in hair follicle cells and the protein hemoglobin in red blood cells is made possible by expressing

different subsets of genes in different cells.

DNA has a Blank______ helical structure consisting of two intertwining strands of Blank______.

double; nucleotides

A eukaryotic transcription factor may bind to a promoter or to a(n) ____________________, a regulatory region on the DNA that lies outside the promoter and regulates transcription

enhancer

n eukaryotes, transcription factors can bind at near or distant regulatory DNA sequences called

enhancers

Modifications to DNA, such as methylation, that do not change the nucleotide sequence but do affect gene expression are called Blank______ modifications.

epigenetic

Mutations caused by Blank______ are example of spontaneous mutations, which occur without outside causes, such as mutagens.

errors in DNA replication or meiosis

While cells constantly produce proteins Blank______, cells regulate the production of many proteins due to the high costs gene expression.

essential to basic functions

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

eukaryotes archaea animals

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

fluid; bacterial cells; DNA

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

fold into its functional shape

Some of the mutations that cause cystic fibrosis are Blank______ mutations resulting from the addition or deletion of just one or two nucleotides.

frameshift

An organism's genome is all of the Blank______ in one of its cell.

genetic material

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

genome

In eukaryotic cells, chemical modifications added to Blank______ proteins can unwind and expose Blank______, making it more available for transcription.

histone; DNA

A(n) _____________-is a portion of RNA that averages about 1,000 nucleotides long and 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

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

mRNA; amino acid

During the elongation stage of translation, the ribosome exposes codons on the Blank______ one at a time; each codon determines what Blank______ 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

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

mutations

Subunits called Blank______ are the building blocks of nucleic acids, as determined by scientists by about 1930.

nucleotides

What describes a substitution mutation?

one DNA base is replaced with another

Enzymes and chaperone proteins assist in Blank______ 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 Blank______ 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

Transcription factors can bind to Blank______ called enhancers, which can be located thousands of base pairs away from genes.

regulatory DNA sequences

Select all of the following that are components of nucleotides.

sugar nitrogen-containing base phosphorus-containing groups

The promoter is a sequence on the Blank______ that signals the start of a gene.

template strand of DNA

At the beginning of transcription, RNA polymerase binds to

the promoter

In the 1950s, the biochemist Erwin Chargaff found that in DNA, the amount of the nucleotide base adenine always equals the amount of the nucleotide base _______________and the amount of the nucleotide base cytosine always equals the amount of the nucleotide base_________________-

thymine; guanine

Select all of the reasons why eukaryotic cells regulate gene expression.

to coordinate early development to express different subsets of genes in different types of cells to activate different genes at different times in the life of an organism

Eukaryotic cells can compact their DNA or add methyl groups to make their DNA unavailable for

transcription

In eukaryotes, what regulatory proteins bind to specific DNA sequences, form a pocket for RNA polymerase, and help initiate transcription?

transcription factors

Transcription factors are eukaryotic proteins that bind to a promoter or enhancer, attract RNA polymerase, and help initiate

transcription of genes

Eukaryotic cells can compact their DNA or add methyl groups to make their DNA unavailable for

transcription.

In eukaryotic cells, proteins called Blank______ factors bind at promoters or enhancers and form a pocket for Blank______ to initiate transcription.

transcription; RNA polymerase

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

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 small ribosomal subunit binds to the 5' "cap" end of the mRNA molecule. 2. A tRNA carrying the amino acid methionine binds to the start codon on the mRNA molecule.  3. The large ribosomal subunit binds to the small ribosomal subunit. 4. A tRNA molecule carrying the second amino acid binds to the second codon on the mRNA molecule.  5. A covalent bond is formed between the two amino acids. 6. The ribosome reteases an empty tRNA.