Bio Ch. 7

Select all of the following that are true about prokaryotic versus eukaryotic gene expression.

- In eukaryotes, mRNA is altered before it leaves the nucleus. - In eukaryotes, the nuclear membrane separates transcription from translation.

Select all of the following that are true about prokaryotic versus eukaryotic gene expression.

- In eukaryotes, the nuclear membrane separates transcription from translation. - In eukaryotes, mRNA is altered before it leaves the nucleus.

Select all of the following that are true with respect to genomes.

- In prokaryotic cells, the genome usually consists of just one circular DNA molecule. -In eukaryotic cells, the genome is usually divided up into multiple chromosomes

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 the statements about nucleotides that are accurate.

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

Select all of the following that are functions of the 5' cap and 3' poly A tail added to mRNA after transcription in eukaryotes.

- protect RNA from degradation - help ribosomes attach to 5' end of mRNA

Select all of the following that are genes.

- sequence of DNA nucleotides that codes for a specific protein - sequence of DNA nucleotides that codes for a specific RNA molecule

Select all of the following that are components of nucleotides.

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

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 ------- , Incorrect Unavailable, and the amount of the nucleotide base cytosine always equals the amount of the nucleotide base -------.

- thymine (t) - guanine (g)

Select all of the following that are actions of the enzyme RNA polymerase.

- unzip the DNA to expose the template strand - build an mRNA chain - attach to the promoter on DNA

In transcription, a(n) ----- molecule is produced from the information that is encoded in a(n) ----- molecule.

-RNA -DNA

Select all of the following that are true about codons.

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

Two strands of DNA within the double helix are said to be complementary to each other because ---- on one strand always pairs with thymine on the opposite strand, and cytosine on one strand always pairs with ------ on the opposite strand.

-adenine -guanine

Select all the locations in a eukaryotic cell where DNA is found.

-chloroplast -nucleus -mitochondrion

Select all of the following that are true about RNA.

-contains the sugar ribose -single-stranded, but can form loops -can act as an enzyme -contains the bases A, U, G, and C

The DNA double ------ , Correct Unavailable resembles a twisted ladder, where each rail of the "ladder" (each backbone) is composed of alternating deoxyribose sugars and -------- , Incorrect Unavailable groups joined together by ------ bonds.

-helix -phosphate -covalent

Select all the functions of ribosomal RNA.

-help align the ribosome with the mRNA to prepare for translation -catalyze the formation of bonds between amino acids in the developing protein

Some eukaryotic organelles, such as ---- and ----, contain their own genomes in addition to the cell's nuclear DNA.

-mitochondria -chloroplast

Select all of the following that describe the nitrogenous bases adenine and guanine.

-purines -double-ring structure

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

Arrange the events of transcription in the order that they occur, beginning with the first event at the top.

1. RNA polymerase binds to the gene's promoter 2. RNA polymerase moves down the DNA template strand, producing a complementary RNA molecule 3. RNA polymerase separates from the DNA and newly synthesized RNA is released

During transcription, RNA polymerase moves along the DNA template strand, adding RNA nucleotides to the growing ______ end of the RNA molecule.

3'

Shortly after transcription in eukaryotic cells, a string of 100-200 adenines is added to the 3' end of the mRNA molecule, producing what is known as a --- tail, and a short sequence of nucleotides called the 5' ---- is added to the 5' end of the mRNA molecule.

A, cap

In the DNA molecule, why does A pair with T and not C?

Both A and T can only form two hydrogen bonds.

Which scientist showed that the amount of the base guanine in a DNA molecule equals the amount of the base cytosine in a DNA molecule?

Chargaff

During transcription, RNA nucleotide bases bind with the exposed complementary bases on the template strand of

DNA

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

DNA

A eukaryotic chromosome consists of

DNA wrapped around histones and other proteins.

During transcription, RNA nucleotide bases bind with the exposed complementary bases on the template strand of

DNA.

Erwin Chargaff

Determined that DNA contains equal amounts of adenine and thymine and of guanine and cytosine

What is one major difference between eukaryotes and prokaryotes with respect to translation?

In prokaryotes, translation can take place even before transcription is complete.

A gene is a sequence of DNA nucleotides that encodes a specific protein or

RNA molecule.

During transcription, what enzyme attaches to the promoter, unzips the DNA double helix, and adds complementary RNA nucleotides?

RNA polymerase

initiation

RNA polymerase binds to the gene's promoter.

elongation

RNA polymerase moves down the template strand, adding nucleotides and producing a complementary RNA molecule.

Termination

RNA polymerase separates from the DNA and the newly synthesized RNA is released.

Maurice Wilkins and Rosalind Franklin

Used X-ray diffraction to determine that DNA has a regular, repeating structure of building blocks

James Watson and Francis Crick

Used the known ratios of nucleotides along with the X-ray diffraction data to build a ball-and-stick model of the DNA double helix

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

Watson and Crick

The ______ pattern generated by Wilkins and Franklin revealed that DNA was comprised of a regular repeating structure of building blocks.

X-ray diffraction

In the base pairs of the DNA double helix,

a double-ring base always pairs with a single-ring base.

Bacterial genomes normally consist of ______ chromosome(s), whereas eukaryotic genomes are normally made up of ______ chromosome(s).

a single circular; multiple linear

The term genome refers to

all the genetic material in an organism's cell.

What describes a ribosome?

an rRNA-protein structure that is the site of translation

Although the two chains of the DNA double helix are parallel to each other, they are oriented in opposite directions. This head-to-tail configuration is referred to as a(n) ______ arrangement.

antiparallel

In eukaryotic cells, the mRNA is altered before it leaves the nucleus. A short sequence of modified nucleotides, known as a ______ is added to the 5' end and a string of adenines called a ______ is added to the 3' end.

cap; poly-A tail

What is a discrete package of DNA and its associated proteins?

chromosome

What are coding regions of eukaryotic mRNA that are translated?

exons

A(n) ______ is a sequence of DNA nucleotides that codes for a specific protein or RNA molecule.

gene

Within the DNA double helix, the nitrogenous bases in base pairs are joined by ______ bonds, which are collectively strong but can also be pulled apart if the cell needs access to the DNA.

hydrogen

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

intron.

When Griffith mixed together live strain R bacteria and heat-killed S bacteria and injected them into mice, the mice died, and ______ bacteria were isolated from the mice, indicating that something could pass between cells and transform them.

live S strain

The type of RNA that carries the information to specify a protein is called

messenger RNA (mRNA).

If the DNA double helix resembles a ladder, the interior "rungs" of the DNA ladder consist of

nitrogenous bases joined by hydrogen bonds.

In the synthesis of RNA from DNA, the enzyme RNA polymerase adds ______ to the ______ end of the growing RNA molecule.

nucleotides; 3 prime

A major difference between eukaryotic and prokaryotic chromosomes is that in eukaryotes, multiple, linear chromosomes are housed within an organelle called the ---- , and each chromosome consists of DNA associated with proteins.

nucleus

A major difference between eukaryotic and prokaryotic chromosomes is that in eukaryotes, multiple, linear chromosomes are housed within an organelle called the -----, and each chromosome consists of DNA associated with proteins.

nucleus

What RNA modification in eukaryotes decreases the chances that the mRNA will be degraded before translation?

poly A tail

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

Messenger RNA carries information that specifies the amino acid sequence of a

protein

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

proteins

RNA differs from DNA chemically because RNA nucleotides contain the sugar ______, and in RNA, the nitrogenous base ______ is substituted for thymine.

ribose; uracil

A complex of rRNA and proteins called a(n) ----- is the physical location of protein synthesis.

ribosome

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

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

---- is a type of RNA that serves as a "connector" between the mRNA codon and a particular amino acid.

tRNA or transfer or Transfer RNA

The DNA strand that is "read" during transcription is called the ______ strand.

template

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

template strand of DNA

Wilkins and Franklin performed X-ray diffraction that revealed details about

the three-dimensional shape of the DNA molecule.

In what process does the cell make a complementary RNA molecule from a DNA sequence?

transcription

What type of RNA binds to an mRNA codon at one end and a specific amino acid at the other end?

transfer RNA (tRNA)

Which of the following best describes transcription?

using a DNA template to synthesize RNA