BIO101 EXAM 3 CH 25

A(n) _____, is a three-nucleotide sequence in mRNA that codes for a particular amino acid.

codon

Erwin Chargaff determined that the number of ____ like guanine and adenine always equal the number of ____ like cytosine and thymine.

purine, pyrimidine

Ribosomes are made of proteins and a type of nucleic acid abbreviated ____ .

rRNA

Why did early molecular geneticists know that the genetic material needed to be a stable molecule? a. So that it could be copied during transcription. b. So it could be replicated accurately. c. So it could be passed from one generation to the next. d. Because it needed to exist at high temperatures.

b. So it could be replicated accurately. c. So it could be passed from one generation to the next.

Select the stages of translation. a. elongation b. initiation c. replication d. ligation e. termination

b. initiation a. elongation e. termination

Select all that apply Which of the following are true of both transcription and translation? a. occur in the nucleus of eukaryotes b. occur in eukaryotes and prokaryotes c. RNA is involved d. stage in gene expression e. involve proteins and nucleic acids f. involve DNA polymerase

b. occur in eukaryotes and prokaryotes c. RNA is involved d. stage in gene expression e. involve proteins and nucleic acids

Select the characteristics of translation. a. occurs in eukaryotic nuclei b. results in a protein product c. involves a mRNA molecule d. involves RNA polymerase

b. results in a protein product c. involves a mRNA molecule

Which of the following are components or structures of a ribosome? a. transfer RNA b. ribosomal RNA c. large subunit d. small subunit e. protein f. DNA

b. ribosomal RNA c. large subunit d. small subunit e. protein

Rosalind Franklin's X-ray diffraction photograph demonstrated that DNA a. was formed from nucleotides. b. was a double helix. c. used a triplet code for storing information. d. contained base pairs. e. contained equal proportions of purines and pyrimidines.

b. was a double helix.

Most cancers begin as an abnormal cell growth or tumor that is referred to as ____ , or not cancerous, and usually does not grow larger.

benign

The phase of translation that allows additional amino acids to be added to the growing polypeptide is called ____ .

elongation

The production and usage of a gene's product is called gene ____ .

expression

Transcription and translation are two stages in the process of gene ____.

expression

The expression of selected _____ accounts for the specialization of cells like white blood cell, muscle fibers, and nerve cells.

genes

A mutation that results in a difference of one base from the original DNA sequence is called a ____ mutation.

point

Each ribosomal subunit is composed of rRNA and many _____ .

proteins

Which RNA molecule is associated most closely with both ribosomes and translation? rRNA tRNA mRNA

rRNA

A codon is composed of ____ nucleotides, also called a triplet.

3

In the 1940s, scientists had concluded that the genetic material was most likely either _____ or ____ .

DNA or proteins

The purpose of mRNA is to carry information from ____ to the ____ .

DNA, ribosome

Highly compacted chromatin, which is not accessible for transcription is called ____.

heterochromatin

The enzyme that is responsible for catalyzing the process of transcription is called ____ _____.

RNA Polymerase

True or false: A purine base normally pairs with a pyrimidine base. True False

True

True or false: All three major types of RNA are produced by transcription of DNA. True False

True

The new synthetic nucleotides have been inserted into the E.coli bacteria to increase the number of ____ ____ they can produce.

amino acids

Which of the following are possible locations where ribosomes serve as sites for protein synthesis in a eukaryotic cell? a. bound to nucleus b. free in cytoplasm c. free in nucleus d. bound to endoplasmic reticulum e. bound to Golgi apparatus

b. free in cytoplasm d. bound to endoplasmic reticulum

The inaccessibility of genes in heterochromatin is an example of _____ control of gene expression. a. transcriptional b. pretranscriptional c. translational d. posttranscriptional

d. pretranscriptional

This nucleic acid molecule is joined with proteins, and is produced in the nucleolus of a nucleus, where a portion of DNA serves as a template for its formation. a. tRNA b. DNA coding strand c. mRNA d. DNA template strand e. rRNA

e. rRNA

Chemical or physical agents that increase the chance of mutation are called _____ .

mutagens

A gene _____ is a permanent change to the base sequence of DNA.

mutation

DNA is composed of units called _____, each of which contains a phosphate group, a 5-carbon sugar, and one of 4 nitrogen-containing bases.

nucleotides

A cluster of genes that codes for proteins related to a particular metabolic pathway is called a(n) _____.

operon

The production of two DNA copies from a single original DNA molecule is called DNA _____ .

replication

The codon near which the small ribosomal subunit attaches to the mRNA molecule to be translated, which codes for methionine (AUG) is called the ____ codon.

start

The specific type of nucleic acid bearing anticodons for the amino acid sequence is abbreviated _____ .

tRNA

Molecules of mRNA, tRNA, and rRNA are produced by the process of ______.

transcription

The process by which an RNA strand is synthesized from a DNA template strand is called ____ .

transcription

Which of the following are components of a nucleotide? a. Phosphate b. Lipid and a protein c. 5-carbon sugar d. Nitrogen-containing base

a. Phosphate c. 5-carbon sugar d. Nitrogen-containing base

Which scientist's X-ray diffraction data helped to demonstrate the double helix structure of DNA? a. Rosalind Franklin b. James Watson c. Erwin Chargaff d. Francis Crick

a. Rosalind Franklin

Select the characteristics that researchers suspected the genetic material would have prior to the discovery that the genetic material was DNA. a. accurate replication b. uses a triplet code c. ability to store information d. passes from one generation to the next e. comprised of nucleotides

a. accurate replication c. ability to store information d. passes from one generation to the next

Select the choices that describe mutagens. a. are environmental factors b. can be physical, like radiation, or chemical c. are passed from one generation to the next d. cause changes in DNA base sequences

a. are environmental factors b. can be physical, like radiation, or chemical d. cause changes in DNA base sequences

Protein synthesis (translation) occurs at which of the following locations within eukaryotic cells? (Select all that apply) a. cytoplasm b. phospholipid bilayer c. Golgi apparatus d. nuclei e. rough endoplasmic reticulum

a. cytoplasm e. rough endoplasmic reticulum

Select the items that play a part in initiation of translation. a. initiator tRNA b. small ribosomal subunit c. large ribosomal subunit d. template DNA strand e. messenger RNA

a. initiator tRNA b. small ribosomal subunit c. large ribosomal subunit e. messenger RNA

A primary difference between control of gene expression in prokaryotes and eukaryotes a. is that prokaryotes have fewer promoters than they have genes. b. is that prokaryotes express all of their genes at all times while eukaryotes do not. c. is that they use different sets of amino acids to build proteins. d. is that they employ different genetic codes.

a. is that prokaryotes have fewer promoters than they have genes.

Select the items that play a part in translational initiation. a. mRNA b. rRNA c. release factors d. stop codon e. start codon

a. mRNA b. rRNA e. start codon

Which of the following are true of transcription but not translation? a. occurs in eukaryotic nuclei b. involves tRNA molecules and amino acids c. results in a protein product d. involves RNA polymerase

a. occurs in eukaryotic nuclei b. involves RNA polymerase

Select the levels of control of gene expression. a. posttranscriptional b. translational c. posttranslational d. pretranslational e. transcriptional f. pretranscriptional g. replicational

a. posttranscriptional b. translational c. posttranslational e. transcriptional f. pretranscriptional

Select the findings of Erwin Chargaff regarding DNA composition. a. pyrimidines = purines b. G = A c. A = T d. G=C e. C = T

a. pyrimidines = purines c. A = T d. G=C

Select the characteristics of translation. a. results in a protein product b. involves a mRNA molecule c. involves RNA polymerase d. occurs in eukaryotic nuclei

a. results in a protein product c. involves a mRNA molecule

Select the items that play a part in initiation of translation. a. small ribosomal subunit b. template DNA strand c. large ribosomal subunit d. messenger RNA e. initiator tRNA

a. small ribosomal subunit c. large ribosomal subunit d. messenger RNA e. initiator tRNA

Which nucleic acid is the physical carrier of individual amino acids? a. tRNA b. DNA coding strand c. DNA template strand d. mRNA e. rRNA

a. tRNA mRNA is for protein synthesis

During initiation, a. the ribosomal subunits assemble. b. the polypeptide is released from the ribosome. c. the DNA unwinds and unzips. d. amino acids are brought to the ribosome sequentially.

a. the ribosomal subunits assemble.

The synthesis of new DNA double helix molecules from a pre-existing parent molecule is called _______. a. translation b. transcription c. DNA replication d. DNA genesis

c. DNA replication

What is the name of the enzyme complex responsible for synthesizing a new RNA molecule through nucleotide binding? a. DNA polymerase b. RNA reductase c. RNA polymerase d. DNA reductase

c. RNA polymerase

Which of the following are the two new nucleotides that have been created by the company Synthorx? a. Z b. H c. X d. Y

c. X d. Y

During elongation, a. the DNA unwinds and unzips. b. the polypeptide is released from the ribosome. c. amino acids are brought to the ribosome sequentially. d. the ribosomal subunits assemble.

c. amino acids are brought to the ribosome sequentially.

Genes that are active in most of the body's cell are called _____ genes. a. generalist b. regulatory c. housekeeping d. homeostatic

c. housekeeping

Which structure carries genetic information from the DNA to the ribosome? a. DNA b. tRNA c. mRNA d. rRNA

c. mRNA

A mutation that results in one base in the DNA being replaced by a different base is called a a. frameshift mutation. b. somatic mutation. c. point mutation. d. germ-line mutation.

c. point mutation.

Anticodons are found on which nucleic acid? a. DNA coding strand b. rRNA c. tRNA d. mRNA e. DNA template strand

c. tRNA

The production of mRNA from a DNA template occurs during a. replication. b. translation. c. transcription. d. termination.

c. transcription.