1
The condition resulting from a trisomy of chromosome 21 is
Down syndrome
During transcription, the synthesis of the mRNA strand proceeds in which direction?
5' to 3' only
Complementary base-pairing allows for
A) genes to be expressed as phenotype.
B) spontaneous mutations to occur.
C) covalent bonds to form between the opposite bases.
D) replication to be semiconservative.
E) DNA to serve as its own template for replication.
E) DNA to serve as its own template for replication.
The C value is the amount of DNA in a
A) diploid genome.
B) cell's nucleus.
C) eukaryotic genome.
D) bacterial genome.
E) haploid genome.
E) haploid genome.
What signals the termination of translation?
A) The ribosome reaches the end of the mRNA.
B) The polypeptide chain folds into a protein.
C) The ribosome reaches a start codon.
D) The ribosome reaches a stop codon.
E) The ribosome runs out of charged tRNAs.
D) The ribosome reaches a stop codon.
The process by which genetic information is transferred from DNA to RNA is called
transcription
Why is it that a carrot plant can express a bacterial gene?
A) Because the bacterial gene hijacks the carrot's cellular machinery
B) Because the genetic code is the same in both organisms
C) Because of the wobble phenomenon
D) Because of the degeneracy of the genetic code
E) A carrot cannot express a bacterial gene.
B) Because the genetic code is the same in both organisms
After a region of DNA has been replicated, ______ removes the RNA primers.
DNA polymerase I
A peptide bond forms between the ________ of one amino acid and the ________ of another.
A) amino group, phosphate group
B) carboxyl group, sulfide group
C) R group, R group
D) amino group, carboxyl group
E) amino group, R group
D) amino group, carboxyl group
Which genetic disease(s) are caused by defective proteins that are not enzymes?
Sickle-cell anemia and cystic fibrosis
A person with sickle-cell trait has ________ at the beta-globin locus.
A) one mutant and one deleted allele
B) one wild-type and one deleted allele
C) two wild-type alleles
D) two mutant alleles
E) one wild-type and one mutant allele
E) one wild-type and one mutant allele
What is a replication bubble?
A) A DNA sequence that initiates replication
B) A locally denatured segment of DNA where replication originates
C) A tangle of denatured DNA strands near the replication fork
D) A localized site in the nucleus where chromosomes are replicating
E) A complex of replication enzymes on the DNA template strand
B) A locally denatured segment of DNA where replication originates
During replication, the direction of synthesis of new DNA from the leading and lagging strands is
5' to 3' only.
As helicase unwinds the DNA molecule, what keeps the strands apart?
Single-strand binding proteins
Self-cleaving RNAs that function catalytically are called
ribozymes
In eukaryotes, where does transcription take place?
In the nucleus
The sequence of bases of a molecule of mRNA is converted into a corresponding amino acid sequence during
translation
How many replication forks are produced when DNA denatures at an origin?
2
What does a gene actually code for?
A polypeptide
What is the basic shape of a tRNA molecule?
A three-dimensional cloverleaf
In eukaryotes, chromosomes are duplicated during which stage of the cell cycle?
S
A monosomic cell would produce gametes with how many chromosomes?
A) N and N-1
B) N-1
C) N and N+1
D) N+1
E) N
N and N-1
Which enzyme elongates the new DNA strand starting at an RNA primer?
DNA polymerase III
During the initiation step of transcription, what molecule binds the promoter region of a DNA molecule?
RNA polymerase
The single strand of mRNA that is produced during transcription has the same polarity as the ________ strand of
DNA.
nontemplate