Deck 47: Principles of Molecular Biology

Question 1

During replication,the addition of bases occurs:

A) in the 5' to 3' direction.
B) in the 3' to 5' direction.
C) in both the 5' to 3' and 3' to 5' direction.
D) only at the methylated end of a DNA strand.

Answer 1

in the 5' to 3' direction.

Question 2

The main goal of the ENCODE Project is to:

A) identify all functional elements within the human genome.
B) catalog and interpret genome-wide DNA methylation patterns.
C) decipher the 3 billion base pairs that make up the human genome.
D) study heritable variations across the human genome.

Answer 2

identify all functional elements within the human genome.

Question 3

In regard to replication,the "parent" strand of deoxyribonucleic acid (DNA):

A) is completely excised by exonuclease enzymes when replication of the strand is complete.
B) has a sequence that is complementary (opposite)to the daughter strand being replicated.
C) is also referred to as the "leading" strand.
D) will be copied by DNA polymerase I to form a new daughter DNA strand.

Answer 3

has a sequence that is complementary (opposite)to the daughter strand being replicated.

Question 4

A woman inherits a specific allele from her mother and develops a specific disease syndrome.Another woman receives the same specific allele from her father and develops a much milder form of the disease.This is likely an example of:

A) genometastisis.
B) genomic imprinting.
C) histone deacetylation.
D) mitochondrial mutation.

Question 5

Transfer RNA (tRNA):

A) contains the anticodon region that binds to mRNA codon in the ribosome.
B) is a macromolecular complex containing ribosomal RNA.
C) contains the codon sequence that synthesizes an amino acid.
D) is a noncoding RNA.

Question 6

In regard to DNA,an exon is defined as a:

A) segment of DNA that is represented in a mature strand of mRNA and is translated into protein.
B) sequence of nucleotides recognized by RNA polymerase as the initiation point of transcription.
C) segment of DNA that is transcribed but removed from mRNA by excision and is not translated into protein.
D) sequence of three base pairs that signal initiation or termination of replication.

Question 7

The expressed function or biological effect of a gene product is termed a:

A) genotype.
B) promoter.
C) codon.
D) phenotype.

Question 8

DNA and RNA differ,in part,because of their sugar molecules.What is missing on the DNA sugar that is present on the RNA sugar?

A) Phosphate group
B) Hydrogen
C) Hydroxyl group
D) Methyl group

Question 9

If 30% of the nucleotides in a genome are A (adenine),what would be the percentage of nucleotides that are G (guanine)?

A) 20%
B) 30%
C) 40%
D) 60%

Question 10

The most basic level of chromatin organization that is present as repeated units along the full length of each chromosome is represented by the:

A) histone.
B) nucleosome.
C) purine.
D) spliceosome.

Question 11

Which one of the following sequences contains a signal that indicates the end of a protein?

A) 5' GUG ACU AGG UGG CGA CCC UAU 3'
B) 5' AAC CGA CUC AUC CAG GUA UAA 3'
C) 5' ACC CGA CCA UCC AGG CUG AGG 3'
D) 5' AGC CGA CUC AUC AGG UUU GAU 3'

Question 12

In regard to transcription,an example of a core promoter sequence on a DNA strand is the TATA box.Core promoters are:

A) codons that signal specific enzymes to terminate replication.
B) segments of DNA that are represented in mature RNA and are translated into protein.
C) sequences of nucleotides that are recognized by RNA polymerase II and that control the initiation of transcription.
D) codons that signal the initiation of replication.

Question 13

Which one of the following statements concerning mitochondrial DNA (mtDNA)is incorrect?

A) Pseudogenes are DNA segments that share significant homology with mtDNA.
B) mtDNA is circular and contains approximately 16,500 base pairs.
C) mtDNA is transmitted by maternal inheritance.
D) The mutation rate of mtDNA is 20 times lower than that of nuclear DNA.

Question 14

In regard to the components of the genetic code,a "codon" is a:

A) sequence of nucleotides that codes for a protein.
B) polymeric molecule composed of nucleic acids.
C) phosphate group,a ribose sugar,and nitrogen.
D) sequence of three nucleotides.

Question 15

The protective nucleotide sequences that are located on the end of a chromosome and make up part of constitutive heterochromatin is referred to as the:

A) centromere.
B) nucleosome
C) acromere.
D) telomere.

Question 16

DNA methylation as a means of regulating gene expression is restricted to which of the following bases?

A) Guanine bases in the dinucleotide sequence GC
B) Cytosine bases in the base pair CG
C) Cytosine bases in the dinucleotide sequence CG
D) Guanine bases in the base pair GC

Question 17

DNA replication is referred to as semiconservative because:

A) only some DNA sequences are duplicated during the cell cycle.
B) certain amino acids can be synthesized by more than one codon.
C) newly duplicated DNA molecules are composed of one parent and one daughter strand.
D) it can only occur in the 5' to 3' direction.

Question 18

A noncoding RNA is one that:

A) is involved in the synthesis of protein by acting as an intermediate.
B) encodes for amino acids only.
C) has a biological function but does not code for a protein.
D) contains an anticodon.

Question 19

The conversion of mRNA nucleotide sequences and the tRNA-attached amino acids into a polypeptide is referred to as:

A) replication.
B) transcription.
C) translation.
D) restriction.

Question 20

Which one of the following statements concerning the difference between DNA and RNA is correct?

A) The four nucleotide building blocks of RNA include thymosin,cytosine,guanine,and adenine.
B) RNA exists typically as a single-stranded polymer that is much shorter than DNA.
C) DNA is composed of a sugar unit,ribose,with an added hydroxyl group at the 2' position.
D) DNA molecules can interact to form complex tertiary structures related to the novel functions of DNA.

Question 21

Regarding transcription,the proteins that help to position eukaryotic RNA polymerase II at the core promoter region are referred to as:

A) activators.
B) elongation factors.
C) general transcription factors.
D) site-specific positioning proteins.

Question 22

In regard to DNA structure,a sugar/phosphate group with its attached base is referred to as a(n):

A) base pair.
B) codon.
C) anticodon.
D) nucleotide.

Question 23

The proteins that wrap DNA tightly to condense it into nucleosomes are called:

A) histones.
B) hormones.
C) lysosomes.
D) nucleotides.

Question 24

The conversion of an mRNA sequence into a string of covalently bonded amino acids is a process referred to as:

A) translation.
B) transcription.
C) redundancy.
D) promotion.

Question 25

In regard to excision of introns and splicing of exons in a primary RNA transcript,the spliceosome is made up of:

A) noncoding RNAs.
B) small nuclear ribonucleoprotein particles.
C) histone proteins and DNA.
D) ribosomal RNA.