Question 1

A ribosome consists of ______ and ______.

Accepted Answer

A) DNA; mRNA 
B) mRNA; protein 
C) mRNA; tRNA 
D) rRNA; mRNA 
E) rRNA; protein 
A) DNA; mRNA 
B) mRNA; protein 
C) mRNA; tRNA 
D) rRNA; mRNA 
E) rRNA; protein

Question 2

The complementarity of the two strands of DNA is a direct result of A pairing only with T and C pairing only with G.

Accepted Answer

A) True 
 B)False

Question 3

In the ladder analogy of DNA structure, the sides of the ladder are composed of:

Accepted Answer

A) sugars. 
B) phosphates. 
C) alternating sugars and phosphates. 
D) alternating sugars and nitrogenous bases. 
E) nitrogenous bases. 
A) sugars. 
B) phosphates. 
C) alternating sugars and phosphates. 
D) alternating sugars and nitrogenous bases. 
E) nitrogenous bases.

Question 4

Which of the following statements about DNA replication in eukaryotes is FALSE?

Accepted Answer

A) It is a bidirectional process. 
B) Helicases break the hydrogen bonds at the origin of replication. 
C) DNA polymerases catalyze the synthesis of the new strands. 
D) The two replication forks move in opposite directions away from the origin. 
E) There is only one origin of replication. 
A) It is a bidirectional process. 
B) Helicases break the hydrogen bonds at the origin of replication. 
C) DNA polymerases catalyze the synthesis of the new strands. 
D) The two replication forks move in opposite directions away from the origin. 
E) There is only one origin of replication.

Question 5

Which of the following is the best estimate for the percentage of DNA in eukaryotic cells that codes for proteins?

Accepted Answer

A) less than 1 percent 
B) less than 10 percent 
C) about 25 percent 
D) about 50 percent 
E) about 75 percent 
A) less than 1 percent 
B) less than 10 percent 
C) about 25 percent 
D) about 50 percent 
E) about 75 percent

Question 6

The two major categories of repeated DNA are tandemly repeated DNA and interspersed repeated DNA.

Accepted Answer

A) True 
 B)False

Question 7

Histone acetylation neutralizes the histone tails, and consequently transcription is repressed.

Accepted Answer

A) True 
 B)False

Question 8

Which of the following events occurs in eukaryotic cells but NOT in prokaryotic cells?

Accepted Answer

A) RNA polymerase attaches to a particular nucleotide sequence on the DNA. 
B) RNA is synthesized using the 3′ to 5′ DNA strand as a template. 
C) Two or more structural genes are transcribed onto a single RNA molecule. 
D) mRNA transcripts are extensively modified before they leave the nucleus. 
E) tRNAs, rRNAs, and mRNAs are all involved in the translation process. 
A) RNA polymerase attaches to a particular nucleotide sequence on the DNA. 
B) RNA is synthesized using the 3′ to 5′ DNA strand as a template. 
C) Two or more structural genes are transcribed onto a single RNA molecule. 
D) mRNA transcripts are extensively modified before they leave the nucleus. 
E) tRNAs, rRNAs, and mRNAs are all involved in the translation process.

Question 9

Interspersed repeated DNA units:

Accepted Answer

A) are arranged in tandem. 
B) tend to be smaller than 10 base pairs long. 
C) constitute less than 10 percent of the DNA of most multicellular organisms. 
D) are identical to one another. 
E) are believed to have originated from transposons. 
A) are arranged in tandem. 
B) tend to be smaller than 10 base pairs long. 
C) constitute less than 10 percent of the DNA of most multicellular organisms. 
D) are identical to one another. 
E) are believed to have originated from transposons.

Question 10

In DNA replication, _______ catalyzes the joining of Okazaki fragments.

Accepted Answer

A) single-strand binding protein 
B) DNA ligase 
C) histone 
D) DNA polymerase 
E) helicase 
A) single-strand binding protein 
B) DNA ligase 
C) histone 
D) DNA polymerase 
E) helicase

Question 11

Which of the following are complementary bases?

Accepted Answer

A) adenine and cytosine 
B) adenine and guanine 
C) thymine and cytosine 
D) guanine and cytosine 
E) thymine and guanine 
A) adenine and cytosine 
B) adenine and guanine 
C) thymine and cytosine 
D) guanine and cytosine 
E) thymine and guanine

Question 12

Most eukaryotic structural genes contain introns.

Accepted Answer

A) True 
 B)False

Question 13

An incoming aminoacyl-tRNA molecule binds to the ribosome at the ______ site.

Accepted Answer

A) A (aminoacyl) 
B) mRNA-binding 
C) P (peptidyl) 
D) E (exit) 
E) promoter 
A) A (aminoacyl) 
B) mRNA-binding 
C) P (peptidyl) 
D) E (exit) 
E) promoter

Question 14

A codon consists of _____ nucleotides in a(n) ____ molecule.

Accepted Answer

A) two; DNA 
B) three; DNA 
C) four; DNA 
D) three; RNA 
E) four; RNA 
A) two; DNA 
B) three; DNA 
C) four; DNA 
D) three; RNA 
E) four; RNA

Question 15

Heterochromatin is more tightly condensed than euchromatin and in some regions is never transcribed.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following molecules contains an anticodon?

Accepted Answer

A) DNA 
B) mRNA 
C) tRNA 
D) rRNA 
E) protein 
A) DNA 
B) mRNA 
C) tRNA 
D) rRNA 
E) protein

Question 17

Exons are segments of a gene that:

Accepted Answer

A) are transcribed into segments of mRNA that are snipped out before translation. 
B) occur in prokaryotic but not eukaryotic chromosomes. 
C) consist of RNA rather than DNA nucleotides. 
D) are not transcribed by RNA polymerase. 
E) are translated into protein. 
A) are transcribed into segments of mRNA that are snipped out before translation. 
B) occur in prokaryotic but not eukaryotic chromosomes. 
C) consist of RNA rather than DNA nucleotides. 
D) are not transcribed by RNA polymerase. 
E) are translated into protein.

Question 18

Acetyltransferases catalyze the attachment of acetyl groups to:

Accepted Answer

A) DNA. 
B) ribosomes. 
C) histones. 
D) mRNA. 
E) tRNA. 
A) DNA. 
B) ribosomes. 
C) histones. 
D) mRNA. 
E) tRNA.

Question 19

The most abundant interspersed repeat sequences are transposons.

Accepted Answer

A) True 
 B)False

Question 20

Which of the following events is NOT involved in mRNA processing?

Accepted Answer

A) the addition of a 5′ "cap" 
B) the addition of a poly-A tail 
C) the forming of peptide bonds 
D) the splicing together of exons 
E) the removal of introns 
A) the addition of a 5′ "cap" 
B) the addition of a poly-A tail 
C) the forming of peptide bonds 
D) the splicing together of exons 
E) the removal of introns

Exam 9: The Chemistry of Heredity and Gene Expression

A ribosome consists of ______ and ______.

The complementarity of the two strands of DNA is a direct result of A pairing only with T and C pairing only with G.

In the ladder analogy of DNA structure, the sides of the ladder are composed of:

Which of the following statements about DNA replication in eukaryotes is FALSE?

Which of the following is the best estimate for the percentage of DNA in eukaryotic cells that codes for proteins?

The two major categories of repeated DNA are tandemly repeated DNA and interspersed repeated DNA.

Histone acetylation neutralizes the histone tails, and consequently transcription is repressed.

Which of the following events occurs in eukaryotic cells but NOT in prokaryotic cells?

Interspersed repeated DNA units:

In DNA replication, _______ catalyzes the joining of Okazaki fragments.

Which of the following are complementary bases?

Most eukaryotic structural genes contain introns.

An incoming aminoacyl-tRNA molecule binds to the ribosome at the ______ site.

A codon consists of _____ nucleotides in a(n) ____ molecule.

Heterochromatin is more tightly condensed than euchromatin and in some regions is never transcribed.

Which of the following molecules contains an anticodon?

Exons are segments of a gene that:

Acetyltransferases catalyze the attachment of acetyl groups to:

The most abundant interspersed repeat sequences are transposons.

Which of the following events is NOT involved in mRNA processing?

Botany: an Introduction

The Molecular Composition of Plant Cells

The Plant Cell and the Cell Cycle

The Movement of Substances Into and Out of Cells

The Flow of Energy

Respiration

Photosynthesis, Light, and Life

Sexual Reproduction and Heredity

Recombinant Dna Technology, Plant Biotechnology, and Genomics

The Process of Evolution

Systematics: the Science of Biological Diversity

Prokaryotes and Viruses

Fungi

Protists: Algae and Heterotrophic Protists

Bryophytes

Seedless Vascular Plants

Gymnosperms

Introduction to the Angiosperms

Evolution of the Angiosperms

Plants and People

Early Development of the Plant Body

Cells and Tissues of the Plant Body

The Root: Structure and Development

The Shoot: Primary Structure and Development

Secondary Growth in Stems

Regulating Growth and Development: the Plant Hormones

External Factors and Plant Growth

Plant Nutrition and Soils

The Movement of Water and Solutes in Plants

The Dynamics of Communities and Ecosystems

Global Ecology

Filters

A ribosome consists of and .

A codon consists of _ nucleotides in a(n) molecule.