Biology 425: True-False Questions- Chapters 8-25
1. Sexual Reproduction; p. 141; easy; ans: F
All eukaryotes ( do not) reproduce sexually.
2. Sexual Reproduction; p. 142; easy; ans: T
Homologous chromosomes resemble each other in size, shape, and the kinds of hereditary
information they contain.
3. The Eukaryotic Chromosome; p. 143; moderate; ans: F
A nucleosome is composed of histone proteins wrapped (twice) around a DNA filament.
4. The Process of Meiosis; pp. 143-144; easy; ans: T
In contrast to a gamete, a spore can develop into an organism without uniting with another cell.
5. The Process of Meiosis; p. 145; moderate; ans: F
Crossing-over is the exchange of genetic material between the sister (homologous) chromatids of
a chromosome.
6. The Process of Meiosis; p. 145; moderate; ans: T
Chiasmata are the visible representation that crossing-over has taken place.
7. The Process of Meiosis; p. 147; moderate; ans: F
It is (impossible) likely that one of the four daughter cells resulting from meiosis will be
genetically identical to one of the gametes that fused to produce the diploid line of cells
undergoing meiosis.
8. How Characteristics Are Inherited; p. 150; moderate; ans: F
The term “genotype” (phenotype) refers to the appearance of an individual.
9. How Characteristics Are Inherited; p. 151; moderate; ans: T
A testcross is used to determine whether a plant showing a dominant trait is homozygous or
heterozygous for that trait.
10. The Principle of Independent Assortment; pp. 151–152; moderate; ans: T
Mendel’s experiments using dihybrid crosses produced completely new combinations of
characteristics in the F1 generation.
11. Linkage; p. 152; easy; ans: F
The greater the distance between two genes on a chromosome, the smaller (greater) is the chance
that they will undergo crossing-over during meiosis.
12. Mutations; p. 153; easy; ans: T
A mutation is any change in the hereditary state of an organism.
13. Mutations; p. 154; easy; ans: T
,Polyploidy results from the duplication of whole sets of chromosomes.
14. Mutations; p. 155; moderate; ans: T
A mutation in a haploid cell is more likely to have an effect on phenotype than a mutation in a
diploid cell.
15. Broadening the Concept of the Gene; p. 156; moderate; ans: F
Epistasis (Polygenic inheritance) is an example of interactions between the alleles of a gene.
16. Broadening the Concept of the Gene; p. 157; moderate; ans: T
Cytoplasmic inheritance refers to genes located in mitochondria or plastids.
17. Broadening the Concept of the Gene; p. 157; easy; ans: F
The genotype (phenotype) is the result of the phenotype (genotype) interacting with the
environment.
18. Asexual Reproduction: An Alternative Strategy; p. 158; easy; ans: T
Plants that reproduce only asexually have evolved from ancestors that were capable of sexual
reproduction.
19. Advantages of Sexual Reproduction; p. 159; moderate; ans: T
In theory, sexual reproduction is unnecessary for the survival of a population of organisms in an
unchanging environment.
True-False Questions
1. The Structure of DNA; p. 163; moderate; ans: F
In the ladder molecule of a DNA molecule, the purine and pyrimidine bases comprise the (rungs)
sides of the ladder.
2. The Structure of DNA; p. 165; easy; ans: T
Adenine forms two hydrogen bonds with thymine.
3. The Structure of DNA; p. 166; moderate; ans: T
The complementarity of the two strands of DNA is a direct result of A pairing only with T and C
pairing only with G.
4. The Structure of DNA; p. 166; moderate; ans: F
The two strands of a DNA molecule are said to be antiparallel, each strand having its 5 end at
the same (opposite) end of the molecule.
5. DNA Replication; p. 166; easy; ans: T
In DNA replication, each strand serves as a template for the formation of a new strand.
6. DNA Replication; p. 167; moderate; ans: T
DNA polymerase synthesizes new DNA strands only in the 5 to 3 direction.
, 7. DNA Replication; p. 167; moderate; ans: F
In DNA replication, the leading (lagging) strand is synthesized in fragments, called Okazaki
fragments, while the lagging (leading) strand is synthesized continuously.
8. From DNA to Protein: The Role of RNA; p. 168; easy; ans: F
RNA contains thymine (uracil) instead of uracil (thymine).
9. From DNA to Protein: The Role of RNA; p. 168; easy; ans: T
Transcription is catalyzed by the enzyme RNA polymerase.
10. The Genetic Code; p. 169; moderate; ans: T
The triplet codon was first demonstrated in experiments using bacterial extracts, mRNAs, and
radioactively labeled amino acids.
11. The Genetic Code; p. 169; moderate; ans: T
Some amino acids have more than one codon.
12. The Genetic Code; p. 169; easy; ans: F
The genetic code in prokaryotes is different from that (virtually the same) in eukaryotic cells.
13. Protein Synthesis; p. 170; easy; ans: F
The terminator is a section of DNA that codes for the destruction of mRNA molecules (RNA
polymerase) following (transcription) translation.
14. Protein Synthesis; p. 171; moderate; ans: T
In the initiation phase of translation, the larger ribosomal subunit attaches to the smaller subunit.
15. Protein Synthesis; p. 173; easy; ans: T
A group of ribosomes translating the same mRNA molecule is called a polysome.
16. Protein Synthesis; p. 173; easy; ans: F
Release factors are directly involved in the (termination) elongation phase of translation.
17. Protein Synthesis; p. 173; moderate; ans: F
Proteins destined for the nucleus are taken up through the nuclear envelope by (posttranslational)
cotranslational import.
18. Regulation of Gene Expression in Eukaryotes; p. 175; easy; ans: T
In the cells of a multicellular eukaryote, some genes are active at the same time that others are
inactive.
19. Regulating Gene Expression; p. 175; moderate; ans: T
In a plant, root cells have the same genetic composition as leaf cells.
1. Sexual Reproduction; p. 141; easy; ans: F
All eukaryotes ( do not) reproduce sexually.
2. Sexual Reproduction; p. 142; easy; ans: T
Homologous chromosomes resemble each other in size, shape, and the kinds of hereditary
information they contain.
3. The Eukaryotic Chromosome; p. 143; moderate; ans: F
A nucleosome is composed of histone proteins wrapped (twice) around a DNA filament.
4. The Process of Meiosis; pp. 143-144; easy; ans: T
In contrast to a gamete, a spore can develop into an organism without uniting with another cell.
5. The Process of Meiosis; p. 145; moderate; ans: F
Crossing-over is the exchange of genetic material between the sister (homologous) chromatids of
a chromosome.
6. The Process of Meiosis; p. 145; moderate; ans: T
Chiasmata are the visible representation that crossing-over has taken place.
7. The Process of Meiosis; p. 147; moderate; ans: F
It is (impossible) likely that one of the four daughter cells resulting from meiosis will be
genetically identical to one of the gametes that fused to produce the diploid line of cells
undergoing meiosis.
8. How Characteristics Are Inherited; p. 150; moderate; ans: F
The term “genotype” (phenotype) refers to the appearance of an individual.
9. How Characteristics Are Inherited; p. 151; moderate; ans: T
A testcross is used to determine whether a plant showing a dominant trait is homozygous or
heterozygous for that trait.
10. The Principle of Independent Assortment; pp. 151–152; moderate; ans: T
Mendel’s experiments using dihybrid crosses produced completely new combinations of
characteristics in the F1 generation.
11. Linkage; p. 152; easy; ans: F
The greater the distance between two genes on a chromosome, the smaller (greater) is the chance
that they will undergo crossing-over during meiosis.
12. Mutations; p. 153; easy; ans: T
A mutation is any change in the hereditary state of an organism.
13. Mutations; p. 154; easy; ans: T
,Polyploidy results from the duplication of whole sets of chromosomes.
14. Mutations; p. 155; moderate; ans: T
A mutation in a haploid cell is more likely to have an effect on phenotype than a mutation in a
diploid cell.
15. Broadening the Concept of the Gene; p. 156; moderate; ans: F
Epistasis (Polygenic inheritance) is an example of interactions between the alleles of a gene.
16. Broadening the Concept of the Gene; p. 157; moderate; ans: T
Cytoplasmic inheritance refers to genes located in mitochondria or plastids.
17. Broadening the Concept of the Gene; p. 157; easy; ans: F
The genotype (phenotype) is the result of the phenotype (genotype) interacting with the
environment.
18. Asexual Reproduction: An Alternative Strategy; p. 158; easy; ans: T
Plants that reproduce only asexually have evolved from ancestors that were capable of sexual
reproduction.
19. Advantages of Sexual Reproduction; p. 159; moderate; ans: T
In theory, sexual reproduction is unnecessary for the survival of a population of organisms in an
unchanging environment.
True-False Questions
1. The Structure of DNA; p. 163; moderate; ans: F
In the ladder molecule of a DNA molecule, the purine and pyrimidine bases comprise the (rungs)
sides of the ladder.
2. The Structure of DNA; p. 165; easy; ans: T
Adenine forms two hydrogen bonds with thymine.
3. The Structure of DNA; p. 166; moderate; ans: T
The complementarity of the two strands of DNA is a direct result of A pairing only with T and C
pairing only with G.
4. The Structure of DNA; p. 166; moderate; ans: F
The two strands of a DNA molecule are said to be antiparallel, each strand having its 5 end at
the same (opposite) end of the molecule.
5. DNA Replication; p. 166; easy; ans: T
In DNA replication, each strand serves as a template for the formation of a new strand.
6. DNA Replication; p. 167; moderate; ans: T
DNA polymerase synthesizes new DNA strands only in the 5 to 3 direction.
, 7. DNA Replication; p. 167; moderate; ans: F
In DNA replication, the leading (lagging) strand is synthesized in fragments, called Okazaki
fragments, while the lagging (leading) strand is synthesized continuously.
8. From DNA to Protein: The Role of RNA; p. 168; easy; ans: F
RNA contains thymine (uracil) instead of uracil (thymine).
9. From DNA to Protein: The Role of RNA; p. 168; easy; ans: T
Transcription is catalyzed by the enzyme RNA polymerase.
10. The Genetic Code; p. 169; moderate; ans: T
The triplet codon was first demonstrated in experiments using bacterial extracts, mRNAs, and
radioactively labeled amino acids.
11. The Genetic Code; p. 169; moderate; ans: T
Some amino acids have more than one codon.
12. The Genetic Code; p. 169; easy; ans: F
The genetic code in prokaryotes is different from that (virtually the same) in eukaryotic cells.
13. Protein Synthesis; p. 170; easy; ans: F
The terminator is a section of DNA that codes for the destruction of mRNA molecules (RNA
polymerase) following (transcription) translation.
14. Protein Synthesis; p. 171; moderate; ans: T
In the initiation phase of translation, the larger ribosomal subunit attaches to the smaller subunit.
15. Protein Synthesis; p. 173; easy; ans: T
A group of ribosomes translating the same mRNA molecule is called a polysome.
16. Protein Synthesis; p. 173; easy; ans: F
Release factors are directly involved in the (termination) elongation phase of translation.
17. Protein Synthesis; p. 173; moderate; ans: F
Proteins destined for the nucleus are taken up through the nuclear envelope by (posttranslational)
cotranslational import.
18. Regulation of Gene Expression in Eukaryotes; p. 175; easy; ans: T
In the cells of a multicellular eukaryote, some genes are active at the same time that others are
inactive.
19. Regulating Gene Expression; p. 175; moderate; ans: T
In a plant, root cells have the same genetic composition as leaf cells.
