Quiz about Genetics
(For High Study)
1. What is the role of messenger RNA (mRNA) in the cell?
● A) It carries amino acids to ribosomes for protein synthesis.
● B) It carries genetic information from DNA to ribosomes.
● C) It helps fold proteins into their functional forms.
● D) It synthesizes DNA from an RNA template.
Answer: B) It carries genetic information from DNA to ribosomes.
Explanation: mRNA is transcribed from DNA in the nucleus and then carries the code to
ribosomes in the cytoplasm, which directs protein synthesis.
2. Which of the following best describes a gene?
● A) A molecule that stores cellular energy.
● B) A segment of DNA that codes for a protein or RNA.
● C) A molecule that transports oxygen in the bloodstream.
● D) The structure where proteins are assembled.
Answer: B) A segment of DNA that codes for a protein or RNA.
Explanation: A gene is a specific sequence of DNA that contains the instructions to make a
functional product, either a protein or a form of RNA.
3. Which of these is NOT an example of a mutation?
● A) Substitution of one base for another in a DNA sequence.
● B) Deletion of a segment of DNA.
● C) Duplication of a chromosome segment.
● D) Transcription of mRNA from DNA.
Answer: D) Transcription of mRNA from DNA.
Explanation: Transcription is a normal process that converts DNA into mRNA. Mutations
involve changes in the DNA sequence, such as substitutions, deletions, or duplications.
, 4. In Mendelian genetics, what ratio of phenotypes would you expect from a monohybrid
cross between two heterozygous parents (Aa x Aa)?
● A) 1:1
● B) 1:2:1
● C) 3:1
● D) 9:3:3:1
Answer: C) 3:1
Explanation: In a monohybrid cross between two heterozygous parents, the offspring
phenotypes will show a 3:1 ratio, where three display the dominant phenotype and one display
the recessive phenotype.
5. Which enzyme is responsible for unwinding the DNA helix during DNA replication?
● A) DNA polymerase
● B) RNA polymerase
● C) Helicase
● D) Ligase
Answer: C) Helicase
Explanation: Helicase is the enzyme that unwinds the double helix, separating the two strands
so they can be copied during DNA replication.
6. What is the purpose of a test cross?
● A) To determine the genotype of an individual with a dominant phenotype.
● B) To increase genetic diversity in a population.
● C) To identify genetic mutations in a population.
● D) To measure the recombination frequency between two genes.
Answer: A) To determine the genotype of an individual with a dominant phenotype.
Explanation: A test cross involves crossing an individual with a dominant phenotype (but
unknown genotype) with a homozygous recessive individual to reveal whether the dominant
individual is homozygous or heterozygous.
7. What type of inheritance is exemplified by human blood types, where both A and B
alleles are expressed in the AB blood type?
● A) Incomplete dominance
(For High Study)
1. What is the role of messenger RNA (mRNA) in the cell?
● A) It carries amino acids to ribosomes for protein synthesis.
● B) It carries genetic information from DNA to ribosomes.
● C) It helps fold proteins into their functional forms.
● D) It synthesizes DNA from an RNA template.
Answer: B) It carries genetic information from DNA to ribosomes.
Explanation: mRNA is transcribed from DNA in the nucleus and then carries the code to
ribosomes in the cytoplasm, which directs protein synthesis.
2. Which of the following best describes a gene?
● A) A molecule that stores cellular energy.
● B) A segment of DNA that codes for a protein or RNA.
● C) A molecule that transports oxygen in the bloodstream.
● D) The structure where proteins are assembled.
Answer: B) A segment of DNA that codes for a protein or RNA.
Explanation: A gene is a specific sequence of DNA that contains the instructions to make a
functional product, either a protein or a form of RNA.
3. Which of these is NOT an example of a mutation?
● A) Substitution of one base for another in a DNA sequence.
● B) Deletion of a segment of DNA.
● C) Duplication of a chromosome segment.
● D) Transcription of mRNA from DNA.
Answer: D) Transcription of mRNA from DNA.
Explanation: Transcription is a normal process that converts DNA into mRNA. Mutations
involve changes in the DNA sequence, such as substitutions, deletions, or duplications.
, 4. In Mendelian genetics, what ratio of phenotypes would you expect from a monohybrid
cross between two heterozygous parents (Aa x Aa)?
● A) 1:1
● B) 1:2:1
● C) 3:1
● D) 9:3:3:1
Answer: C) 3:1
Explanation: In a monohybrid cross between two heterozygous parents, the offspring
phenotypes will show a 3:1 ratio, where three display the dominant phenotype and one display
the recessive phenotype.
5. Which enzyme is responsible for unwinding the DNA helix during DNA replication?
● A) DNA polymerase
● B) RNA polymerase
● C) Helicase
● D) Ligase
Answer: C) Helicase
Explanation: Helicase is the enzyme that unwinds the double helix, separating the two strands
so they can be copied during DNA replication.
6. What is the purpose of a test cross?
● A) To determine the genotype of an individual with a dominant phenotype.
● B) To increase genetic diversity in a population.
● C) To identify genetic mutations in a population.
● D) To measure the recombination frequency between two genes.
Answer: A) To determine the genotype of an individual with a dominant phenotype.
Explanation: A test cross involves crossing an individual with a dominant phenotype (but
unknown genotype) with a homozygous recessive individual to reveal whether the dominant
individual is homozygous or heterozygous.
7. What type of inheritance is exemplified by human blood types, where both A and B
alleles are expressed in the AB blood type?
● A) Incomplete dominance
