NumicornNumicornLearn, solve, progress

Genetics and Molecular Biology Practice Tests

These Grade 12 Science practice tests develop Genetics and Molecular Biology skills through questions on DNA, RNA, gene expression, inheritance, biotechnology, disease, and molecular experiments.

Skills covered

  • Analyzing nucleotide structure, DNA replication, transcription, RNA processing, translation, mutations, and operons
  • Applying Mendelian inheritance, non-Mendelian patterns, linkage, recombination, population genetics, genetic drift, founder effects, and gene flow
  • Explaining enhancers, repressors, epigenetics, microRNA, alternative splicing, PCR, electrophoresis, sequencing, and CRISPR targeting
  • Connecting oncogenes, tumor suppressors, apoptosis, telomeres, stem cells, gene therapy, viral vectors, vaccines, and tumor heterogeneity
  • Evaluating controls, expression assays, cDNA, pedigrees, protein detection, microarrays, null hypotheses, coverage, replication, and conclusions

How to use these practice tests

Trace the flow from sequence to expression to phenotype. For laboratory questions, identify the control, variable, measurement, and limitation before selecting a conclusion.

For more Grade 12 Science practice, return to the Grade 12 Science category.

Select a test

5 Tests
1. Test2. Test3. Test4. Test5. Test

2. Test

Grade 12 Genetics and Molecular Biology Practice Tests

Practice Grade 12 Science questions about DNA, RNA, gene expression, inheritance, population genetics, biotechnology, cancer biology, and molecular experiments.

Choose the best answer. Connect molecular mechanisms to inheritance or phenotype, and interpret experimental evidence within its limits.

10 Questions
0/10 Questions0 %
Correct 0
Incorrect 0
Unanswered 10
1. QuestionMultiple choice

What is incomplete dominance?

Please select an answer first.

Correct answer: A

The correct answer is A heterozygote shows an intermediate phenotype between the two homozygotes.

  1. Identify the molecular genetics concept: Determine whether the question concerns DNA, RNA, inheritance, regulation, biotechnology, disease, or experimental analysis.
  2. Apply the genetic principle: In incomplete dominance, neither allele is completely dominant, producing an intermediate phenotype in the heterozygote.
  3. Connect sequence, expression, and phenotype: The correct answer is A heterozygote shows an intermediate phenotype between the two homozygotes.

In incomplete dominance, neither allele is completely dominant, producing an intermediate phenotype in the heterozygote.

2. QuestionMultiple choice

What is codominance?

Please select an answer first.

Correct answer: B

The correct answer is Both alleles are visibly expressed in the heterozygote.

  1. Identify the molecular genetics concept: Determine whether the question concerns DNA, RNA, inheritance, regulation, biotechnology, disease, or experimental analysis.
  2. Apply the genetic principle: Codominant alleles contribute distinct, observable products or traits at the same time.
  3. Connect sequence, expression, and phenotype: The correct answer is Both alleles are visibly expressed in the heterozygote.

Codominant alleles contribute distinct, observable products or traits at the same time.

3. QuestionMultiple choice

Why are X-linked recessive traits often more common in XY individuals?

Please select an answer first.

Correct answer: C

The correct answer is An XY individual has only one X chromosome and may express a recessive allele on it.

  1. Identify the molecular genetics concept: Determine whether the question concerns DNA, RNA, inheritance, regulation, biotechnology, disease, or experimental analysis.
  2. Apply the genetic principle: A single X-linked allele can be expressed when there is no second X chromosome with a dominant allele.
  3. Connect sequence, expression, and phenotype: The correct answer is An XY individual has only one X chromosome and may express a recessive allele on it.

A single X-linked allele can be expressed when there is no second X chromosome with a dominant allele.

4. QuestionMultiple choice

What is crossing over?

Please select an answer first.

Correct answer: D

The correct answer is Exchange of corresponding DNA segments between homologous chromosomes during meiosis.

  1. Identify the molecular genetics concept: Determine whether the question concerns DNA, RNA, inheritance, regulation, biotechnology, disease, or experimental analysis.
  2. Apply the genetic principle: Crossing over creates new combinations of alleles and increases genetic variation in gametes.
  3. Connect sequence, expression, and phenotype: The correct answer is Exchange of corresponding DNA segments between homologous chromosomes during meiosis.

Crossing over creates new combinations of alleles and increases genetic variation in gametes.

5. QuestionMultiple choice

What does it mean when two genes are linked?

Please select an answer first.

Correct answer: A

The correct answer is They are close together on the same chromosome and tend to be inherited together.

  1. Identify the molecular genetics concept: Determine whether the question concerns DNA, RNA, inheritance, regulation, biotechnology, disease, or experimental analysis.
  2. Apply the genetic principle: Linked genes do not assort independently as often as genes on different chromosomes, although crossing over can separate them.
  3. Connect sequence, expression, and phenotype: The correct answer is They are close together on the same chromosome and tend to be inherited together.

Linked genes do not assort independently as often as genes on different chromosomes, although crossing over can separate them.

6. QuestionMultiple choice

What does recombination frequency estimate?

Please select an answer first.

Correct answer: B

The correct answer is The proportion of offspring or gametes with new allele combinations for linked genes.

  1. Identify the molecular genetics concept: Determine whether the question concerns DNA, RNA, inheritance, regulation, biotechnology, disease, or experimental analysis.
  2. Apply the genetic principle: Higher recombination frequency generally indicates that linked genes are farther apart on a chromosome.
  3. Connect sequence, expression, and phenotype: The correct answer is The proportion of offspring or gametes with new allele combinations for linked genes.

Higher recombination frequency generally indicates that linked genes are farther apart on a chromosome.

7. QuestionMultiple choice

Under Hardy–Weinberg conditions, which expression gives the genotype-frequency relationship for two alleles?

Please select an answer first.

Correct answer: C

The correct answer is p2+2pq+q2=1p^2 + 2pq + q^2 = 1.

  1. Identify the molecular genetics concept: Determine whether the question concerns DNA, RNA, inheritance, regulation, biotechnology, disease, or experimental analysis.
  2. Apply the genetic principle: For allele frequencies p and q, the expected genotype frequencies are p², 2pq, and q², which sum to one.
  3. Connect sequence, expression, and phenotype: The correct answer is p2+2pq+q2=1p^2 + 2pq + q^2 = 1.

For allele frequencies p and q, the expected genotype frequencies are p², 2pq, and q², which sum to one.

8. QuestionMultiple choice

What is a population bottleneck?

Please select an answer first.

Correct answer: D

The correct answer is A sharp reduction in population size that can reduce genetic variation by chance.

  1. Identify the molecular genetics concept: Determine whether the question concerns DNA, RNA, inheritance, regulation, biotechnology, disease, or experimental analysis.
  2. Apply the genetic principle: When few survivors reproduce after a population crash, their alleles may be overrepresented in later generations.
  3. Connect sequence, expression, and phenotype: The correct answer is A sharp reduction in population size that can reduce genetic variation by chance.

When few survivors reproduce after a population crash, their alleles may be overrepresented in later generations.

9. QuestionMultiple choice

What is the founder effect?

Please select an answer first.

Correct answer: A

The correct answer is A new population’s allele frequencies reflect the small group that established it.

  1. Identify the molecular genetics concept: Determine whether the question concerns DNA, RNA, inheritance, regulation, biotechnology, disease, or experimental analysis.
  2. Apply the genetic principle: A small founding group may carry a nonrepresentative sample of the source population’s genetic variation.
  3. Connect sequence, expression, and phenotype: The correct answer is A new population’s allele frequencies reflect the small group that established it.

A small founding group may carry a nonrepresentative sample of the source population’s genetic variation.

10. QuestionMultiple choice

What is gene flow?

Please select an answer first.

Correct answer: B

The correct answer is Movement of alleles between populations through migration and reproduction.

  1. Identify the molecular genetics concept: Determine whether the question concerns DNA, RNA, inheritance, regulation, biotechnology, disease, or experimental analysis.
  2. Apply the genetic principle: Gene flow can introduce alleles into a population and reduce genetic differences between populations.
  3. Connect sequence, expression, and phenotype: The correct answer is Movement of alleles between populations through migration and reproduction.

Gene flow can introduce alleles into a population and reduce genetic differences between populations.

Previous testNext test