Free Inheritance MCQs with Answers
1,238 Inheritance MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Mendel's laws explain segregation, independent assortment and the prediction of genetic ratios using alleles, genotypes and phenotypes. The chapter also covers linked genes, recombination and crossing over during meiosis, then applies pedigree reasoning to X-linked recessive traits, which show different inheritance patterns in males and females.
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541. A man expresses a certain X-linked recessive genetic disorder. Which of the following must be true?
- A. His mother expresses the disorder
- B. His father passed on the allele for the disorder
- C. His mother passed on the allele for the disorder
- D. None of these options is correct
Explanation: An X-linked disease can only be passed from father to daughter, so option C is most likely the correct option.
Correct answer: His mother passed on the allele for the disorder- A. There is a one in four chance the son will be affected.
- B. There is a three in four chance that the son will be affected.
- C. There is a one in two chance that the son will be affected.
- D. The son cannot be affected.
Explanation: A man passes his Y chromosome to his son. As the disease is X dominant, an affected father will not pass the disease to his son.
Correct answer: The son cannot be affected.- A. Law of independent assortment
- B. Law of Segregation
- C. Test cross
- D. Incomplete dominance
Explanation: d) Incomplete dominance:Incomplete dominance is a form of inheritance where the heterozygous phenotype is an intermediate blend of the two…
Correct answer: Incomplete dominance- A. TTYy X Ttyy
- B. TT X tt
- C. Both Options A and B are correct
- D. None of these options are correct
Explanation: The cross between two monohybrid traits (TT and tt) is called a Monohybrid Cross." Monohybrid cross is responsible for the inheritance of…
Correct answer: TT X tt- A. 7
- B. 6
- C. 8
- D. 11
Explanation: The gene encoding the blue pigment (OPN1SW) is located on the long arm of chromosome 7.
Correct answer: 7- A. The traits of a test cross are homozygous dominant
- B. Test cross can only be used for monohybrid and dihybrid crosses
- C. It is a tool used by researchers to determine the genotype of earlier generations
- D. Both A and B
Explanation: A test cross is a genetic cross between an organism with a dominant phenotype, but unknown genotype, and an organism with a homozygous…
Correct answer: It is a tool used by researchers to determine the genotype of earlier generations- A. Genome
- B. Gene pool
- C. Genetic group
- D. Genomic library
Explanation: The term "gene pool" refers to the total collection of different genes and their alleles within a specific population.
Correct answer: Gene pool- A. Dominance
- B. Pleiotropy
- C. Epistasis
- D. None of these
Explanation: Dominance refers to the relationship between two alleles of a gene, where one allele masks or overrides the expression of the other allele…
Correct answer: Epistasis549. If a heterozygous individual shows the complete effect of both alleles, the type of inheritance be?
- A. Complete dominance
- B. Non dominance
- C. Incomplete dominance
- D. Codominance
Explanation: Complete dominance is a genetic phenomenon in which one version of a gene (the dominant allele) masks the effect of the other version (the…
Correct answer: Codominance- A. Heterozygote
- B. Homozygote
- C. Both A & B
- D. None of the above
Explanation: Option A: Heterozygote refers to an individual who has two different alleles for a particular gene, meaning they have a heterozygous…
Correct answer: Heterozygote- A. Pseudoautosomal
- B. Sex-Linked
- C. Both A & B
- D. None of the Above
Explanation: Option A: Pseudoautosomal: Refers to a region on the X and Y chromosomes where they share genetic material, but a trait determined by a…
Correct answer: Sex-Linked- A. Half Dominance
- B. Partial Dominance
- C. Codominance
- D. None of these
Explanation: Partial dominance is generally considered to be a type of incomplete dominance, with the heterozygote resembling one homozygous more than…
Correct answer: Partial Dominance- A. Morphology
- B. Physiology
- C. Genetics
- D. All of these
Explanation: The phenotype represents morphology because it includes the physical characteristics and appearance of an organism that are observable to…
Correct answer: Morphology- A. Hemophilia
- B. Color blindness
- C. Huntington's disease
- D. Cystic fibrosis
Explanation: Ans is D. "Cystic fibrosis" is due to an autosomal recessive allele of a gene.
Correct answer: Cystic fibrosis- A. 25%
- B. 50%
- C. 75%
- D. 1%
Explanation: If a certain type of plant is only tall when it has a heterozygous genotype, it suggests that the tall trait is dominant and the short…
Correct answer: 50%- A. 1811
- B. 1801
- C. 1911
- D. 1901
Explanation: ABO Blood group was discovered by Karl Landsteiner in "1901". Option A, B and C are incorrect.
Correct answer: 1901- A. 1
- B. 2
- C. 3
- D. None of these
Explanation: Correct option: C (Fact) (3 pairs of genes control skin color in man). Skin color in humans is determined by multiple genes, specifically…
Correct answer: 3- A. Mathematical method
- B. Pedigree method
- C. Statistical method
- D. Genetic method
Explanation: A pedigree is a genetic representation of a family tree that diagrams the inheritance of a trait or disease through several generations.
Correct answer: Pedigree method- A. Variation
- B. New traits in species
- C. All of these
- D. Recombinant genes
Explanation: Crossing over is the exchange of genetic material between homologous chromosomes.
Correct answer: All of these560. Hemophilia is a:
- A. None of these
- B. Both of these
- C. Mendelian trait
- D. Chromosomal disorder
Explanation: Hemophilia is a Mendelian trait that is also an X chromosome-linked recessive disorder.
Correct answer: Both of these