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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1,238 questions · page 61 of 62

  • A. XY
  • B. SRY
  • C. SYX
  • D. SXX

Explanation: Y chromosome has an SRY gene. It is the sex determining region Y gene. It is Y linked gene because it is found only on the Y chromosome.

Correct answer: SRY
  • A. Y-chromosome
  • B. X-chromosome
  • C. Autosome 7
  • D. Autosome 9

Explanation: Red- Green Color blindness is a sex-linked recessive disease which is passed down through the X chromosomes.

Correct answer: X-chromosome
  • A. Dominant genes
  • B. Recessive genes
  • C. Linked genes
  • D. Autosomal genes

Explanation: When the two homozygous parents differing in two pairs of contrasting traits are crossed, the inheritance of one pair is independent of…

Correct answer: Linked genes
  • A. Dominant
  • B. Recessive
  • C. Phenotype
  • D. Alleles

Explanation: Fact. "Allele" is the word that we use to describe the alternative form or versions of a gene.

Correct answer: Alleles
  • A. Polygenic alleles
  • B. Multigenic alleles
  • C. Multiple alleles
  • D. Heterogenic alleles

Explanation: In polygenic inheritance, each allele has a cumulative or additive effect on the phenotype thus generating continuous variation, e.g.

Correct answer: Multiple alleles
  • A. 9:3:3:1
  • B. 9:3:4
  • C. 1:2:1
  • D. 2:11

Explanation: The correct ratio for demonstrating the law of independent assortment is 9:3:3:1.

Correct answer: 9:3:3:1
  • A. Hypostatic
  • B. Epistatic
  • C. Hemistatic
  • D. Neostatic

Explanation: Epistatic is the gene that masks the expression of an allele at a separate locus.

Correct answer: Epistatic
  • A. All red
  • B. All white
  • C. All pink
  • D. 1, red, 2, pink & 1 white ratio

Explanation: When red and white color flowers in Mirabilis jalapa (Four O'Clock Flower) are crossed, the F1 generation will typically display an…

Correct answer: 1, red, 2, pink & 1 white ratio
  • A. Tongue rolling
  • B. Diabetes
  • C. Skin colour
  • D. Eye colour

Explanation: This mcq can only be solved by elimination trick. Tongue rolling is controlled by dominant trait while skin colour is a polygenic trait…

Correct answer: Eye colour
  • A. Option A: Complete-dominance
  • B. Option B: Incomplete dominance
  • C. Option C: Co-dominance
  • D. Option D: None

Explanation: The correct answer is Option B: Incomplete dominance. In cases of incomplete dominance, the heterozygous offspring exhibit a phenotype…

Correct answer: Option B: Incomplete dominance
  • A. Down syndrome
  • B. Klinefelter syndrome
  • C. Phenylketonuria
  • D. Turner syndrome

Explanation: Phenylketonuria (PKU) is a genetic disorder that is caused by a point mutation, specifically a mutation in a single gene known as the PAH…

Correct answer: Phenylketonuria
  • A. Johnson
  • B. Corren
  • C. Tschmarch
  • D. Purkinje

Explanation: The term "Gene" was coined by the Danish botanist Wilhelm Johannsen. He introduced the term 'gene' in the early 20th century to describe…

Correct answer: Johnson
  • A. result of mitosis
  • B. result of meiosis
  • C. actual outcome of a cross
  • D. probable outcome of cross

Explanation: A punnett square is always used to determine the POSSIBLE OUTCOME of a cross and never an actual one because an actual one can never be…

Correct answer: probable outcome of cross
  • A. 0%
  • B. 25%
  • C. 50%
  • D. 75%

Explanation: There is zero possibility that their offspring will have a B-negative blood type

Correct answer: 0%
  • A. Homozygous
  • B. Monoecious
  • C. Heterozygous
  • D. Dioecious

Explanation: An individual with contrasting alleles is called Heterozygous. This means that the organism has two different alleles (such as Tt) for a…

Correct answer: Heterozygous
  • A. 4
  • B. 3
  • C. 2
  • D. 9

Explanation: In a dihybrid cross, two traits are considered, each with two alleles. The result is a 4x4 Punnett square with 16 possible genotypes.

Correct answer: 4
  • A. Monozygous
  • B. Homozygous
  • C. Heterozygous
  • D. Multizygous

Explanation: Heterozygous organisms possess two different alleles for a specific trait, which allows them to exhibit similar phenotypes (observable…

Correct answer: Heterozygous
  • A. One
  • B. Two
  • C. Three
  • D. Four

Explanation: When crossing two alleles 'A' and 'a', the potential genotypes that can be formed are AA, Aa, and aa.

Correct answer: Three
  • A. Sickle cell anemia
  • B. Cooley's anemia
  • C. Microcytic anemia
  • D. Nutritional anemia

Explanation: Thalassaemia major is also known as Cooley's anemia, named after Thomas B.

Correct answer: Cooley's anemia
  • A. Co-dominance
  • B. Over dominance
  • C. Epistasis
  • D. Incomplete dominance

Explanation: In incomplete dominance, the heterozygous phenotype is a blend of the two homozygous phenotypes, resulting in a phenotypic ratio that…

Correct answer: Incomplete dominance