Free Mendel's Laws of Inheritance MCQs with Answers
130 Mendel's Laws of 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.
Mendelian inheritance explains how alleles separate into gametes and assort during reproduction, producing predictable genotype and phenotype ratios. Questions cover dominance, recessiveness, homozygous and heterozygous conditions, the laws of segregation and independent assortment, monohybrid and dihybrid crosses, test crosses and the limits caused by linked genes.
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130 questions · page 6 of 7
- A. Dominance
- B. Incomplete dominance
- C. Codominance
- D. Over-dominance
Explanation: Incomplete dominance is when a dominant allele, or form of a gene, does not completely mask the effects of a recessive allele, and the…
Correct answer: Incomplete dominance- A. Dominance
- B. Codominance
- C. Pleiotropy
- D. Epistasis
Explanation: Epistasis is an example of nonallelic interactions. It is defined as the phenomenon in which the effect caused by genes on one locus…
Correct answer: Epistasis- A. 3/16 Tall-round ; 3/16 dwarf-wrinkled
- B. 9/16 Tall-wrinkled ; 3/16 dwarf-round
- C. 9/16 Tall-round ; 3/17 Dwarf-round
- D. 3/16 Tall-wrinkled ; 3/16 Dwarf-round
Explanation: As we talk about the F1 generation, we can assume them to be heterozygous for both characteristics.
Correct answer: 3/16 Tall-wrinkled ; 3/16 Dwarf-round- A. ¼ purple ; ¾ white
- B. ¼ white ; ¾ purple
- C. All white
- D. All purple
Explanation: As it is mentioned in the question that it is pure breeding, we can assume the pea plants involved in the breeding to be homozygous…
Correct answer: All purple- 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