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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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Mendel's Laws of InheritanceGene Linkage and Crossing OverX-linked Recessive Inheritance
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1,238 questions · page 26 of 62

501. Where the heterozygote is indistinguishable from one of the homozygotes the allele involved is said to be?

  • A. Recessive
  • B. Dominant
  • C. Both A and B
  • D. None of these

Explanation: In the dominant allele, in both homozygous and heterozygous form the genotype cannot be known as the phenotype in both is same.

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Correct answer: Dominant

502. Genes for color blindness form _ linkage group on human_ chromosome

  • A. 2, Y
  • B. 1, Y
  • C. 2,X
  • D. 1,X

Explanation: Option D is correct since genes for color blindness, hemophilia, and go out form 1 linkage group on human X chromosome.

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Correct answer: 1,X

503. Such inheritance in which traits vary quantitatively is called ------

  • A. Continuously varying trait
  • B. Incomplete dominance
  • C. Test cross
  • D. Polygenic inheritance

Explanation: Option D is correct since 'polygenic inheritance' is also involved in 'quantitative traits', in which multiple gene loci each contribute…

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Correct answer: Polygenic inheritance

504. Assuming that blood type is not a sex-linked trait, what is the probability that a mother with genotype "A/O" and a father with genotype "A/B" will have a child with type B blood?

  • A. 50%
  • B. 25%
  • C. 75%
  • D. 0%

Explanation: The parental gametes would be A, O, A and B. The possible combinations can be AO, AA, AB, BO.

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Correct answer: 25%

505. In fruit flies, white eyes are produced by a dominant X-linked mutation, with the wild-type being red-eyed. If a white-eyed male is mated with a red-eyed female, what will be the phenotype of the resulting offspring?

  • A. Half the females will have white eyes
  • B. All the males will have white eyes
  • C. Half the males will have white eyes
  • D. All the females have white eyes

Explanation: As the male has the genotype XwY, with Xw coding for the gene of white eyes.

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Correct answer: All the females have white eyes

506. Which of the following characters of pea plant is dominant?

  • A. Yellow pods
  • B. White flowers
  • C. Wrinkled seeds
  • D. Axial flowers

Explanation: In a homozygous pea plant, axial flowers (A) are dominant over terminal flowers (a)

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Correct answer: Axial flowers

507. The gene which cannot be determined by observing the organism is?

  • A. Dominant
  • B. Allele
  • C. Phenotype
  • D. Recessive

Explanation: Recessive allele cannot be detected because its effect is masked by the dominant gene so in heterozygous we can not observe and recognise…

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Correct answer: Recessive

508. The genes which do not follow law of independent assortment?

  • A. Recessive genes.
  • B. Dominant genes.
  • C. Crossed genes.
  • D. Linked genes.

Explanation: The genes that do not follow the law of independent assortment are called linked genes.

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Correct answer: Linked genes.

509. A man with type A- blood and a woman with type AB+ blood have a child. Which blood type is impossible for that child to have?

  • A. A-.
  • B. B-.
  • C. AB+.
  • D. O-.

Explanation: The ABO blood type system is based on the presence of two antigens (A and B) on the surface of red blood cells and two antibodies (anti-A…

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Correct answer: O-.

510. The alternative forms of the same gene are called which of the following?

  • A. Locus
  • B. Gene
  • C. Allele
  • D. Phenotype

Explanation: Alleles are a pair of genes that occupy a specific location on a particular chromosome and control the same trait.

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Correct answer: Allele

511. A researcher is studying a population of insects and notices that 60% have red eyes, 30% have apricot eyes, 5% have white eyes and 5% have pink eyes. Which of these eye colors would be designated the wild type?

  • A. Red
  • B. White
  • C. Pink
  • D. All of these

Explanation: Option A is correct since normal wild type is the typical (or the most common) form, appearance, or strain,n existing in the wild.

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Correct answer: Red

512. The number of linkage groups in humans is?

  • A. 1/21
  • B. 23
  • C. 1/23
  • D. 1/24

Explanation: Option B is correct since the number of linkage groups in humans is equal to the haploid number of chromosomes.

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Correct answer: 23

513. Gene is the molecular unit of the following:

  • A. DNA
  • B. RNA
  • C. Heredity
  • D. Genotype

Explanation: Option C is correct since the gene is the molecular unit of heredity is a fact.

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Correct answer: Heredity

514. In mammals, which type of phenotypic expression will show recessive traits more frequently in males than females?

  • A. Incomplete dominance
  • B. Complete dominance
  • C. Codominance
  • D. X-linked

Explanation: Option D is correct as males have an X and a Y chromosome, and if the recessive alleles are linked to the X chromosome, then it will be…

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Correct answer: X-linked

515. Two pea plants are crossed. One plant is homozygous dominant for purple flowers, and the other is homozygous recessive for white flowers. What fraction of the F2 population will have white flowers?

  • A. 1/4
  • B. 1/2
  • C. 1/8
  • D. 1/16

Explanation: When both parents are crossed, we will get an F1 generation with heterozygous purple flowers.

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Correct answer: 1/4

516. What contributes to genetic variation during human reproduction?

  • A. Random mating
  • B. Non-random mating
  • C. Independent assortment
  • D. All of these

Explanation: The correct option is D. Non-random mating can also be outbreeding, wherein there is an increased probability that individuals with a…

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Correct answer: All of these

517. The specific location of gene and DNA sequence on a chromosome is called?

  • A. Population
  • B. Locus
  • C. Allele
  • D. None of these

Explanation: Locus is the physical site or location of a specific gene on a chromosome.

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Correct answer: Locus

518. The region of DNA that encodes a functional RNA or protein product is called?

  • A. Clone
  • B. Gene
  • C. Phenotype
  • D. Genotype

Explanation: Gene is the basic unit of biological information. In fact, DNA stores all sorts of biological information coded in the sequence of its…

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Correct answer: Gene

519. All chromosomes other than sex chromosomes are called:

  • A. Autosomes
  • B. Allosomes
  • C. Microsomes
  • D. None of them

Explanation: All chromosomes other than sex chromosomes are called autosomes.

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Correct answer: Autosomes

520. True breeding variety is produced by which of the following?

  • A. Cross fertilization
  • B. Self fertilization
  • C. Both A and B
  • D. None of these

Explanation: B is the correct option because Plants or animals that undergo self-fertilization for several generations, such that their traits under…

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Correct answer: Self fertilization
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