Class 12 Biology MCQ – Principles of Inheritance and Variation


This set of Class 12 Biology Chapter 5 Multiple Choice Questions & Answers (MCQs) focuses on “Principles of Inheritance and Variation”. These MCQs are created based on the latest CBSE syllabus and the NCERT curriculum, offering valuable assistance for exam preparation.

1. Which of the following is a recessive trait in pea plants?
a) Dwarf stem height
b) Violet flowers
c) Axial flowers
d) Inflated pods
View Answer

Answer: a
Explanation: Recessive traits are the ones that require both alleles to be present to result in the expression of the gene product. Of the mentioned traits, only dwarf stem height is a recessive trait.

2. Round and wrinkled seeds were one of the contrasting traits used by Mendel to devise the laws of inheritance.
a) True
b) False
View Answer

Answer: a
Explanation: Mendel used 7 different pairs of contrasting traits to devise the laws of inheritance. These also included the mentioned round and wrinkled seeds. Round seeds are dominant, whereas wrinkled seeds are recessive.

3. If you were to sample garden pea plants in Mendel’s garden, which of the following statements would hold?
a) Round seeds were more abundant than wrinkled seeds
b) Wrinkled seeds were more abundant than round seeds
c) Both round and wrinkled seeds were equally abundant
d) Answer depends on the time of day when sampling is done
View Answer

Answer: a
Explanation: Dominant allele can express even in the presence of a recessive allele. Hence dominant phenotype is more common. Round seeds are dominant over wrinkled seeds; hence would be more abundant.

4. What was the model organism used by Mendel to give the laws of inheritance?
a) Garden peas
b) Wild peas
c) Basket peas
d) Bottle gourd
View Answer

Answer: a
Explanation: Mendel was a priest at a church. He grew garden peas behind the church. He studied the passing of characters within these by the process of hybridization.

5. Which of the following is not an attribute associated with Mendel’s studies?
a) Mathematical analysis
b) Larger sampling size
c) A reliable and credible data source generation
d) Frequent killing of the model organism
View Answer

Answer: d
Explanation: Mendel’s studies were one of its kind as he used the robust scientific method, mathematical and statistical tools to study a large sample of pea plants. He also created a reliable and credible data source to look upon frequently for deriving conclusions. Additionally, his techniques were ethical even in today’s standard and involved proper maintenance of the model organism in hand.
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6. Which of the following is not a pair of contrasting traits studied by Mendel?
a) Green and yellow pods
b) Full and constricted pods
c) Axial and terminal flowers
d) Pink and white flowers
View Answer

Answer: d
Explanation: Mendel’s studies involved study of seven pairs of contrasting traits. These included green and yellow pods, full and constricted pods, axial, and terminal flowers. The flower color pair studied was violet and white.

7. What was the type of pea lines used by Mendel?
a) True-breeding
b) False-breeding
c) Not breeding
d) Indefinitely breeding
View Answer

Answer: a
Explanation: True-breeding pea lines were used by Mendel to study the processes. These are plants that are homozygous, hence have two copies of the same alleles.

8. What method is used to produce a true-breeding line?
a) Self-pollination
b) Cross-pollination
c) Artificial pollination
d) Allogamy
View Answer

Answer: a
Explanation: A true-breeding line is the one that is homozygous for a given allele. This can be achieved by repeated self-pollination over many generations. This exposes the traits encoded by recessive alleles, which would otherwise be suppressed by the presence of dominant alleles.

9. Which of the following is a dominant character in pea plants?
a) Tall stem height
b) White flowers
c) Terminal flowers
d) Constricted pods
View Answer

Answer: a
Explanation: Dominant characters are the ones that are expressed even when a single allele of the gene is present. Of the mentioned traits, only tall stem height is a dominant character.

More MCQs on Class 12 Biology Chapter 5:

Chapter Wise MCQs for Class 12 Biology

To practice all chapters and topics of class 12 Biology, here is complete set of 1000+ Multiple Choice Questions and Answers.

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