Home » Principles of Inheritance and Variation Class 12 Biology MCQ With Solutions

Principles of Inheritance and Variation Class 12 Biology MCQ With Solutions

Update on: 02 Feb 2024, 11:01 AM

The Principles of Inheritance and Variation Class 12 Biology MCQ with Answers has been organized according to the latest exam pattern in the CBSE Class 12 Biology syllabus for the upcoming CBSE Class 12 Biology Exam. Principles of Inheritance and Variation covers topics like mendelian genetics, chromosomal Theort of inheritance, Linkage and sex determination, Mutation and Genetic Disorders, These questions are designed to help students understand the concept thoroughly. They are helpful for revision and for grasping the concepts effectively. The MCQ questions for Chapter 4 Principles of Inheritance and Variation cover in-text book questions and important topics to help students assess their preparation level for CBSE board exams.

Recent – Reproductive Health Class 12 Biology MCQ With Solutions

CBSE Class 12 Chapter 4 Principles of Inheritance and Variation MCQs

Check below the  CBSE Class 12 Biology MCQ with answers and Clear your idea of Chapter 4 Principles of Inheritance and Variation.

Q.1. In a pedigree analysis, a mutation in recessive gene would be expressed only in

(a) recessive homozygous condition
(b) recessive heterozygous condition
(c) dominant homozygous condition
(d) both (a) and (b)

Answer
(a): Diploid organisms carry two copies of each gene, they may carry identical alleles, that is, being homozygous for a gene, or carry different alleles, that is, being heterozygous for a gene. In a recessive mutation, both alleles must be mutant in order for the mutant phenotype to be observed; therefore, the individual must be homozygous for the mutant allele to show the mutant phenotype.

Check Out – 11 Most Important Graphics of NCERT Class 12th Biology That You Cannot Miss

Q.2. Linked genes on homologous chromosome can be separated due to

(a) recombination (b) inversion (c) point mutation (d) none of these.

Answer
(a): Linked genes can be separated by recombination in which homologous chromosomes exchange genetic information during meiosis; this results in parental, or non recombinant genotypes, as well as a smaller proportion of recombinant genotypes.

 

Practice More – CBSE Sample Paper Class 12 for 2023-24 Boards | FREE PDF from MTG

Q.3. The non-disjunction of 21st pair of autosomal chromosome leads to

(a) Sickle cell anaemia
(b) Klinefelter’s syndrome
(c) Turner’s syndrome
(d) Down’s syndrome.

Answer

(d): Down’s syndrome is usually due to non-disjunction of chromosome 21 that results in an embryo with three copies of chromosome 21 instead of the usual two. Prior to or at conception, a pair of 21st chromosomes in either the sperm or the egg fails to separate.

 

Q.4. In a Mendelian dihybrid cross, the phenotypic ratio obtained in F2 progeny is

(a) 9 : 7
(b) 9 : 3 : 3 : 1
(c) 9 : 3 : 4
(d) 1 : 2 : 2 : 4 : 1 : 2 : 1 : 2 : 1.

Answer
(b): According to the law of independent assortment, a phenotypic ratio among the progeny of a dihybrid cross is 9 : 3 : 3 : 1 .

 

Q.5. The human blood groups are determined by

(a) 4 alleles in which IA is dominant.
(b) 3 alleles in which IA and IB are codominant.
(c) 3 alleles in which none is dominant.
(d) 3 alleles in which IA and i are codominant.

Answer
(b): Human blood groups are determined by three alleles, viz., IA, IB and i. IA, IB are co-dominant and i is recessive

 

Q.6. In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased?

(a) 100% (b) 50% (c) 75% (d) 25%

Answer
(d): Sickle cell anaemia is an autosomal recessive disorder.
Answer 6

 

Q.7. On selfing a heterozygous round and yellow seeded plants, the production of heterozygous for both the traits would be

(a) 9/16 (b) 3/16
(c) 1/16 (d) 4/16

Answer
(d): The heterozygous for both seed shape and colour (RrYy) produced during dihybrid cross are four out of sixteen
selfing a heterozygous round and yellow seeded plants

 

Q.8. The production of gametes by the parents, formation of zygotes, the F1 and F2 plants, can be understood from a diagram called

(a) net square (b) bullet square (c) punch square (d) Punnett square.

Answer
(d): The prodcuction of gametes by the parents, formation of the zygotes, the F1 and F2 plants can be understood from a diagram called Punnett square developed by a British geneticist, Reginald C. Punnett.

 

Q.9. Which of the following does not follow Mendel’s law of dominance?

(a) Pisum sativum
(b) Mirabilis jalapa
(c) Lathyrus odoratus
(d) Oenothera lamarckiana

Answer
(b): Mirabilis jalapa shows incomplete dominance which is an exception to law of dominance. Incomplete dominance is the condition when a dominant allele, or form of a gene, does not completely mask the effects of a recessive allele, and the organism’s resulting physical appearance shows a blending of both alleles.

 

Q.10. The cross between white eyed female Drosophila and a red eyed male Drosophila would lead to the production of

(a) red eyed males and red eyed females
(b) white eyed males and white eyed females
(c) red eyed females and white eyed males
(d) white eyed males and red eyed females.

Answer
(c): The cross of white eyed female with red eyed male gives red eyed females and white eyed males. Rarely this cross may give all white eyed females and red eyed males. This results from non-separation of two homologous X chromosomes during anaphase I of meiosis. Both X chromosomes go together to same pole resulting in formation of one XXY i.e., white eyed female and red eyed males. This phenomenon is known as non-disjunction of two X chromosomes.

 

We hope the MCQs for the CBSE Class 12 Biology Chapter 4 on Principles of Inheritance and Variation are helpful for your board exam preparation.

Keep learning and stay updated with us for more CBSE exam updates.


 

Leave a Reply

Your email address will not be published. Required fields are marked *

Update on: 25 Apr 2024, 04:03 PM

Are you a student of Class 6 and feeling overwhelmed by the syllabus? You must be going through longer chapters, complex topics, and detailed explanations as compared to your 5th Standard syllabus. The pressure is natural because 6th Standard takes you to the next level…...

Update on: 15 Apr 2024, 11:50 AM

While there are numerous books for CBSE exams out there, one that bears the title “CBSE Champion” is bound to have something worthwhile for you. This CBSE book stands out as it is applauded and appreciated by an endless number of students, parents, and teachers.…...

Update on: 15 Apr 2024, 11:20 AM

As a student or a guardian, we keep hearing the importance of CBSE and its curriculum almost daily in our academic life. But how many of you emphasize 100% learning of the CBSE syllabus based on the latest patterns set by CBSE? We all manifest…...

Update on: 15 Apr 2024, 10:40 AM

In 2024, over 39 lakh students appeared for CBSE exams from classes 10th and 12th. And when we talk about all students taking CBSE exams from class 9th to class 12th, the number will increase significantly. So, as a part of this huge student crowd,…...

Update on: 15 Apr 2024, 10:20 AM

In the past few years, the Central Board of Secondary Education has had tremendous turnarounds! Everything from the exam pattern to the evaluation methods has had a significant change. For the session 2024-25, CBSE has again changed the evaluation pattern for the class 12 exam.…...

Update on: 14 Apr 2024, 03:01 PM

Students of classes 10 and 12 know the pressure of CBSE Board exams. They are under a constant stress shadow to outshine themselves. Thus, they are always searching for ways to excel in their CBSE exams. However, this search often leads to confusion since the…...

Update on: 07 Apr 2024, 05:23 PM

Salt water is a good conductor of electricity! Farhan and other ICE students read it while Rancho applied this basic Science theory in a real-life scenario. Ever wondered why only Rancho could implement it, that too within fraction of seconds? Probably he was prone to…...

Update on: 06 Apr 2024, 05:55 PM

Conquering the CBSE Class 9th exam must have been a tough nut to crack. However, doing well in the 9th class raises confidence and morale for the ultimate battle – CBSE Class 10 Board exams. Class 10th board exams hold the utmost importance in a…...

Update on: 06 Apr 2024, 05:53 PM

As the academic year 2023-2024 comes to an end and session 2024-2025 is ready to begin, the Central Board of Secondary Education (CBSE) has released the curriculum for the upcoming academic session of 2024-2025. Along with the curriculum, CBSE has also released sample papers and…...

Update on: 06 Apr 2024, 05:50 PM

The Central Board of Secondary Education, CBSE, has issued the Class 10 Maths Syllabus 2024–25. Since the new academic year has begun, students should start preparing right away so that they won’t be overwhelmed at the last minute. This article contains the class 10 CBSE…...